Neurology Volume 72(1) January 6

This week in Neurology® Highlights of the January 6 issue

A CSF biomarker panel for identification of patients with amyotrophic lateral sclerosis The paper identifies the sensitive and specific CSF biomarkers panel for amyotrophic lateral sclerosis (ALS). This will permit earlier and more accurate diagnosis in patients with ALS and will facilitate monitoring of disease progression. See p. 14; Editorial, p. 11

A novel Refsum-like disorder that maps to chromosome 20 The identification of new genes leads to greater understanding of disease mechanisms that in turn provides a platform for developing treatments. The authors describe a new disorder that shares similarities with Refsum disease and show that the gene responsible is located on chromosome 20. See p. 20; Editorial, p. 13

Long-term trends in carpal tunnel syndrome Understanding the epidemiology and treatment of carpal tunnel syndrome has significant health policy implications. This article examines the changes in incidence, surgical treatment, and work-related lost time, and potential reasons for these, over a 25-year period.

Longitudinal prognostic value of serum “free” copper in patients with Alzheimer disease The study shows an association between copper deregulation and unfavorable evolution of cognitive function in patients with Alzheimer disease. It demonstrates that “free” copper—i.e., serum copper not bound to ceruloplasmin— can predict the annual change in MMSE, identifying those patients at higher risk for a more severe decline. See p. 50

Smoking and family history and risk of aneurysmal subarachnoid hemorrhage An interaction between smoking and family history markedly increases the risk of aneurysmal subarachnoid hemorrhage (SAH). This paper suggests that smoking history be considered when counseling family members on the risk of SAH and in determining whether asymptomatic family members might benefit from screening. See p. 69

See p. 33

Frontal FDG-PET activity correlates with cognitive outcome after STN-DBS in Parkinson disease Cognitive changes after STN-DBS in advanced Parkinson disease are closely linked to alterations of FDG-PET activity in multiple brain regions including associative and limbic frontal basal ganglia projection sites and in the left Broca area. This paper examines the underlying mechanisms for these observations. See p. 42

Oral fingolimod (FTY720) in multiple sclerosis: Two-year results of a phase II extension study This study demonstrated that oral fingolimod, a sphingosine-1phosphate receptor modulator currently in phase III trials, provides sustained improvements in MRI and clinical measures of multiple sclerosis disease activity. See p. 73

VIEWS & REVIEWS

Delusional misidentifications and duplications: Right brain lesions, left brain delusions Defining the anatomical lesions and behavioral deficits that underlie delusions can help to identify at-risk patients. This paper provides a brain-behavior understanding for the genesis of misidentification-reduplication delusions. See p. 80

Podcasts can be accessed at www.neurology.org

Copyright © 2009 by AAN Enterprises, Inc.

1

ACKNOWLEDGMENT TO REVIEWERS

John H. Noseworthy, MD Editor-in-Chief Robert A. Gross, MD, PhD Deputy Editor Andrew G. Engel, MD Karen C. Johnston, MD, MSc David S. Knopman, MD Jonathan W. Mink, MD, PhD Richard M. Ransohoff, MD Ryan J. Uitti, MD Bradford B. Worrall, MD Associate Editors

Message from the Editors to our US and International Reviewers

Neurology® received 2,018 new and 539 revised manuscripts (including about 52 new and 15 revised fulllength articles per week) from April 1, 2008, through September 30, 2008. During this period, a total of 3,803 reviews were received. Reviewers are returning papers in an average of 8 days; the average time from submission to first decision for papers chosen for review was 28 days compared to 31 days in this same period during 2007 and 37 days in this same period during 2006. We are able to accept for publication only about 15% of full-length papers and 13% of Clinical/Scientific Notes because we are limited in the number of pages we can publish. We greatly appreciate your making specific comments regarding uniqueness of study populations, novel methods, studies that are especially educational, or new strategies for diagnosing and treating neurologic disease to help us choose the best papers for publication. We heavily rely upon these specific comments in your reviews to assist us in making our decisions. We extend our sincere gratitude for your dedication to the journal, which helps us fulfill our goal of publishing the articles that will most benefit authors and readers of Neurology and improve patient care. To express our thanks, we grant an hour of CME credit, if requested, for each manuscript you review for the journal (maximum of 15 credits per year as determined by ACCME). The following criteria determine whether credit will be granted: “it should be evident that the reviewer has read and understood the content of the manuscript, accompanying figures and tables, supplementary material to be published on the Web site, and references. To receive credit, the reviewer must make comments to the Editor that aid him/her in making an informed decision regarding publication of the manuscript and make substantive suggestions to the author.” Credit is not granted for re-reviews unless the review takes more than one hour and substantial new comments are made for the authors. Please let us know if you would like to do more reviews than we have requested of you. If you have never been invited to review for the journal but are interested in doing so, please supply Donna Larkin at [email protected] with a description of your credentials and experience in the areas in which you are qualified to review. The reviewers listed below with one asterisk have reviewed 5 or more papers. Two asterisks indicate that the reviewer has reviewed 10 or more manuscripts. This list includes those reviewers who returned a review or reviews of initial submissions (re-reviews of the same manuscript are not included) between April 1, 2008, and September 30, 2008. Dag Aarsland Bassel W. Abou-Khalil Lauren E. Abrey Maria Acosta Harold P. Adams* Heather Adams Sophie Justine Adams Charles H. Adler J. Eric Ahlskog* Allen J. Aksamit Adnan Al-Araji Alberto Albanese* James W. Albers Steven M. Albert Mark J. Alberts Megan Christine Alcauskas* Ammar Al-Chalabi

2

Albert P. Aldenkamp Michael P. Alexander Andrei V. Alexandrov Alawi Alsheikh-Ali Eric Altschuler Pierre Amarenco Anthony A. Amato** Melissa Amick Catherine M. Amlie-Lefond Beau M. Ances Frederick Andermann David C. Anderson Robert H. Andres Banu Anlar Pasquale Annunziata Kaarin J. Anstey Angelo Antonini

Copyright © 2009 by AAN Enterprises, Inc.

Nader Antonios Stuart Apfel Liana G. Apostolova Stanley H. Appel Hiba Arif Kimiyoshi Arimura Peter A. Arnett Douglas L. Arnold Isabelle Arnulf Zoe Arvanitakis Eishi Asano Alberto Ascherio J. Wesson Ashford John Attia Sanford Auerbach R. Robert Auger Swee T. Aw Hakan Ay

David L. Bachman Misha-Miroslav Backonja Neeraj Badjatia Joachim M. Baehring* Michael Baier Alison E. Baird* Rohit Bakshi Laura J. Balcer James F. Bale, Jr. Clive Ballard Robert H. Baloh Robert W. Baloh* Brenda L. Banwell Tallie Z. Baram Sergio Baranzini Richard Barbano Roger Barker Frederik Barkhof

Lisa L. Barnes Henry J.M. Barnett Richard J. Barohn Jean-Claude C. Baron Amit Bar-Or William Barr Kevin M. Barrett Russell E. Bartt Walter S. Bartynski George Bartzokis Joshua I. Barzilay Sebastian Bauer Christoph Baumgartner Sallie A. Baxendale Jeffrey J. Bazarian Carl W. Bazil Christopher Beck* Kyra Becker James T. Becker Richard S. Bedlack Michael Benatar Oscar R. Benavente Selim R. Benbadis Martin Bendszus Ralph H. Benedict Jeffrey L. Bennett Susan E. Bennett Merrill D. Benson Henk W. Berendse Richard Beresford Anne T. Berg Daniela Berg Michel J. Berg Donna C. Bergen Joseph R. Berger* Klaus Berger Thomas Berger Gregory K. Bergey Samuel F. Berkovic Gary L. Bernardini James L. Bernat* Charles Bernick Richard A. Bernstein James Berry Elizabeth Berry-Kravis Eric M. Bershad Enrico Bertini Frank Besag Christopher T. Bever, Jr. David Q. Beversdorf Kailash P. Bhatia M. Tariq Bhatti Italo Biaggioni Bibiana Bielekova Marcelo Eduardo Bigal Kevin Biglan Erin D. Bigler José Biller* Daniel Markus Bittner Kevin J. Black

Deborah Lynne Blacker Franz Blaes Fabio Blandini Andrew D. Blann Andrew Bleasel Thomas P. Bleck Karen A. Blindauer Donald Bliwise Warren T. Blume Bernadette Boden-Albala Bradley F. Boeve* Julien Bogousslavsky Richard W. Bohannon Richard Boles Karen I. Bolla Bruno Bonetti Vincenzo Bonifati David C Bonovich Natan M. Bornstein E. Peter Bosch Michael Boska Patrick Bosque Teodoro Bottiglieri Dennis Bourdette Marie-Germaine Bousser James H. Bower John V. Bowler Adam L. Boxer Patricia A. Boyle Craig A. Branch Thomas Brandt* Allison Brashear John C. S. Breitner Susan B. Bressman Bruce J. Brew George J. Brewer Adam M. Brickman Tom Britton Bruno Brochet Martin J. Brodie Amy Brodtmann* Mark B. Bromberg Helen M. Bronte-Stewart Matthijs C. Brouwer* Martin Brown Robert Brown Wolfgang Br¨uck Askiel Bruno Ewout R.P. Brunt Jeffrey R. Buchhalter Aron S. Buchman Dennis Bulman F.S. Buonanno* Jorge G. Burneo Alistair Burns Jeffrey M. Burns Rami Burstein Cheryl D. Bushnell* Neil A. Busis Ken Butcher

Desiree Byrd Rajani Ruth Caesar* J. Gregory Cairncross Nigel J. Cairns Franca Cambi Richard M. Camicioli Vito M. Campese Stephen C. Cannon Roberto Cantello Louis R. Caplan Cynthia M. Carlsson Olli Carpen David B. Carr James E. Carroll Jonathan L. Carter* James S. Castle Luiz H. Castro Angela Freymuth Caveney Gastone G. Celesia Fernando Cendes Jang-Ho Cha Hugues Chabriat David A. Chad David W. Chadwick Ambar Chakravarty Colin Chalk* Marc C. Chamberlain Piu B. Chan Richard K. Chan Phillip F. Chance P. David Charles Seemant Chaturvedi** K. Ray Chaudhuri Honglei Chen Robert Chen Tony Hsiu-Hsi Chen Neil Cherian Monique M. Cherrier William P. Cheshire Marc I. Chimowitz Patrick F. Chinnery Adriano Chio Hyunmi Choi Sudhansu Chokroverty Michael Chopp Kelvin L. Chou Madhuchhanda Choudhary Harry T. Chugani Steve Sanghoon Chung Wendy Chung Andrew J. Church David X. Cifu Jan Claassen Lorraine N. Clark Joseph Classen Jan Maarten Cobben Bernard Cohen Bruce H. Cohen Jeffrey A. Cohen

Stanley N. Cohen Andrew J. Cole John W. Cole Cynthia L. Comella Christopher Commichau Peter Como Anne M. Connolly E. Sanders Connolly Robin A. Conwit Mark Cookson Giovanni Coppola James J. Corbett John R. Corboy Elizabeth Hedlund Corder Jody Corey-Bloom Deborah A. Cory-Slechta H. Branch Coslett Bruce M. Coull Timothy J. Counihan Steven C. Cramer Thomas O. Crawford Alain Créange Bruce Anthony Campbell Cree Marco Crimi Didier Cros Anne H. Cross Helen Cross Beth Crowner Merit E. Cudkowicz* Jeffrey L. Cummings Richard G. Curless Antonio Curra Gary R. Cutter Lucette Adeline Juliette Cysique Marek Czosnyka Kirk R. Daffner* Alain Dagher Nabila Dahodwala Josep O. Dalmau Basil T. Darras Stefano D’Arrigo Jean-Francois Dartigues Richard M. Dasheiff Jasper R. Daube Martin Daumer Nick Davies Larry E. Davis Mark H. De Baets Jan L. De Bleecker Harald De Cauwer Frank-Erik de Leeuw Jerome de Seze Nicola De Stefano Marianne de Visser Darryl C. De Vivo Richard Dees Luc J.P. Defebvre Gregory del Zoppo Neurology 72

Norman R. Delanty Martin B. Delatycki Dean Delis Bart M. Demaerschalk Andrew Demchuk Martha Bridge Denckla Anita DeStefano Orrin Devinsky Richard B. Dewey, Jr. Stephen Dewhurst Feza Deymeer Suhayl S. Dhib-Jalbut Vincenzo Di Lazzaro Salvatore Di Mauro Ramon Diaz-Arrastia Martin Dichgans Bradford Clark Dickerson Hans-Christoph Diener Kathleen B. Digre Marc Dinkin Michael N. Diringer William B. Dobyns David W. Dodick Okan Dogu Dana O. Doheny Geoffrey Alan Donnan Rachelle S. Doody Joseph M. Dooley P. Murali Doraiswamy E. Ray Dorsey* Richard Doty Daniel B. Drachman Jens P. Dreier Peter D. Drummond Ranjan Duara Richard M. Dubinsky John Duda Carole Dufouil Mario F. Dulay Aaron Dumont John S. Duncan Peter James Dyck** Tomasz Dziedzic Donald Easton Jamie L. Eberling George C. Ebers Eric R. Eggenberger Scott Eggers Florian S. Eichler David Eidelberg Benjamin H. Eidelman Rodger J. Elble* Ronald J. Ellis Ronald Emerson Murat Emre Jerome Engel, Jr. Giuseppe Erba Gail Eskes Alberto J. Espay Kevin Ess

January 6, 2009

3

Montserrat Estorch Andrew H. Evans Virgilio Gerald H. Evidente Amelia Evoli* Stewart A. Factor John Y. Fang Martin R. Farlow Matthew Farrer Hassan M. FathallahShaykh Raymond Edward Faught, Jr. Olga Favorova Pierre Fayad Franz Fazekas Antonio Federico Howard Joshua Federoff Andrew Feigin Valery L. Feigin Anthony Feinstein Howard H. Feldman Edward Feldmann Russ J. Ferland Steven Ferris Jose M. Ferro Steven Feske A. James Fessler Doreen Fialho David M. Ficker Terry D. Fife Denise Figlewicz Massimo Filippi* Gerda Fillenbaum Christopher M. Filley John K. Fink John N. Fink Alan G. Finkel Glen R. Finney Elizabeth Fisher Marc Fisher Robert S. Fisher Annette L. Fitzpatrick Adam S. Fleisher William A. Fletcher Corey C. Ford Hans Förstl Peter A. Forsyth Norman L. Foster Nathan B. Fountain Samuel A. Frank Gary M. Franklin David Neal Franz Mark S. Freedman Roy Freeman Jacqueline French Robert P. Friedland Andrzej Friedman Deborah I. Friedman Joseph H. Friedman

Giovanni B. Frisoni Elliot Mark Frohman* Matthew P. Frosch Steven Frucht Julie Fudge Hidenao Fukuyama Cindy J. Fuller Heather J. Fullerton Karen L. Furie Joseph M. Furman* Ansgar J. Furst Yoshiaki Furukawa Ruth Gabizon Peter Gal Douglas Galasko Massimo Gallucci James E. Galvin Antonio Gambardella Pierluigi Gambetti Mary Ganguli James Y. Garbern Hector H. Garcia Paul A. Garcia Angels Garcia-Cazorla Thomas Gasser Yonas Endale Geda David S. Geldmacher Angelo Ghezzi Paul S. Giacomini Barry E. Gidal Donald L. Gilbert Gordon J. Gilbert Donald H. Gilden* David Gill Jonathan Gillard Frank Gilliam Arthur Ginsberg** Myron D. Ginsberg Gavin Giovannoni* Jonathan D. Glass Thomas H. Glick M. Maria Glymour Michel Goedert Stefan Martin Golaszewski Ralf Gold Stefan M. Gold Lynn R. Goldman Serge Goldman Joshua N. Goldstein Meredith Golomb Paul T. Golumbek Ramon Gilberto Gonzalez Howard Parker Goodkin* Andrew D. Goodman James M. Gordon Paul H. Gordon Philip B. Gorelick Kenneth C. Gorson*

4

Neurology 72

Monisha Goyal Jerome J. Graber Neill R. Graff-Radford Paul S. Graman Igor Grant William B. Grant Armin J. Grau Ari J. Green Benjamin M. Greenberg Steven A. Greenberg Paul Greene Robert S. Greenwood David Matthew Greer Robert C. Griggs Michael Gruenthal Renzo Guerrini Christian Guilleminault Ronnie Guillet Rishi Gupta Deborah Gustafson David H. Gutmann Ludwig Gutmann* Katrina A. Gwinn Mary N. Haan Mario Habek David Hackney Randi J. Hagerman Kazuhiro Haginoya Cecil David Hahn Timothy C. Hain E. Clarke Haley, Jr.* Michael Gabor Halmagyi* John J. Halperin John Hammerstad Harald Hampel Cynthia Harden Orla Hardiman C. Michel Harper Judith U. Harrer Taylor Harrison Robert G. Hart Adam L. Hartman Jonathan Hartman Anthony Simon Harvey Michael R Haupts W. Allen Hauser Sheryl R. Haut Angela Hays Peter Hedera Kenneth M. Heilman Bernhard Hemmer Victor W. Henderson Katherine Henry John W. Henson Karl Herholz Susan T. Herman David N. Herrmann Nathan Herrmann Andrew D. Hershey Linda A. Hershey

January 6, 2009

Tamara Hershey David C. Hess Daniel B. Hier Joseph James Higgins Itsuro Higuchi Argye Elizabeth Hillis William Hills David Hilton-Jones Judith A. Hinchey Rogier Q. Hintzen Michio Hirano* Lawrence J. Hirsch Mark A. Hirsch Shu Leong Ho Lisa Hobson-Webb Eric P. Hoffman David B. Hogan Eva Hogervorst Katherine Holland Julia Ulrike Holle Robert G. Holloway Gregory L. Holmes Lawrence S. Honig Martin W.I.M. Horstink Rita Horvath David A. Hovda Virginia J. Howard Chaorui Huang R.A.C. Hughes Laura K Hummers Jill Hunter Howard I. Hurtig Dominik Huster William D. Hutchison Constantino Iadecola Susan T. Iannaccone Maria Isabel Illa Karl A. Illig Noboru Imai Paul G. Ince Rivka Inzelberg David Irani Alex Iranzo Jouko I.T. Isojarvi Adrian Ivanoiu Fabio M. Iwamoto Christian Jacobi Bradley S. Jacobs Daniel H. Jacobs Steven Jacobson William J. Jagust Sebastian Jander Sophia Janjua Adil Javed Kurt A. Jellinger Joanna C. Jen Ulf R. Jensen Shafali Jeste* Gregory A. Jicha Julene K. Johnson

Keith A. Johnson Sterling C. Johnson Marilyn Jones-Gotman Lori C. Jordan Keith Anthony Josephs Tudor G. Jovin Michael J. Joyner Ralph F. Jozefowicz Burk Jubelt Vern C. Juel Csaba Juhasz Hans H. Jung Heinz Jungbluth Seppo Juvela Norman J. Kachuck Rajesh N. Kalaria David F. Kallmes Lalit Kalra* Stephen S. Kamin Henry J. Kaminski* Kousuke Kanemoto Andres M. Kanner* Ronald M. Kanner Kejal Kantarci Orhun H. Kantarci Ludwig Kappos Jaideep Kapur Jason H.T. Karlawish Carlos S. Kase Scott E. Kasner Jan Kassubek Bashar Katirji Douglas Katz Daniel I. Kaufer Mark Kaufman Anthony Kaufmann Edward M. Kaye Gordon R. Kelley Adam Kelly Kevin M. Kelly Peter G.E. Kennedy David Kent Thomas A. Kent Kevin A. Kerber Walter N. Kernan Douglas A. Kerr John F. Kerrigan Jaffar Khan Omar A. Khan Pooja Khatri Samia J. Khoury Dheeraj Khurana D. Kidd Chelsea S. Kidwell Karl D. Kieburtz Bernd C. Kieseier Ronald J. Killiany Scott Kim Christopher M. Kipps Douglas B. Kirsch

Heidi Kirsch Howard S. Kirshner Stephen J. Kish John T. Kissel Brett Kissela Steven J. Kittner Miia Kivipelto Pia Kivisakk Caroline Klein* Christopher J. Klein Pavel Klein Thomas Klopstock Alana Knudson Melissa Ko Peter J. Koehler Markus Kofler Michiaki Koga Edwin H. Kolodny Dennis Kolson Barbara S. Koppel Igor J. Koralnik Eric H. Kossoff Vladimir S. Kostic H. Kowa John W. Krakauer Joel Kramer Lars-Henrik Krarup Marilyn F. Kraus Gregory L. Krauss Rejko Kruger Lauren B. Krupp Christian Kubisch Lewis H. Kuller Dimitri Kullmann Neeraj Kumar* Sheng-Han Kuo* Tobias Kurth John F. Kurtzke Abraham Kuruvilla Patrick Kwan Jennifer M. Kwon Albert R. La Spada Daniel L. Labovitz Franco A. Laccone Pascal Laforêt Irfan Lalani William M. Landau Anthony E. Lang Bethan Lang Annette Magdalene Langer-Gould John T. Langfitt Peter Langhorne Nicholas LaRocca Hans Lassmann Larry Latour Leonore J. Launer Steven Laureys Danielle Laurin Meng Law

Ronald M. Lazar Kiwon Lee Stephen L. Lee K.L. Leenders Frank Lehmann-Horn R. John Leigh Enrique C. Leira Thomas Lempert Belinda R. Lennox Alan Jay Lerner Simmons Lessell Ronald P. Lesser James B. Leverenz Mark Lew Richard A. Lewis Ge Li David G. Lichter David S. Liebeskind Nadina B Lincoln Jon M. Lindstrom Tara T. Lineweaver Howard L. Lipton Robert P. Lisak Deborah M. Little Irene Litvan Eng H. Lo David A. Loewenstein Eric L. Logigian Giancarlo Logroscino David Loiselle Catherine Lomen-Hoerth W.T. Longstreth, Jr. Glenn Lopate Oscar L. Lopez David W. Loring Georgios Loudianos Elan D. Louis Mark A. Lovell Po-Haong Lu Fred D. Lublin Claudia Lucchinetti Roberto G. Lucchini Jose Luchsinger Eileen Luders Jan D. Lunemann Rosario Luquin Daune Lorine MacGregor Colum D. MacKinnon Arshad Majid Pauline M. Maki C.J. Malanga Kristina Malmgren David E. Mandelbaum Carol Manning Edward Manno Javier Mar Margery H. Mark Ekaterini Markopoulou William Marks Christina Marra

Connie Marras Daniel Marson Wayne Martin Ralph N. Martins Ayrton R. Massaro Jim A. Mastrianni David B. Matchar Farrah J. Mateen* Ninan Mathew Christopher J. Mathias Joseph Y. Matsumoto Brandy R. Matthews Alexander Mauskop Stephan A. Mayer Pietro Mazzoni Justin C. McArthur Andrew McCaddon John Riley McCarten Paul R. McCrory Louise D. McCullough Michael P. McDermott William M. McDonald Anne C. McKee Ian G. McKeith Martin J. McKeown Michael P. McQuillen Michel Melanson Mario F. Mendez Daniel L. Menkes Giovanni Meola Eugenio Mercuri Matthew N. Meriggioli Jose Guillermo Merino James F. Meschia Albee Messing Brett C. Meyer Mohamad Mikati Jamal A. Mikdashi Aaron E. Miller Bruce L. Miller John W. Miller Joshua W. Miller Neil R. Miller* John J. Millichap Scott Mintzer Wendy G. Mitchell Hideto Miwa J.P. Mohr Bahram Mokri Sara E. Mole Eamonn Molloy Xavier Montalban Joan Montaner Erwin B. Montgomery, Jr. Thomas J. Montine Lauren R. Moo John C. Morgan Susan Morgello Lewis B. Morgenstern Etsuro Mori

Eiji Moriyama Elena Moro Karen E. Morrison Leslie Morrison Solomon L. Moshe Thomas H. Mosley Stewart H. Mostofsky Dwight E. Moulin M. Maral Mouradian* Susanne Mueller Keith W. Muir Ulrich M¨uller Rajkumar Munian Govindan David G. Munoz Daniel L. Murman Anne M. Murray Gary J. Myers Richard H. Myers Stephen E. Nadeau Margaret A. Naeser Sakkubai R. Naidu Takashi Nakajima Tatsufumi Nakamura Nobukazu Nakasato Avindra Nath Bart Nathan Karin B. Nelson Edwin M. Nemoto Jayne Ness Peter J. Nestor Jeff L. Neul Nancy J. Newman David E. Newman-Toker Thanh N. Nguyen David J. Nicholl Garth A. Nicholson MingMing Ning Ichizo Nishino Michael J. Noetzel Yoshiko Nomura Douglas R. Nordli Gustavo A. Nores Kathryn N. North Jonathan A. Norton Olga Noskin Katia Noyes Marc Nuwer David L. Nyenhuis Thomas O. Obisesan Paul O’Connor* Joel J. Oger Adesola Ogunniyi Unsong Oh Kinji Ohno Jeffrey G. Ojemann Jorge Oksenberg Anders Oldfors John M. Olichney Montse Olive Neurology 72

William G. Ondo Brian P. O’Neill Stephen M. Oppenheimer* Richard Orrell Roger Oskvig Padraig O’Suilleabhain Brian R. Ott Ryan Taylor Overman* Ozcan Ozdemir Laurie J. Ozelius Andrew R. Pachner* Alison M. Pack Luca Padua Rajesh Pahwa Massimo Pandolfo Hillel Panitch Leonardo Pantoni Gabriel Pardo Alvaro Pascual-Leone Maria A. Pastor Pau Pastor Marc C. Patterson Shanna K. Patterson Jane S. Paulsen Steven G. Pavlakis Valory N. Pavlik David Pearce Phillip L. Pearl Guerry M. Peavy Otto Pedraza John M. Pellock Wendy Larson Peltier Page B. Pennell Daniela Perani Alan K. Percy George Perry Ronald C. Petersen Bradley S. Peterson Alessandro Pezzini Adolf Pfefferbaum Michel Philippart Lawrence H. Phillips, II Giovanni Piedimonte Istvan Pirko Sean J. Pittock* Gordon T. Plant Samuel Pleasure Roberto Pola Michael Polkey Michael Polydefkis Marcus Ponce de Leon John D. Port Holly B. Posner Chris Power William J. Powers Shyam Prabhakaran Michael R. Pranzatelli Sashank Prasad* Cate Price

January 6, 2009

5

Richard W. Price James W. Prichard Michael Privitera Calin I. Prodan J. Javier Provencio Amy A. Pruitt William E.M. PrysePhillips Louis J. Ptacek Seth L. Pullman Gail Pyne-Geithman Angelo Quartarone Aldo Quattrone Maryka Quik Joseph Quinn Gil Dan Rabinovici Peter V. Rabins Alejandro A. Rabinstein* Brad A. Racette Michael K. Racke* Alexander H. Rajput Ali H. Rajput Nabih M. Ramadan Isabelle Rapin Alan M. Rapoport Olivier Rascol Katya Rascovsky Bernd Rautenstrauss Saif S.M. Razvi Anthony T. Reder Bruce R. Reed Stephen G. Reich Mary M. Reilly Matthias Reinhard Christiane Reitz Norman R. Relkin David Rempe Susan M. Resnick Lucas Restrepo Enzo Ricci Nancy D. Richert Eric K. Richfield Hugh Rickards Keith R. Ridel* Olaf Riess Garrett Riggs Fred Rincon Juha O. Rinne Alan Rio Anthony L. Ritaccio James J. Riviello Matthew Rizzo E. Steve Roach T.G. Robinson Jessica Robinson-Papp Patricia Rodier Robert L. Rodnitzky Joseph Rogers Gustavo C. Roman Serge A.R.B. Rombouts

Jose Rafael Romero Michael Ronthal Raymond P. Roos Jonathan Rosand John W. Rose Howard J. Rosen Gary A. Rosenberg Adam Rosenblatt Myrna R. Rosenfeld Elizabeth Ross Owen A. Ross Janet Rucker Richard A. Rudick Stephan J R¨uegg Robert L. Ruff Sean D. Ruland Tatjana Rundek Hans-J¨urgen Rupprecht Barry S. Russman Paul Rutecki Ralph L. Sacco Perminder S. Sachdev Saud A Sadiq Dessa Sadovnick Murray G. Sagsveen Gerard Said* Stephen P. Salloway David P. Salmon Philipp Georg Sämann Martin A. Samuels Josemir W. Sander Donald B. Sanders Paola Sandroni Raman Sankar Lauren Hachmann Sansing Filippo M. Santorelli David S. Saperstein Gustavo Saposnik Harvey B. Sarnat* Justin A. Sattin Nikolaos Scarmeas Elio Scarpini Wolf R. Schäbitz Mark B. Schapiro Jeremiah Scharf Douglas W. Scharre Ingrid E. Scheffer Peter D. Schellinger Carlos H. Schenck Ann I. Scher Wouter Ingmar Schievink David Schiff* Raphael Schiffmann Bradley L. Schlaggar Gottfried Schlaug James Schmidley Frederick A. Schmitt Heike I. Schmolck Michal Schnaider Beeri

6

Neurology 72

Julie A. Schneider Susanne A. Schneider S. Clifford Schold Anette Schrag Norbert Schuff Hermann Christian Schumacher Stefan Schwarz Todd J. Schwedt Steven R. Schwid* Burton L. Scott Thomas F. Scott Meghan M. Searl Oliver L. Sedlaczek Alan Z. Segal Benjamin M. Segal Scott Seidman Rudiger J. Seitz Elizabeth Sekul Duygu Selcen John B. Selhorst Magdy Selim Warren R. Selman Linda M. Selwa Andrea Semplicini Klaus Seppi Sudha Seshadri Lee Seung-Koo Caroline A. Sewry Saad Shafqat Kathleen M. Shannon Leroy R. Sharer Frank R. Sharp James A. Sharpe Jeremy M. Shefner Elliott Sherr Raj D. Sheth Michael I. Shevell Holly Shill Robert K. Shin Ashfaq Shuaib Lisa M. Shulman Michael E. Shy Teepu Siddique John J. Sidtis M. Siebler Hartwig Roman Siebner Bruce Sigsbee Cathy A. Sila Stephen D. Silberstein Brian Silver Isaac E. Silverman Faye Silverstein Gabriella Silvestri Zachary Simmons Jack H. Simon David M. Simpson Aneesh B. Singhal Andrew B. Singleton

January 6, 2009

Joseph I. Sirven Clark Slater Andrew Slivka, Jr. Brent J. Small A. Gordon Smith Benn E. Smith** Charles D. Smith Glenn E. Smith Stephen A. Smith Barry J. Snow Elson L. So Norman K. So Yuen So Raymond A. Sobel Tomás Sobrino Hilkka Soininen Nina Solenski G.G. Somjen Sarah Song* Per Sorensen Eric J. Sorenson* J.D. Speelman Anne Spurkland Erik K. St. Louis* Mark Stacy James M. Stankiewicz Bruno Stankoff Steven Stasheff Israel Steiner Barney J. Stern Suzanne Stevens Jonathan Stewart Robert Stewart Christopher J. Stodgell A. Jon Stoessl Lael Anne Stone Brigitte StorchHagenlocher Michael Strupp* Olaf Stuve* Jose I. Suarez* Joohee Sul Gene Sung Thomas P. Sutula Clive Svendsen Jerry W. Swanson Richard H. Swartz Michael Swash* Robert A. Sweet Russell H. Swerdlow* Minoru Tagawa Michele Tagliati Hitoshi Takahashi Ryosuke Takahashi David Tanne Mark Tarnopolsky Turgut Tatlisumak William O. Tatum, IV Antonio L. Teixeira

Jose Francisco TellezZenteno Richard B. Tenser Kenshi Terajima Karel TerBrugge William H. Theodore Vincent N. Thijs Liu Lin Thio Alan J. Thompson Charles A. Thornton Guy E. Thwaites Pentti J. Tienari Mary C. Tierney Gretchen E. Tietjen Maja Tippmann-Peikert Haluk Topaloglu Michel T. Torbey James C. Torner Amytis Towfighi Klaus V. Toyka Bryan J. Traynor Claudia Trenkwalder William J. Triggs Alexander I. Tröster Jack W. Tsao Georgios Tsivgoulis Stanley Tuhrim Paul Tuite William R. Tyor Ergun Y.Uc Shinichiro Uchiyama Bjarne Udd Joon H. Uhm Nachum Vaisman Christine Van Broeckhoven Martin J. van den Bent Leonard H. van den Berg Nadine A.M.E. van der Beek Marjo S. van der Knaap Ludo W. van der Pol J. Marc C. van Dijk Jay A. Van Gerpen Gregory P. Van Stavern John C. van Swieten Edward Vates Shannon L. Venance Joe Verghese Steven Vernino Meike W. Vernooij Matti Viitanen Carles Vilarino-Guell Angela Vincent John Vissing Jerrold L. Vitek Jens Volkmann Raymond D. Voltz Kerstin von Plessen Jean Paul Vonsattel

Rhonda R. Voskuhl Francine J. Vriesendorp Salina P. Waddy Virginia Wadley Lars-Olof Wahlund Mark F. Walker Michael Wall Mitchell T. Wallin Annabel Kim Wang Ching H. Wang Jian Wang Lilly Wang Julia V. Wanschitz Steven Warach Joanna M. Wardlaw Tom T. Warner

Craig Watson James Watson John D.G. Watson Miriam T. Weber Lawrence R. Wechsler Louis H. Weimer William J. Weiner Brian G. Weinshenker Bianca WeinstockGuttman Marc G. Weisskopf Kathle A. Welsh-Bohmer Patrick Y. Wen Shawn K. Westaway Charles White Rachel Whitmer

Jennifer L. Whitwell Eelco F.M. Wijdicks* Linda S. Williams Michael A. Williams Hugh J. Willison Robert S. Wilson Melodie Rose Winawer Dean M. Wingerchuk Max Wintermark Karin Wirdefeldt Thomas Wisniewski Max Wiznitzer John H.J. Wokke Nicole I. Wolf Philip A. Wolf Gil I. Wolfe

Jerry S. Wolinsky Ka Sing Wong Tony Wong Virginia C.N. Wong Daniel Woo Steven Paul Woods Fred G. Wooten Gregory A. Worrell Clinton B. Wright Zbigniew Wszolek Ona Wu Ruey-Meei Wu Yih-Ru Wu Dongrong Xu Hiroshi Yao Ann Yeh

Howard Yonas George K. York Michele York Nobuhiro Yuki* John P. Zajicek Peter P. Zandi Nathan Zasler Mayana Zatz Allyson Zazulia Adam Z.J. Zeman John M. Zempel Lin Zhang Justin A. Zivin Douglas W. Zochodne George S. Zubenko

DISCLOSURE John H. Noseworthy, MD, FAAN, receives an honorarium from AAN as Editor in Chief of Neurology. Robert A. Gross, MD, PhD, FAAN, has received research funding from the Department of the Army, Ortho-McNeil, and UCBPharma. He is supported for educational endeavors from the University of Rochester Medical Center’s Clinical and Translational Science Award from the NIH. Dr. Gross has conducted clinical trials over the past 5 years funded by GlaxoSmithKline, UCB, Ortho-McNeil, Pfizer, and Marinus. Dr. Gross has served on the speakers’ bureaus for Abbott, UCB, Ortho-McNeil, and GlaxoSmithKline and has received consultant fees from Harris Interactive. Dr. Gross has received honoraria from Ortho-McNeil, UCB, Abbott Laboratories, and GlaxoSmithKline. He receives an honorarium as Deputy Editor of Neurology. Andrew G. Engel, MD, FAAN, receives research funding from the NIH and the Muscular Dystrophy Association. Dr. Engel receives royalties from McGraw-Hill for editing the 3rd edition of Myology and received travel funding from Pfizer for a meeting held in Spain. Dr. Engel received an honorarium for an invited lecture for the Child Neurology Society and receives an honorarium as Associate Editor of Neurology. Karen C. Johnston, MD, MSc, has received research funding from the NIH (three grants); consults for Diffusion Pharmaceutical, Inc., and Remedy Pharmaceutical; is on the Advisory Board for Remedy Pharmaceutical; receives royalties from Up to Date; and received honoraria from Remedy Pharmaceutical, BI, AUPN/ANA/NINDS, and NINDS study section, and receives an honorarium as Associate Editor of Neurology. David S. Knopman, MD, has received research funding from the NIH (four grants). Dr. Knopman served on the Data Safety Monitoring Board for Sanotif-Aventis. Dr. Knopman’s institution receives research support from Elan Pharmaceuticals (no personal compensation). Dr. Knopman received research support from Forest Laboratories (no personal compensation). In the past 2 years, he received honoraria from the University of Kentucky, St. Johns Medical Center, Jackson, WY, and the South Dakota Alzheimer Association and receives an honorarium as Associate Editor of Neurology. Jonathan W. Mink, MD, PhD, has received research support from NIH/ NINDS. Dr. Mink serves on the Board of Scientific Counselors, NINDS.

Dr. Mink has received travel funding from the Tourette Syndrome Association. He is a member of the Editorial Boards of Pediatric Neurology and the Journal of Child Neurology. Dr. Mink has received book royalties from Lippincott Williams & Wilkins. Dr. Mink has received honoraria from the Tourette Syndrome Association and receives an honorarium as Associate Editor of Neurology. Richard M. Ransohoff, MD, conducts research supported by the NIH and the National MS Society, with the recent support from the Dana Foundation, the Robert S. Packard Foundation and the Nancy Davis Center without Walls. Dr. Ransohoff has recently received fees for preclinical consulting from Amgen, Astra-Zeneca, Biogen-Idec, Boehringer Ingelheim, GlaxoSmithKline Shanghai, Merck, Merck-Serono, Merrimack, Millennium, Momenta, Novartis, Novimmune, Pharmacopeia, Sanofi-Aventis, ScheringPlough and Xanthus. Dr. Ransohoff serves on the Chemocentryx Scientific Advisory Board and the Vertex Scientific Advisory Board-Immunology/ Inflammation Sub-group. He receives an honorarium as Associate Editor of Neurology. Ryan J. Uitti, MD, FAAN, has received research funding from the NIH, PARRF, and Advanced Neuromodulation Systems, Inc. Dr. Uitti has served as a Continuing Medical Educator for the AAN. Dr. Uitti’s institution has received annual royalties from the licensing of the technology related to PARK8/LRRK2 greater than the federal threshold for significant financial interest; Dr. Uitti has not received any royalties. Dr. Uitti has received honoraria from Callosal Connection and receives an honorarium as Associate Editor of Neurology. Bradford B. Worrall, MD, MSc, has received research funding from NIH (six grants). He serves as an outcomes adjudicator for the NHLBI for AREDS2 and as an ad hoc reviewer for the NIH and Veterans Administration study sections. Dr. Worrall received several honoraria for serving as faculty and/or director for courses at the AAN annual meetings and an honorarium for speaking for the Operation Stroke program (AHA/ASA funded) at Fairfax Inova Hospital. Dr. Worrall is on the Editorial Boards of Neurology and Seminars in Neurology. Dr. Worrall received nominal royalties for serving as a chapter author for Merritt’s Neurology and receives an honorarium as Associate Editor of Neurology.

Neurology 72

January 6, 2009

7

EDITORIAL

Levels of evidence Taking Neurology® to the next level

Robert A. Gross, MD, PhD Karen C. Johnston, MD, MSc

Address correspondence and reprint requests to Dr. Robert A. Gross, University of Rochester, Department of Neurology, 601 Elmwood Avenue Box 673, Rochester, NY 14642-0001 [email protected]. edu

Neurology® 2009;72:8–10

When you pick up an issue of Neurology® and scan its contents, how do you decide what to read? And how do you decide if what you read should change your clinical practice? The value of a scientific study can be assessed by a variety of objective and subjective measures and its value will depend on your perspective. Do you view the results as a researcher or as a practicing neurologist seeking the best evidence on which to make clinical decisions? Readers will naturally assess whether the article’s focus aligns with their interests, either investigative or care-based; whether the findings answer a question relevant to those pursuits; and whether the results are robust enough to serve as a definitive basis for informing their work. In short, readers will be assessing the strength of evidence presented. We might all agree in principle with the notion that the practice of medicine ought to be based on evidence; yet there are situations for which there is little to no evidence, and others for which the evidence is of varying strength. A simple standardized system that can organize the evidence would make such an assessment easier. At Neurology, we are dedicated to bringing our readers the most relevant and sound scientific research, focusing largely although not exclusively on human subjects. We also publish Practice Parameters and Clinical Guidelines that assess the primary literature and allow readers to see a summary of the strengths and limitations of those studies. In turn, those analyses inform a consensus regarding recommendations for clinical care. In a previous issue of Neurology, two special articles by Gronseth and French1,2 described the issues that arise in analyzing the primary literature in order to make clinical care recommendations. In one article, they discussed the

nature of Practice Parameters and Guidelines, how they are generated and what they can and cannot tell us. The accompanying article reviewed levels of evidence (LOE), the metric by which the strength of studies can be assessed; the strength of the LOE determines the solidity of the evidence base for clinical practice. Though such Practice Parameters and Guideline statements routinely describe levels of evidence, most work published in Neurology is not formally assessed for strength of evidence prior to publication. As an additional service to our readers, we will begin publishing the level of evidence for therapeutic clinical trials. We believe that such information will inform the reader in a standardized way and facilitate decisions regarding integration of the information into clinical practice. This is part of a larger goal, involving the Quality and Standards subcommittee (QSS) of the American Academy of Neurology, to assess comprehensively the evidence in our field so that clinical decision-making is increasingly evidence-based and that the limits of the evidence are made clear. Beginning in early 2009, our readers will find that every therapeutic clinical trial published in Neurology will have a notation of the level of evidence, according to the criteria developed by the QSS (see table 1). After January 14, 2009, the journal will require that the authors assign a level of evidence for an identified clinical question, but the assigned level of evidence will be adjudicated by an independent team prior to publication. Readers will benefit by being able to determine immediately the robustness of the evidence presented in our journal. As shown in table 1, reproduced from the first cited article, the evidence will be classified into one of

From the Department of Neurology (R.A.G.), University of Rochester, NY; and Department of Neurology (K.C.J.), University of Virginia, Charlottesville. Disclosure: Robert A. Gross, MD, PhD, FAAN, has received research funding from the Department of the Army, Ortho-McNeil, and UCBPharma. He is supported for educational endeavors from the University of Rochester Medical Center’s Clinical and Translational Science Award from the NIH. Dr. Gross has conducted clinical trials over the past 5 years funded by GlaxoSmithKline, UCB, Ortho-McNeil, Pfizer, and Marinus. Dr. Gross has served on the speakers’ bureaus for Abbott, UCB, Ortho-McNeil, and GlaxoSmithKline and has received consultant fees from Harris Interactive. Dr. Gross has received honoraria from Ortho-McNeil, UCB, Abbott Laboratories, and GlaxoSmithKline. He receives an honorarium as Deputy Editor of Neurology®. Karen C. Johnston, MD, MSc, has received research funding from the NIH (three grants); consults for Diffusion Pharmaceutical, Inc. and Remedy Pharmaceutical; is on the Advisory Board for Remedy Pharmaceutical; receives royalties from Up to Date; and received honoraria from Remedy Pharmaceutical, BI, AUPN/ANA/NINDS, and NINDS study section. She receives honoraria as an Associate Editor of Neurology®. 8

Copyright © 2009 by AAN Enterprises, Inc.

Table 1

American Academy of Neurology classification scheme requirements for therapeutic questions1

Class I. A randomized, controlled clinical trial of the intervention of interest with masked or objective outcome assessment, in a representative population. Relevant baseline characteristics are presented and substantially equivalent among treatment groups or there is appropriate statistical adjustment for differences. The following are also required: a. Concealed allocation b. Primary outcome(s) clearly defined c. Exclusion/inclusion criteria clearly defined d. Adequate accounting for dropouts (with at least 80% of enrolled subjects completing the study) and crossovers with numbers sufficiently low to have minimal potential for bias e. For noninferiority or equivalence trials claiming to prove efficacy for one or both drugs, the following are also required* 1. The standard treatment used in the study is substantially similar to that used in previous studies establishing efficacy of the standard treatment (e.g., for a drug, the mode of administration, dose, and dosage adjustments are similar to those previously shown to be effective). 2. The inclusion and exclusion criteria for patient selection and the outcomes of patients on the standard treatment are substantially equivalent to those of previous studies establishing efficacy of the standard treatment. 3. The interpretation of the results of the study is based on an observed-cases analysis. Class II. A randomized, controlled clinical trial of the intervention of interest in a representative population with masked or objective outcome assessment that lacks one criterion a– e Class I, above, or a prospective matched cohort study with masked or objective outcome assessment in a representative population that meets b– e Class I, above. Relevant baseline characteristics are presented and substantially equivalent among treatment groups or there is appropriate statistical adjustment for differences. Class III. All other controlled trials (including well-defined natural history controls or patients serving as their own controls) in a representative population, where outcome is independently assessed, or independently derived by objective outcome measurements. Class IV. Studies not meeting Class I, II, or III criteria including consensus or expert opinion.

Reprinted from French and Gronseth.1 *Note that numbers 1-3 in Class Ie are required for Class II in equivalence trials. If any one of the three is missing, the class is automatically downgraded to a Class III.

four classes (I–IV), with randomized blinded controlled trials representing the strongest, Class I, evidence, and clinical observations of the type presented in a case study representing the least robust, Class IV, evidence. It is important to realize that these levels do not imply that Class III or IV science is flawed, but rather, it is an assessment of the strength of the scientific evidence for making therapeutic decisions. Finally and equally important to the strength of the evidence is knowledge of the primary clinical question the study was designed to answer. Secondary or post hoc outcomes for studies will usually provide weaker evidence. Another advantage of providing standardized LOE for articles is that those levels can be translated into classes of recommendations for clinical care (table 2, reproduced from the second cited Table 2

article). In this way, readers can, by seeing the LOE and noting the question(s) to which the data apply, assess whether the findings can or should influence their practice. This does not replace Practice Parameters or Guidelines, which assess recommendations based on a survey of all the available literature on a single topic and thereby provide stronger recommendations. As an additional benefit, a method of systematically capturing the evidence for a given topic will be initiated. Each article with its level of evidence will be logged in a table with all the past articles reviewed for Practice Parameters and Clinical Guidelines. This will allow interested persons to review the literature in a given area and comprehensively assess the strength of evidence relevant to a particular clinical topic. This archive of data will be available for the

American Academy of Neurology classification of recommendations

A ⴝ Established as effective, ineffective, or harmful (or established as useful/predictive or not useful/predictive) for the given condition in the specified population. (Level A rating requires at least two consistent Class I studies.)* B ⴝ Probably effective, ineffective, or harmful (or probably useful/predictive or not useful/predictive) for the given condition in the specified population. (Level B rating requires at least one Class I study or two consistent Class II studies.) C ⴝ Possibly effective, ineffective, or harmful (or possibly useful/predictive or not useful/predictive) for the given condition in the specified population. (Level C rating requires at least one Class II study or two consistent Class III studies.) U ⴝ Data inadequate or conflicting; given current knowledge, treatment (test, predictor) is unproven.

Reprinted from Gronseth and French.2 *In exceptional cases, one convincing Class I study may suffice for an “A” recommendation if 1) all criteria are met, 2) the magnitude of effect is large (relative rate improved outcome ⬎ 5 and the lower limit of the confidence interval is ⬎ 2). Neurology 72

January 6, 2009

9

Neurology readership even prior to the development of Practice Parameters or Clinical Guidelines. We believe that organizing the evidence in this way will improve our readership’s ability to efficiently assess the evidence and use it appropriately for clinical decision making. Few journals publish levels of evidence with their articles. This important addition to Neurology is another facet of our dedication to educating our readership about advances in our field. Further, it represents a leap ahead in providing our readers value added to the already high quality of published articles. Our hope is that this will prompt greater discernment among both authors and readers regarding the strengths and limitations of published work and thereby spur an increase in the overall quality of work submitted to Neurology. Our initial effort will focus on therapeutic trials because they are among the most important and

relevant studies we publish and they inform clinical decision-making and design of future research. Each annotation will include the LOE and a statement of the clinical question for which the result is relevant. Diagnostic studies and prospective observational studies will be annotated next. Eventually, we plan to provide annotations for every research article published in Neurology. In this way, Neurology will remain as the go-to source for advances in our field as well as a comprehensive source of evidence for major clinical questions.

REFERENCES 1. French J, Gronseth G. Lost in a jungle of evidence: we need a compass. Neurology 2008;71:1634–1638. 2. Gronseth G, French J. Practice parameters and technology assessments: what they are, what they are not, and why you should care. Neurology 2008;71:1639–1643.

Editor’s Note: In future issues of the journal, the tables reprinted in this article will be represented in available journal space by the graphics shown below. Papers evaluated for classification of evidence and guidelines with clinical recommendations will be designated with corresponding icons on the cover and in the tables of contents.

10

Neurology 72

January 6, 2009

EDITORIAL

The need for biomarkers in amyotrophic lateral sclerosis drug development

Kathryn R. Wagner, MD, PhD

Address correspondence and reprint requests to Dr. Kathryn R. Wagner, Departments of Neurology and Neuroscience, Johns Hopkins University, 600 N. Wolfe St., Meyer 5-119, Baltimore, MD 21287 [email protected]

Neurology® 2009;72:11–12

Recent contributions to Neurology® have highlighted the disappointing lack of demonstrated efficacy of novel therapeutic approaches to amyotrophic lateral sclerosis (ALS).1–3 Failure of translation, from promising preclinical studies to positive clinical trials, has raised concerns about the relevance of animal models and about clinical trial design. Development of novel therapeutics in ALS is also severely hampered by the lack of a biologic marker (biomarker) defined as “a characteristic that is objectively measured and evaluated as an indicator of normal biologic processes, pathogenic processes, or pharmacologic response to a therapeutic intervention.”4 The importance of biomarkers in therapy development is underscored by the fact that for diseases in which good biomarkers exist, such as glycosylated hemoglobin for diabetes and serum lipid profiles for atherosclerotic coronary artery disease, there are multiple approved drugs, while for diseases in which there are no good biomarkers, such as Alzheimer disease, muscular dystrophy, and ALS, there are very few therapeutic options. Biomarkers have been proposed for ALS, although none are currently incorporated into clinical use or clinical trial design.5– 8 In this issue of Neurology, Mitchell and coworkers9 propose a new panel of biomarkers focused on mediators of inflammation, from the CSF of patients with ALS. Good biomarkers for ALS would fulfill one or more essential functions. Currently, there is no specific diagnostic test for ALS, which is determined by a clinical history and examination supported by laboratory and electrophysiology data. A disease biomarker would enable earlier diagnosis, reducing the amount of time and testing prior to diagnosis. In addition, future therapies will presumably be more efficacious early in the course of the disease, thus necessitating development of a sensitive disease biomarker. Clinical trials in ALS have typically followed surrogate outcome measures such as muscle strength, which requires large cohorts and long treatment periods. A surrogate

outcome measure biomarker would potentially enable shorter and smaller proof of principal trials in ALS, allowing the field to quickly assess multiple approaches before investing resources in larger trials. In addition, since the inciting events of ALS are largely unknown, determining a molecular signature of disease may provide clues to pathogenesis. In the study by Mitchell et al.,9 the authors report a distinct profile of proteins from the CSF of subjects with ALS compared to neurologic disease controls. Considering a possible pathogenesis of excessive neuroinflammation or aberrant growth factor regulation in ALS, the authors performed multiplex analysis on CSF from 41 subjects with ALS and 33 neurologic disease controls using the Bio-Plex Human 27-plex panel of cytokine and growth factors (Bio-Rad, Hercules, CA). This analysis identified statistically significant differences in the levels of 13 proteins present in the CSF. Using five factors with the most significant p values, the authors propose a panel including IL-10, IL-6, GM-CSF, IL-2, and IL-15 which demonstrated 89.2% accuracy, 87.5% sensitivity, and 91.2% specificity in identifying patients with ALS within this study. Of these factors, only IL-6 has previously been suggested for other biomarker panels of ALS.10 The neurosecretory protein VEGF has been proposed as a potential ALS biomarker in previous studies including that by Pasinetti and colleagues, which used proteomics technology to identify an ALS biomarker panel of three proteins from the CSF.6,8 VEGF was also found in the current study to be significantly higher in the CSF of subjects with ALS compared to controls (p ⫽ 0.007) but was not among the most significantly altered and therefore not included in the biomarker panel. The CSF is an attractive potential source for ALS biomarkers due to its anatomic proximity to motor neurons. Although the CSF is not routinely used in the clinical diagnosis of ALS, it certainly could be if a powerful test were available. The proposed biomarker panel by Mitchell et al. does not yet appear to be

See page 14 From the Departments of Neurology and Neuroscience, Johns Hopkins University, Baltimore, MD. Supported by the NIH (U54052646) and the Muscular Dystrophy Association. Disclosure: The author reports no disclosures. Copyright © 2009 by AAN Enterprises, Inc.

11

such a powerful test with less accuracy, sensitivity, and specificity than a previously proposed panel by Pasinetti et al.6 Future studies with much larger numbers of patients and neurologic disease controls, including other motor neuron diseases, will be crucial for establishing the utility of Mitchell et al. ’s panel of 5. The panel will need to be validated in another cross-sectional study with a separate population, and in a longitudinal study to determine if the panel can be used to measure disease progression. An ALS biomarker panel, developed from the five cytokines proposed by Mitchell and colleagues, the three protein panel proposed by Pasinetti et al., VEGF, or perhaps a combination derived from the above studies, will be critical for future clinical trials and drug development for ALS. It is encouraging for the field that a validation study of ALS biomarkers is currently recruiting subjects (clinicaltrials.gov; NCT00677768) and that additional candidate proteins continue to be proposed such as in this issue. With biomarkers as molecular signatures of disease, we can reasonably expect more proof of principal trials, more efficient and successful drug development, and ultimately, turn ALS into a manageable disease such as diabetes and coronary artery disease. REFERENCES 1. Harel NY, Sorenson EJ, Miller RG, et al. What is next in ALS clinical trials? Neurology 2008;70:1365–1366.

12

Neurology 72

January 6, 2009

2. Hoke A, Sorenson EJ, Miller RG, et al. What is next in ALS clinical trials? Neurology 2008;70:1366–1367. 3. Sorenson EJ. What is next in ALS clinical trials? Neurology 2007;69:719–720. 4. Group BDW. Biomarkers and surrogate endpoints: preferred definitions and conceptual framework. Clin Pharmacol Ther 2001;69:89–95. 5. Gruzman A, Wood WL, Alpert E, et al. Common molecular signature in SOD1 for both sporadic and familial amyotrophic lateral sclerosis. Proc Natl Acad Sci USA 2007;104:12524–12529. 6. Pasinetti GM, Ungar LH, Lange DJ, et al. Identification of potential CSF biomarkers in ALS. Neurology 2006;66: 1218–1222. 7. Ranganathan S, Williams E, Ganchev P, et al. Proteomic profiling of cerebrospinal fluid identifies biomarkers for amyotrophic lateral sclerosis. J Neurochem 2005;95. 8. Zhao Z, Lange DJ, Ho L, et al. VGF is a novel biomarker associated with muscle weakness in amyotrophic lateral sclerosis (ALS), with a potential role in disease pathogenesis. Int J Med Sci 2008;5:92–99. 9. Mitchell RM, Freeman WM, Randazzo WT, et al. A CSF biomarker panel for identification of patients with amyotrophic lateral sclerosis. Neurology 2009;72:14– 19. 10. Sekizawa T, Openshaw H, Ohbo K, Sugamura K, Itoyama Y, Niland JC. Cerebrospinal fluid interleukin 6 in amyotrophic lateral sclerosis: immunological parameter and comparison with inflammatory and noninflammatory central nervous system disease. J Neurol Sci 1998;154:194–199.

EDITORIAL

A new disease mimicking Refsum syndrome

Thomas D. Bird, MD

Address correspondence and reprint requests to Dr. Thomas D. Bird, VA Puget Sound Health Care System, University of Washington, Seattle, WA 98108 [email protected]

Neurology® 2009;72:13

In this issue of Neurology®, Fiskerstrand et al.1 describe a novel family with a “Refsum-like disorder.” In one of those satisfying quirks of timing, it was precisely 25 years ago that another article appeared in Neurology by Refsum and colleagues describing the successful dietary treatment of a patient with Refsum disease.2 Sigvald Refsum (1907–1991), Norway’s best known neurologist, described the disease that bears his name in 1945/1946 and called it “heredopathia atactica polyneuritiformis.”3 He went on to be Chair of the Neurology Department at Oslo from 1954 to 1978. The disease associated with his name is an autosomal recessive disorder usually presenting with night blindness followed by various combinations of retinitis pigmentosa, sensory/motor demyelinating neuropathy, deafness, ataxia, cataract, cardiomyopathy, and ichthyosis.4 No single person has all these characteristics. The disease is most often (90%) caused by mutations in the PHYH gene that encodes phytanoyl co-A hydroxylase resulting in defective alpha oxidation of phytanic acid. This defect leads to increased plasma phytanic acid and can be successfully treated by the early dietary restriction of phytanic acid containing foods (fish, beef, lamb, dairy products) or plasma exchange. In less than 10% of the patients there is a mutation in the PEX7 gene encoding the peroxisome associated PTS2 receptor and also leading to increased plasma phytanic acid. (The AMACAR syndrome [␣-methylacyl-CoA racemase deficiency] also has some clinical and biochemical overlap with Refsum disease.) The single Norwegian family reported by Fiskerstrand and colleagues has the autosomal recessive inheritance of a syndrome associated with pigment retinopathy, peripheral neuropathy, hearing loss, ataxia,

and cataract. Thus the similarities with Refsum disease. However, unlike Refsum disease, this new family has spasticity, no cardiomyopathy, no increase in plasma phytanic acid, and normal alpha oxidation enzymatic activity. Furthermore, this disease shows genetic linkage to chromosome 20 (the PHYH gene is on chromosome 10 and PEX7 is on chromosome 6) although the gene and its encoded protein are yet to be discovered. This new family and its unique disease are important for three reasons. First, it will now be in the differential diagnosis of patients appearing similar to Refsum disease but having no defect in phytanic acid metabolism. Second, the eventual discovery of the genetic defect in this new disorder will provide additional insights into the pathogenesis of diseases affecting the retina and peripheral and central nervous systems. Third, this is yet another example emphasizing the tremendous heterogeneity in genetic diseases of the nervous system and the list continues to grow. It is simply not true that most genes causing hereditary diseases of the nervous system have now been discovered. To paraphrase Mark Twain, the claim that we have nearly reached the end of identifying all genes causing Menedelian diseases of the nervous system is greatly exaggerated. REFERENCES 1. Fiskerstrand T, Knappskog P, Majewski J, Wanders RJ, Bowman H, Bindoff LA. A novel Refsum-like disorder that maps to chromosome 20. Neurology 2009;72:20–27. 2. Djupesland G, Flottorp G, Refsum S. Phytanic acid storage disease: hearing maintained after 15 years of dietary treatment. Neurology 1983;33:237–240. 3. Beighton P, Beighton G. The Man Behind the Syndrome. Berlin: Springer-Verlag; 1986:142–143. 4. Wanders RJA, Waterham HR, Leroy BP. Genereviews: Refsum disease (2006). Available at: http://www.genetests. org. Accessed July 21, 2008.

See page 20 e-Pub ahead of print on November 12, 2008, at www.neurology.org. From the VA Puget Sound Health Care System, University of Washington, Seattle. Disclosure: Dr. Bird receives licensing fees from Athena Diagnostics, Inc. Copyright © 2009 by AAN Enterprises, Inc.

13

ARTICLES

A CSF biomarker panel for identification of patients with amyotrophic lateral sclerosis

R.M. Mitchell, BS W.M. Freeman, PhD W.T. Randazzo, BS H.E. Stephens, MA J.L. Beard, PhD Z. Simmons, MD J.R. Connor, PhD

Address correspondence and reprint requests to Dr. James R. Connor, Department of Neurosurgery, H110, The Pennsylvania State University College of Medicine, 500 University Drive (H110), Hershey, PA 17033-0850 [email protected]

ABSTRACT

Background: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease with complicated pathogenesis that poses challenges with respect to diagnosis and monitoring of disease progression.

Objectives: To identify a biomarker panel that elucidates ALS disease pathogenesis, distinguishes patients with ALS from neurologic disease controls, and correlates with ALS disease characteristics, and to determine the effect of HFE gene variants, a potential risk factor for sporadic ALS, on the biomarker profile.

Methods: We obtained CSF samples by lumbar puncture from 41 patients with ALS and 33 neurologic disease controls. All patients were genotyped for HFE polymorphisms. We performed a multiplex cytokine and growth factor analysis and immunoassays for iron-related analytes. Classification statistics were generated using a support vector machine algorithm.

Results: The groups of patients with ALS and neurologic disease controls were each associated with distinct profiles of biomarkers. Fourteen biomarkers differed between patients with ALS and the control group. The five proteins with the lowest p values differentiated patients with ALS from controls with 89.2% accuracy, 87.5% sensitivity, and 91.2% specificity. Expression of IL-8 was higher in those patients with lower levels of physical function. Expression of ␤2-microglobulin was higher in subjects carrying an H63D HFE allele, while expression of several markers was higher in subjects carrying a C282Y HFE allele.

Conclusions: A CSF inflammatory profile associated with amyotrophic lateral sclerosis (ALS) pathogenesis may distinguish patients with ALS from neurologic disease controls, and may serve as a biomarker panel to aid in the diagnosis of ALS pending further validation. Some of these biomarkers differ by HFE genotype. Neurology® 2009;72:14–19 GLOSSARY ALS ⫽ amyotrophic lateral sclerosis; ALSFRS-R ⫽ ALS Functional Rating Scale-revised; BSA ⫽ bovine serum albumin; FGF ⫽ fibroblast growth factor; G-CSF ⫽ granulocyte colony stimulating factor; GM-CSF ⫽ granulocyte-monocyte colony stimulating factor; IFN ⫽ interferon; IL ⫽ interleukin; MCP ⫽ monocyte chemoattractant protein; MIP ⫽ macrophage inflammatory protein; VEGF ⫽ vascular endothelial growth factor.

Supplemental data at www.neurology.org

Amyotrophic lateral sclerosis (ALS) is a complex, progressive neurodegenerative disease that is difficult to diagnose early in its course because initial symptoms and signs often are similar to those of more common conditions, and there is no specific diagnostic test for ALS. The pathogenesis of ALS is largely unknown; thus identification of biomarkers associated with ALS could eventually assist early diagnosis and aid understanding of the disease by providing insights into its pathogenesis.1 As defined by the NIH Biomarkers Definitions Working Group, a biomarker is “a characteristic that is objectively measured and evaluated as an indicator of normal biologic processes, pathogenic processes or pharmacologic responses to a therapeutic

Editorial, page 11 e-Pub ahead of print on November 5, 2008, on www.neurology.org. From the Departments of Neurosurgery (R.M.M., W.T.R., J.R.C.), Pharmacology (W.M.F.), and Neurology (H.E.S., Z.S.), George M. Leader Family Laboratory, Pennsylvania State University College of Medicine/Milton S. Hershey Medical Center, Hershey; and Department of Nutrition (J.L.B.), Pennsylvania State University, College Park. Supported by funds from The Judith and Jean Pape Adams Charitable Foundation, The Paul and Harriett Campbell Fund for ALS Research, The Zimmerman Family Love Fund, and the ALS Association Greater Philadelphia Chapter. Disclosure: The authors report no disclosures. 14

Copyright © 2009 by AAN Enterprises, Inc.

Table 1

Comparison of CSF samples from patients with amyotrophic lateral sclerosis (ALS) and neurologic disease controls

Disease status

ALS

Neurologic disease controls

No.

41

33

Clinically definite

4

Clinically probable

15

Clinically probable, laboratory supported

12

Clinically possible

10

Male:female

27:14

11:22

Age (y), mean (SEM)

58.8 (⫾1.8)

43.9 (⫾2.3)

H63D carriers

14

7

5

5

C282Y carriers Limb:bulbar onset

32:9

Time from onset (mo), mean (SEM)

16.6 (⫾2.4)

ALSFRS-R, mean (SEM)

39.5 (⫾1.0)

ALSFRS-R ⫽ ALS Functional Rating Scale-revised.

intervention.”1 Biomarkers may also be used as indicators of disease progression and as measures of treatment effects. Finally, a comprehensive panel of biomarkers may help guide stratification of patients for different treatments based on etiopathogenesis. A number of studies have been undertaken to identify biomarkers associated with ALS.2-8 While many of these studies have provided clues about pathogenetic mechanisms involved in the disease, most have examined only a small number of proteins. Several studies have examined proteomic profiles of patients with ALS compared to various control groups.8-10 These proteomic studies have provided valuable examples of proteins that can distinguish patients with ALS from control groups, but most proteomic techniques are better suited for abundant proteins. We provide in this study an analysis of a panel of analytes that are associated with inflammation and trophic support that may more accurately reflect early stages of disease and cell response. Our first hypothesis was that a panel of biomarkers could be identified in the CSF that will support the clinical diagnosis. Extensive evidence has suggested ALS pathogenesis involves excessive neuroinflammation,11 aberrant growth factor regulation,12 and iron dyshomeostasis,13 among other factors. Despite many attempts to identify causes of sporadic ALS, no genetic polymorphisms have been identified to account for a large number of cases.14-16 The H63D polymor-

phism in the hemochromatosis gene (HFE) has been examined in multiple published studies,17,18 with an overall OR for patients with ALS possessing at least one H63D allele of 1.26 (95% CI 1.09–1.46) making this genetic variant the most frequently associated with ALS. HFE is involved in mediating iron homeostasis, inflammatory responses, and innate immunity.19 Therefore, we also tested the hypothesis that HFE gene variants will be associated with altered profiles in the panel of CSF biomarkers. METHODS Patients and samples. We obtained blood samples by venipuncture and CSF samples by lumbar puncture at the time of evaluation from patients who were undergoing CSF examination as part of their diagnostic evaluation in the outpatient Neurology clinic. Patient demographics are described in table 1. These patients were grouped into those with ALS (clinically definite, probable, probable laboratory-supported, or possible ALS),20 and those who presented with neurologic symptoms but ultimately were found not to have ALS (neurologic disease controls). Demographic and selected medical data were obtained from the patients’ medical records. The ALS Functional Rating Scale Score-Revised (ALSFRS-R)21 was completed for each patient with ALS at an outpatient visit within 2 months of the lumbar puncture. All patients provided informed consent. This study was approved by the Institutional Review Board of the Penn State Milton S. Hershey Medical Center and Penn State College of Medicine. CSF samples were obtained between 8 AM and 12 PM, to limit changes related to a circadian rhythm, from a mostly Caucasian population. Samples were frozen immediately after collection and were later thawed on ice and centrifuged to remove any particulate matter. Protease inhibitor cocktail (Sigma-Aldrich; St. Louis, MO) was then added 1:100, and samples were refrozen at – 80°C in 200 ␮L aliquots.

HFE genotyping. DNA was purified from white blood cells using the QIAamp DNA Mini kit (Qiagen; Valencia, CA). All patients were genotyped for the H63D and C282Y HFE polymorphisms by restriction fragment length analysis as previously reported.17 Multiplex cytokine bead assay. We performed multiplex analysis on undiluted CSF supernatants using the Bio-Plex Human 27-plex panel of cytokines and growth factors (Bio-Rad; Hercules, CA). The proteins in this panel as well as additional analytes are listed in table 2. Briefly, 1% bovine serum albumin (BSA) (Sigma-Aldrich; St. Louis, MO) was added to 200 ␮L of each CSF sample and standards were reconstituted in PBS with 1% BSA. Fifty ␮L of each sample or standard was added in duplicate to a 96-well filter plate and mixed with 50 ␮L of antibody-conjugated beads for 1 hour at room temperature. After 1 hour, wells were washed and 25 ␮L of detection antibody was added to each well. After a 30-minute incubation, wells were washed and 50 ␮L of streptavidin-PE was added to each well and incubated for 10 minutes. A final wash cycle was then completed and 125 ␮L of assay buffer was added to each well. The plate was then analyzed using a Bio-Plex 200 workstation (Bio-Rad). Analyte concentration was calculated based on the respective standard curve for each cytokine. Immunoassays. CSF levels of ␤2-microglobulin (US Biologic; Swampscott, MA) and transferrin (Bethyl Laboratories; MontNeurology 72

January 6, 2009

15

Table 2

All markers screened in our panel of potential biomarkers

␤-2 microglobulin

IL-1ra

IL-9

IL-17

TNF-␣

Eotaxin

IL-2

IL-8

IFN-␥ induced protein-10

Fibroblast growth factor basic

Granulocyte colony stimulating factor

IL-4

IL-10

Monocyte chemoattractant protein-1

PDGF bb

Granulocyte-monocyte colony stimulating factor

IL-5

IL-12 (p70)

Macrophage inflammatory protein-1␣

VEGF

IFN-␥

IL-6

IL-13

Macrophage inflammatory protein-1␤

Total iron

IL-1␤

IL-7

IL-15

RANTES

Transferrin

IFN ⫽ interferon; IL ⫽ interleukin; TNF ⫽ tumor necrosis factor; PDGF ⫽ platelet-derived growth factor; VEGF ⫽ vascular endothelial growth factor.

gomery, TX) were assayed by ELISA according to the manufacturers’ protocols.

Atomic absorption spectroscopy. The amount of iron in the CSF was determined by digesting the CSF in ultrapure Nitric Acid (JT Baker, 9598-00; Phillipsburg, NJ), 1:4 v/v, and samples were heated to 60°C for 24 hours. The digested samples were diluted 1:100 in ddH2O, and then analyzed on a Perkin Elmer Atomic Absorption Spectrometer 600 series (Waltham, MA). Statistical analysis. Multifactorial analysis of analyte expression was performed using GeneSpring GX version 7.3.1 (Agilent Technologies; Santa Clara, CA). Normal distribution of analyte expression was assessed with the Kolmogorov-Smirnov test using SigmaStat 2.03 (SPSS, Inc.; Chicago, IL). Biomarkers were compared between groups via t test or Mann–Whitney U test, as appropriate, and differences were considered significant if p ⬍ 0.05. Correlations between markers and ALSFRS-R, duration of symptoms, and age were assessed by the Spearman or Pearson correlation coefficient, as appropriate, with p ⬍ 0.05 considered significant. Classification statistics were generated using a support vector machine algorithm with radial basis and polynomial dot product kernel functions and a diagonal scaling factor ranging from zero to five. Classification of each sample by disease status was determined by crossvalidation in a leave one out strategy in which each sample was sequentially blinded. Each sample is individually removed from the sample set and the algorithm seeks to classify the sample compared to the others.

CSF was obtained from 39 patients with sporadic ALS and two patients with familial ALS for a total of 41 patients with ALS (9 with bulbar onset, 32 with limb onset). CSF was also obtained from 33 neurologic disease controls. The diagnoses for these neurologic disease control patients are listed in table e-1 on the Neurology® Web site at www.neurology.org. The characteristics of the two groups are given in table 1. All biomarkers on the panel were detectable in the CSF of the majority of the samples, with the exception of IL1␤, which was not detected in any sample. Expression levels of analytes that increased or decreased with increasing age of subjects were age-adjusted by linear regression (table e-2). The expression of two biomarkers differed by sex (table e-2). Between patients with ALS and neurologic controls, the expression of 11 biomarkers was signifi-

RESULTS

16

Neurology 72

January 6, 2009

cantly higher in the CSF of patients with ALS, while the expression of two biomarkers was significantly higher in controls, as shown in table 3. A support vector machines algorithm was used to classify each sample as ALS or control in a leave one out crossvalidation strategy with an accuracy of 86.5% using all assayed markers. The best accuracy was obtained using only the markers with the five most significant p values (IL-10, IL-6, GM-CSF, IL-2, and IL-15) with a first order polynomial dot product kernel function and a diagonal scaling factor of one. Limit-

Table 3

Marker

Biomarkers significantly different between patients with amyotrophic lateral sclerosis (ALS) and neurologic disease controls by t test or Mann-Whitney U test, as appropriate p Value

Fold difference

ALS >neurologic disease control IL-6

0.000001

1.25

GM-CSF

0.000021

1.4

IL-2

0.000428

1.19

IL-15

0.001511

1.29

IL-17

0.002101

1.3

MIP-1b

0.002165

1.17

FGF basic

0.005317

1.67

G-CSF

0.007361

1.51

VEGF

0.00742

1.3

MIP-1a

0.042665

1.08

MCP-1

0.047217

1.25

Neurologic disease control >ALS IL-10

⬍0.000001

1.66

IFN-␥

0.032836

1.26

IL ⫽ interleukin; GM-CSF ⫽ granulocyte-monocyte colony stimulating factor; MIP ⫽ macrophage inflammatory protein; FGF ⫽ fibroblast growth factor; G-CSF ⫽ granulocyte colony stimulating factor; VEGF ⫽ vascular endothelial growth factor; MCP ⫽ monocyte chemoattractant protein; IFN ⫽ interferon.

Table 4

Biomarkers were stratified by HFE genotype at the 63rd amino acid position and the 282nd amino acid position

Marker

p

Fold difference

Genotype at 63rd amino acid H63D >Wt B2M

0.00202

1.16

IL-8

0.07

1.09

Genotype at 282nd amino acid C282Y >Wt PDGF bb

0.00851

1.59

IL-12

0.0256

1.3

IL-7

0.0471

1.15

IL ⫽ interleukin; PDGF ⫽ platelet-derived growth factor.

ing the analysis to the five most significant biomarkers enabled us to distinguish patients with ALS from controls with 89.2% accuracy, 87.5% sensitivity, and 91.2% specificity. No markers differed significantly between patients with ALS with limb onset vs bulbar onset or significantly correlated with duration of symptoms. The expression of IL-8, however, was higher in those patients with lower ALSFRS-R scores, an indicator of disease progression (table e-3). Fourteen patients with ALS carried an H63D HFE variant (3 homozygotes, 11 heterozygotes), and 7 control patients (1 homozygote, 6 heterozygotes) carried an H63D HFE variant. Both the ALS patient group and the neurologic disease control patient group had five subjects carrying C282Y HFE variants (one control homozygote, all others heterozygous). Heterozygotes and homozygotes were grouped together because of the relatively small number of homozygotes. Additionally, the two disease groups were considered together to determine the association between biomarker expression and HFE genotypes. Biomarkers differing by HFE genotype are given in table 4. There were no significant differences of iron concentration in the CSF for any of the comparison groups (data not shown). The results of this study support our hypotheses that the profile of inflammatory and antiinflammatory cytokines, growth factors, and analytes reflective of iron homeostasis differs between patients with ALS and a group of neurologic disease control patients. It has been proposed that ALS results from triggering events causing a cascade leading toward selective motor neuron death in genetically susceptible individuals.22 This study takes a novel approach toward the development of a panel of CSF biomarkers at one point during the ALS disease process. Our

DISCUSSION

approach does not clarify whether inflammatory processes precede disease onset or result from it, but it does reveal inflammatory activity early in the disease process. No markers differed between patients with ALS with limb vs bulbar onset suggesting similar pathologic processes irrespective of the site of disease onset. Each of the five most significantly different cytokines between patients with ALS and neurologic disease controls can be linked to disease pathogenesis. One marker increased in the neurologic disease control group compared to patients with ALS was IL-10, which is an anti-inflammatory cytokine known to inhibit microglial activation.23 IL-6 is considered to be an inflammatory cytokine, but is also known to have anti-inflammatory and neurotrophic properties.24 GM-CSF is regarded as a proliferator and differentiator of neutrophilic, eosinophilic, and monocytic cellular lineages.25,26 IL-2 is produced mainly in T lymphocytes and acts to stimulate growth and cytotoxicity of activated T lymphocytes.27 IL-15 is a T lymphocyte chemoattractant also shown to activate microglia28 and upregulate the production of other chemoattractants including IL-8 and MCP-1.29 Indeed, expression of MCP-1 as well as MIP-1␣ and MIP-1␤ were all significantly increased in patients with ALS compared to controls. This study is consistent with theories that suggest ALS pathogenesis involves inflammatory activation.30 The biomarker panel also is consistent with the overall concept that microglia recruitment and activation are key components of ALS pathogenesis.5,31-33 Activated microglia are a source of the leukocyte chemoattractant IL-834 and this was the only protein whose expression was related to ALSFRS-R. This relationship showed higher levels of IL-8 in the CSF of those patients with lower ALSFRS-R scores, consistent with evidence suggesting that T lymphocytes accumulate in regions of motor neuron loss.32 Accumulation of T lymphocytes can in turn lead to further recruitment and activation of microglia, and cytotoxic mediators produced by these cells may be detrimental to motor neurons. Several studies have reported an increased risk of ALS in carriers of the H63D HFE polymorphism.17,18 The C282Y variant of the HFE gene has not been reported to increase risk of ALS although this rarer allelic variant may simply be underrepresented in the studies to date.18 Both of these common HFE gene variants increase cellular iron accumulation,35,36 but the phenotype of cells carrying the allelic variants is different.36 In vivo studies in humans and animals reveal that HFE variants are associated with loss of iron homeostasis, exacerbated inflammatory responses, and alterations in innate immunity,19 all of which may be considered part of the pathogenic Neurology 72

January 6, 2009

17

process in ALS. The increase in ␤2M in the CSF associated with the H63D HFE allele may reflect increased turnover of the HFE-␤2M complex or may be a marker of more general membrane protein turnover, particularly from immune cells.37 A study in a population of hemochromatosis patients showed that patients carrying the H63D HFE allele had higher plasma levels of the chemokine MCP-1 than patients homozygous for the C282Y variant, or wildtype controls.38 Consistent with previous studies,7 MCP-1 was elevated in patients with ALS compared to controls in our biomarker panel. MCP-1 expression, however, did not differ by HFE genotype. Only one of the markers, IL-8, trended toward an increase in those individuals carrying the H63D allele. In the current study, the expression of several markers was higher in subjects carrying a C282Y HFE allele (table 4), but an association of this allele with ALS or other neurodegenerative disease has not been established. Future studies incorporating larger numbers of subjects with HFE variants as well as subjects homozygous for the H63D and C282Y alleles will be necessary to further define the biomarker profiles associated with these variants. The biomarker panel distinguished ALS cases from neurologic disease controls, consistent with previous proteomic studies.3,8 Our data expand the previous studies and show promise that a biomarker panel could be developed for aiding in the diagnosis of ALS. Future validation studies should incorporate samples from multiple clinics and from patients with syndromes that mimic ALS. To establish a predictive value for this biomarker panel, serial analysis of individual patients may provide a better assessment of biomarkers reflecting disease progression.

6.

7.

8.

9.

10.

11. 12. 13.

14.

15.

16.

17. ACKNOWLEDGMENT The authors thank all the patients who participated in this study. The authors thank Scot Kimball, PhD, and Lydia Kutzler for their technical expertise and Dave Mauger, PhD, for statistical assistance.

18.

Received January 7, 2008. Accepted in final form May 21, 2008. 19. REFERENCES 1 Biomarkers and surrogate endpoints: preferred definitions and conceptual framework. Clin Pharmacol Ther 2001; 69:89–95. 2. Henkel JS, Engelhardt JI, Siklos L, et al. Presence of dendritic cells, MCP-1, and activated microglia/macrophages in amyotrophic lateral sclerosis spinal cord tissue. Ann Neurol 2004;55:221–235. 3. Ranganathan S, Williams E, Ganchev P, et al. Proteomic profiling of cerebrospinal fluid identifies biomarkers for amyotrophic lateral sclerosis. J Neurochem 2005;95:1461–1471. 4. Cronin S, Greenway MJ, Ennis S, et al. Elevated serum angiogenin levels in ALS. Neurology 2006;67:1833–1836. 5. Tanaka M, Kikuchi H, Ishizu T, et al. Intrathecal upregulation of granulocyte colony stimulating factor and its neuro18

Neurology 72

January 6, 2009

20.

21.

22.

protective actions on motor neurons in amyotrophic lateral sclerosis. J Neuropathol Exp Neurol 2006;65:816–825. Mitsumoto H, Ulug AM, Pullman SL, et al. Quantitative objective markers for upper and lower motor neuron dysfunction in ALS. Neurology 2007;68:1402–1410. Nagata T, Nagano I, Shiote M, et al. Elevation of MCP-1 and MCP-1/VEGF ratio in cerebrospinal fluid of ALS patients. Neurol Res 2007;29:772–776. Ranganathan S, Nicholl GC, Henry S, et al. Comparative proteomic profiling of cerebrospinal fluid between living and post mortem ALS and control subjects. Amyotroph Lateral Scler 2007;8:1–7. Pasinetti GM, Ungar LH, Lange DJ, et al. Identification of potential CSF biomarkers in ALS. Neurology 2006;66: 1218–1222. Ramstrom M, Ivonin I, Johansson A, et al. Cerebrospinal fluid protein patterns in neurodegenerative disease revealed by liquid chromatography–Fourier transform ion cyclotron resonance mass spectrometry. Proteomics 2004;4: 4010–4018. McGeer PL, McGeer EG. Inflammatory processes in amyotrophic lateral sclerosis. Muscle Nerve 2002;26:459–470. Ekestern E. Neurotrophic factors and amyotrophic lateral sclerosis. Neurodegen Dis 2004;1:88–100. Kasarskis EJ, Tandon L, Lovell MA, Ehmann WD. Aluminum, calcium, and iron in the spinal cord of patients with sporadic amyotrophic lateral sclerosis using laser microprobe mass spectroscopy: a preliminary study. J Neurol Sci 1995; 130:203–208. Schymick JC, Talbot K, Traynor BJ. Genetics of sporadic amyotrophic lateral sclerosis. Hum Mol Genet 2007;16: R233–242. Schymick JC, Scholz SW, Fung HC, et al. Genome-wide genotyping in amyotrophic lateral sclerosis and neurologically normal controls: first stage analysis and public release of data. Lancet Neurol 2007;6:322–328. Cronin S, Berger S, Ding J, et al. A genome-wide association study of sporadic ALS in a homogenous Irish population. Hum Mol Genet 2007;17:768–774. Wang XS, Lee S, Simmons Z, et al. Increased incidence of the Hfe mutation in amyotrophic lateral sclerosis and related cellular consequences. J Neurol Sci 2004;227:27–33. Sutedja NA, Sinke RJ, Van Vught PW, et al. The association between H63D mutations in HFE and amyotrophic lateral sclerosis in a Dutch population. Arch Neurol 2007; 64:63–67. Roy CN, Custodio AO, de Graaf J, et al. An Hfedependent pathway mediates hyposideremia in response to lipopolysaccharide-induced inflammation in mice. Nat Genet 2004;36:481–485. Brooks BR MR, Swash M, Munsat TL, for the World Federation of Neurology Research Group on Motor Neuron Diseases. El Escorial revisited: revised criteria for the diagnosis of amyotrophic lateral sclerosis. Amyotroph Lateral Scler Other Motor Neuron Disord 2000;1:293–299. Cedarbaum JM, Stambler N, Malta E, et al. The ALSFRS-R: a revised ALS functional rating scale that incorporates assessments of respiratory function. BDNF ALS Study Group (Phase III). J Neurol Sci 1999;169:13–21. Majoor-Krakauer D, Willems PJ, Hofman A. Genetic epidemiology of amyotrophic lateral sclerosis. Clin Genet 2003;63:83–101.

23.

Lee YB, Nagai A, Kim SU. Cytokines, chemokines, and cytokine receptors in human microglia. J Neurosci Res 2002;69:94–103. 24. Sekizawa T, Openshaw H, Ohbo K, Sugamura K, Itoyama Y, Niland JC. Cerebrospinal fluid interleukin 6 in amyotrophic lateral sclerosis: immunological parameter and comparison with inflammatory and non-inflammatory central nervous system diseases. J Neurol Sci 1998;154:194–199. 25. Lee SC, Liu W, Brosnan CF, Dickson DW. GM-CSF promotes proliferation of human fetal and adult microglia in primary cultures. Glia 1994;12:309–318. 26. Franzen R, Bouhy D, Schoenen J. Nervous system injury: focus on the inflammatory cytokine ‘granulocyte-macrophage colony stimulating factor.’ Neurosci Lett 2004;361:76–78. 27. Grande C, Firvida JL, Navas V, Casal J. Interleukin-2 for the treatment of solid tumors other than melanoma and renal cell carcinoma. Anticancer Drugs 2006;17:1–12. 28. Huang Z, Ha GK, Petitto JM. IL-15 and IL-15R alpha gene deletion: effects on T lymphocyte trafficking and the microglial and neuronal responses to facial nerve axotomy. Neurosci Lett 2007;417:160–164. 29. Badolato R, Ponzi AN, Millesimo M, Notarangelo LD, Musso T. Interleukin-15 (IL-15) induces IL-8 and monocyte chemotactic protein 1 production in human monocytes. Blood 1997;90:2804–2809. 30. Boillee S, Yamanaka K, Lobsiger CS, et al. Onset and progression in inherited ALS determined by motor neurons and microglia. Science 2006;312:1389–1392. 31. Graves MC, Fiala M, Dinglasan LA, et al. Inflammation in amyotrophic lateral sclerosis spinal cord and brain is medi-

32.

33.

34.

35.

36.

37.

38.

ated by activated macrophages, mast cells and T cells. Amyotroph Lateral Scler Other Motor Neuron Disord. 2004;5:213–219. Engelhardt JI, Tajti J, Appel SH. Lymphocytic infiltrates in the spinal cord in amyotrophic lateral sclerosis. Arch Neurol 1993;50:30–36. Kawamata T, Akiyama H, Yamada T, McGeer PL. Immunologic reactions in amyotrophic lateral sclerosis brain and spinal cord tissue. Am J Pathol 1992;140:691–707. Ehrlich LC, Hu S, Sheng WS, et al. Cytokine regulation of human microglial cell IL-8 production. J Immunol 1998; 160:1944–1948. Feder JN, Penny DM, Irrinki A, et al. The hemochromatosis gene product complexes with the transferrin receptor and lowers its affinity for ligand binding. Proc Natl Acad Sci USA 1998;95:1472–1477. Lee SY, Patton SM, Henderson RJ, Connor JR. Consequences of expressing mutants of the hemochromatosis gene (HFE) into a human neuronal cell line lacking endogenous HFE. Faseb J 2007;21:564–576. Nielsen OH, Vainer B, Madsen SM, Seidelin JB, Heegaard NH. Established and emerging biological activity markers of inflammatory bowel disease. Am J Gastroenterol 2000;95:359–367. Lawless MW, White M, Mankan AK, O’Dwyer MJ, Norris S. Elevated MCP-1 serum levels are associated with the H63D mutation and not the C282Y mutation in hereditary hemochromatosis. Tissue Antigens 2007; 70:294–300.

Learn. Earn. Network. 2009 AAN Annual Meeting: An Excellent Value • Learn about the latest scientific advances in neurology • Earn valuable CME credit and fulfill Maintenance of Certification requirements • Network with your peers at exciting social events all week long • Enjoy the convenience and value of all this and more—in just one meeting Early registration and hotel deadline is March 20, 2009. Register today at www.am.com/AM2009.

Neurology 72

January 6, 2009

19

A novel Refsum-like disorder that maps to chromosome 20

T. Fiskerstrand, MD, PhD P. Knappskog, PhD J. Majewski, PhD R.J. Wanders, PhD H. Boman, MD, PhD L.A. Bindoff, MD, PhD

Address correspondence and reprint requests to Professor Laurence Bindoff, Department of Neurology, Haukeland University Hospital, N-5021 Bergen, Norway [email protected]

ABSTRACT

Objective: Clinical and genetic characterization of a neurologic disorder resembling Refsum disease in a Norwegian consanguineous family.

Methods: The affected individuals comprise a brother and sister and their third cousin. The family comes from a small island community and genealogic studies showed that both sets of parents are descendants of a man born in 1585. Based on the hypothesis that this is an autosomal recessive disease and that the patients were homozygous for the same mutation (identical by descent), we used homozygosity mapping to define the genetic locus of this disorder.

Results: This slowly progressive disorder starts in childhood with signs of peripheral neuropathy (pes cavus, tendoachilles contracture). Hearing loss and cataract become evident in the third decade. Subsequently, patients develop a disorder of gait due to the combination of ataxia and spasticity, and a pigment retinopathy. While the clinical picture is reminiscent of Refsum disease, affected individuals have normal phytanic and pristanic acid levels in plasma, as well as normal enzymatic activity for ␣-oxidation. We mapped the disease to a 15.96 Mb region on chromosome 20 (20p11.21-q12), containing approximately 200 genes (maximum lod score ⫽ 6.3). Sequencing of 23 candidate genes failed to demonstrate detrimental sequence variants.

Conclusions: Our findings show that the clinical syndromes that include Refsum disease are more heterogeneous than previously recognized. We have chosen to report the clinical features and mapping of this novel disorder in the hope that this will permit identification of other families and thus proper genetic characterization. Neurology® 2009;72:20–27 GLOSSARY HMSN ⫽ hereditary motor and sensory neuropathy; IBD ⫽ identical by descent; NARP ⫽ neuropathy, ataxia, and retinitis pigmentosa; SCA7 ⫽ spinocerebellar ataxia type 7.

The hereditary neuropathies constitute a heterogeneous group of diseases with around 30 loci and 14 genes identified.1,2 Classification of these disorders still employs a combination of clinical, neurophysiologic, and genetic parameters.3 Clinically, these disorders may be divided into pure and complex forms, differentiated by the presence of additional symptoms such as deafness, ocular disease (e.g., retinitis pigmentosa, cataract), cranial nerve, and CNS involvement.1 Complex forms are often recessively inherited and account for less than 10% of inherited neuropathies in the European population.4 Refsum disease (HMSN type 4, heredopathia atactica polyneuritiformis)5 comprises the combination of pigmentary retinal degeneration, chronic neuropathy, and ataxia. Deafness, cataract, miosis, anosmia, cardiac, and skin involvement are also commonly present. Refsum disease is heterogeneous, although all of the different types so far described share a common pathogenesis, being caused by defects in peroxisomal function. The disorder is autosomal Editorial, page 13 e-Pub ahead of print on November 12, 2008, at www.neurology.org. From the Center for Medical Genetics and Molecular Medicine (T.F., P.K., H.B.) and Department of Neurology (L.A.B.), Haukeland University Hospital, Bergen; Department of Clinical Medicine (P.K., H.B., L.A.B.), University of Bergen, Norway; Department of Human Genetics (J.M.), McGill University and Genome Que´bec Innovation Centre (J.M.), Montreal, Que´bec, Canada; and Department of Pediatrics and Clinical Chemistry, Laboratory of Genetic Metabolic Diseases (R.J.W.), Academic Medical Center, University of Amsterdam, The Netherlands. Supported by Helse Vest (Western Norway Regional Health Authority) (911308 to P.K., T.F., H.B.). Disclosure: The authors report no disclosures. 20

Copyright © 2009 by AAN Enterprises, Inc.

recessively inherited and the adult type is caused by mutations in the PAHX gene encoding the enzyme phytanoyl-CoA hydroxylase6 or the PEX7 gene7 encoding the receptor for the type 2 peroxisomal targeting signal (PTS2). We have investigated a Norwegian family comprising a pair of siblings and their third cousin who had features highly suggestive of Refsum disease, without disturbance of ␣-oxidation. The clinical classification of this disease has been difficult, but the possibility of genetic characterization emerged as we discovered that all four parents of the affected are related. Using homozygosity mapping,8 we identified a candidate region for this disease locus on chromosome 20. METHODS Subjects. The affected individuals comprise two siblings (V-1, V-2) and their third cousin (V-4) (figure). Both sets of healthy parents, a healthy brother of V-1 and V-2 (V-3), and three healthy sisters of V-4 (V-5, V-6, V-7) agreed to participate in this study. Informed consent was obtained according to the Declaration of Helsinki. The healthy individuals were not subject to clinical investigation, but the affected individuals have all been thoroughly investigated to exclude conditions that can cause the observed clinical features (table 1).

Genealogic studies and evaluation of family for homozygosity mapping. Genealogic studies used printed local histories covering the island community from which the family originated, together with data from some of the nearby counties, church records, and national censuses. We also used data from a private genealogic study with ⬎18,000 names available on the Internet. The finding that all four parents of the affected are descendants of a man born ca 1585 (and his wife) strengthened our hypothesis that the affected are homozygous for a rare mutation. The nearest common ancestral couple for the parents of V-1 and V-2, where one of the common ancestors is also related to the affected third cousin (V-4), was found six to seven generations back. According to Genin et al.,9 V-1 (or V-2) should be homozygous by chance for segments with a size of about 12.5 centiMorgan (cM) (identical by descent [IBD]). Similarly, V-4 was expected to be homozygous by chance (IBD) for segments with a size of approximately 11 cM. We decided, therefore, to perform homozygosity mapping by microsatellite markers.

Genotyping. Genomic DNA was isolated from whole blood by using an automated DNA extraction system GenoM48 (QIAGEN, Hilden, Germany). A genome-wide scan was performed using a set of 400 microsatellite markers with an average spacing of 10 cM (PRISM Linkage Mapping Set MD, Version 2; Applied Biosystems [ABI], Foster City, CA). PCR and pipetting were performed using the ABI Catalyst 800 Turbo Lab station and PCR products analyzed using an ABI 3100 Genetic Analyzer with the Genescan Analysis software (Applied Biosystems). High-density mapping was performed with microsatellite markers identified in the National Center for Biotechnology information database.10 Linkage analysis. The program Pedcheck11 was used to check for Mendelian errors in the genotype data. Inconsistent genotypes were replaced by an unknown status. All data format con-

versions were carried out using the program Mega2.12 We used a recessive inheritance model with full penetrance and no phenocopies, and a population disease allele frequency of 0.001. Marker allele frequencies were estimated using the four parents of the affected individuals. For the initial genome scan, exact single-point and multipoint parametric linkage analyses were performed using Allegro version 1.113 on a truncated pedigree (figure, numbered individuals). This was necessitated by time and memory constraints of the analyses. For the fine-mapping analyses on chromosome 20, the program Simwalk214,15 was used to process the pedigree including inbreeding loops (figure, individuals shown in gray) necessary to demonstrate common ancestry of the affected individuals.

DNA sequencing and mutation detection. For all genes investigated, we sequenced one of the affected and one of his or her parents. PCR primers for amplification of exons and flanking intron sequences (of candidate genes) were designed using the Oligo 6.3 program (National Bioscience, Plymouth). Sequence information is available on request. PCR amplification was performed using standard procedures and AmpliTaq Gold DNA polymerase (ABI). PCR products were treated with SAP/exonuclease I (Amersham Bioscience, Uppsala, Sweden) and sequenced (Prism BigDye terminator, v 1.1; ABI) on the 3100- or the 3730 Genetic Analyser (ABI). Data analysis was assisted by use of the programs Seqscape and Lalign. RESULTS Clinical features and investigations. The initial clinical diagnosis considered in individuals V-1 and V-2 was Refsum disease; however, phytanic and very-long-chain fatty acids were normal in all of the affected individuals. ␣-Oxidation was also investigated in cultured fibroblasts (V-2) with normal findings. The latter excludes a defect in the ␣-oxidation system as observed in fibroblasts from patients with Refsum disease, due to mutations in the gene coding for phytanoyl-CoA hydroxylases.16 Before proceeding to homozygosity mapping, other metabolic disorders, including some mitochondrial diseases, were investigated (table 2). Muscle histology and histochemistry was performed in two individuals (V-1, V-2) and showed no evidence of a mitochondrial or other metabolic disorder, although neurogenic changes (due to the neuropathy) were evident. The combination of retinitis pigmentosa and ataxia led us to check for spinocerebellar ataxia type 7 (SCA7) and sequence mitochondrial DNA for the mutations that cause neuropathy, ataxia, and retinitis pigmentosa (NARP) (table 2). Clinical findings in the affected are summarized in table 1, and laboratory findings in table 2.

Patient 1 (V-1). This woman, now 59 years old, was

healthy at birth, but walked late and underwent tendoachilles release at the age of 12 years. Hearing and visual problems started in her early 20s, and sensorineural hearing loss was confirmed at age 29 years. Bilateral subcapsular cataracts were removed at the age of 29 and 33 years, and she has undergone repeated operations to remove residual cataract since. Neurology 72

January 6, 2009

21

Figure

Pedigree and haplotypes

Pedigree: The four parents (IV-1–IV-4) of the affected are individually interrelated in several ways, but not all of the inbreeding loops are shown here. In the first linkage analysis (Allegro v.1.1), a truncated version of the pedigree was used (included individuals are numbered). Truncation was necessary due to computational restraints. After finemapping, we performed a new linkage analysis with Simwalk2, and included consanguinity loops for all four parents (IV-1–IV-4), back eight to nine generations to the closest common ancestral couple. The maximum lod score for the region on chromosome 20 was 6.3. Haplotypes: Microsatellite markers in the 20p11.21-q12-region are given in the left columns in consecutive order (telomeric p-arm on top). Various alleles are given as the amplified fragment sizes. Parental haplotypes have been given different colors, with the suspected ancestral haplotype in red. The locus is limited by ancestral recombinations in individual IV-1, between the markers D20S477 and D20S184 on the p-arm, and between D20S607 and D20S107 on the q-arm (dashed lines). For marker D20S478, we find the allele 264 in the ancestral haplotype in individual IV-1, as well as in V-1 and V-2, who both inherited this. All other individuals who are heterozygous or homozygous for the ancestral haplotype have the allele 268. This marker is a tetrarepeat, and this finding may be explained by a mutation, reducing the original 268-allele in an ancestor of IV-1 by four bases.

22

Neurology 72

January 6, 2009

Table 1

Comparison of clinical features Patient Patient Patient V-1 V-2 V-4 ⫹

⫹

⫹

Sensory and motor neuropathy ⫹

⫹

⫹

Sensorineural hearing loss

⫹

⫹

⫹

Ataxia

⫹

⫹⫹

⫹(⫹)

Hyperreflexia

⫺

⫹

⫺

Extensor plantar response

⫺

⫹

⫹

Tapetoretinal disease

⫹

⫹

Optic atrophy

⫹

⫺

⫺

Tremor (intention)

⫺

⫹

⫹

Cerebellar dysarthria

(⫹)

⫹

⫺

Anosmia

⫺

NT

NT

Skin involvement

⫺

⫺

⫺

Early cataract

(⫹)

NT ⫽ not tested.

Electroretinography performed at age 38 years showed signs of tapetoretinal disease and repeat examination at age 52 showed that the rod response was extinguished bilaterally, while the cone response was low to low normal. Ophthalmoscopy showed optic atrophy. Pes cavus and signs of a peripheral neuropathy (sensory loss and absent ankle reflexes) were detected at age 38, when she was investigated for back pain. Subsequent neurophysiologic studies showed a demyelinating sensory, motor peripheral neuropathy:median motor conduction velocity 24 m/s (amplitude 4.9 mv), sensory conduction 30 m/s; peroneus (motor) 20 m/s (amplitude 1.25 mV). The diagnosis of Refsum disease was considered, but plasma phytanic acid levels were normal. She has developed a slowly progressive gait disturbance with signs of increasing peripheral sensory loss (both spinothalamic and vibration sense), but no clear signs of cerebellar or pyramidal tract disease. She now uses an electric wheelchair for longer distances. MRI scan of the brain was normal. Muscle biopsy showed evidence of muscle fiber atrophy, with both widespread and small group atrophy, mostly affecting type 2 fibers. There was no evidence of mitochondrial disease. Biochemical studies including phytanic and pristanic acid measurements were normal (table 2). Patient 2 (V-2). Patient 2 is the 53-year-old brother

of Patient 1. Pes cavus was noted in childhood. He was first referred to a neurologist because of unsteady gait at age 37 years. He felt that his legs had always been stiff and thought that his unsteadiness was worse in the dark. In addition, he had tremor in both hands that came with use and disappeared with rest. Reduced hearing became apparent in his 30s and retinitis pigmentosa was found around the same time as

he was referred for neurologic evaluation. Examination confirmed pes cavus, sensorineural deafness, and retinal pigmentation. His gait was ataxic. Reflexes were difficult to elicit apart from those at the knee, and sensory testing showed a glove and stocking loss, predominantly to spinothalamic modalities. Refsum disease was considered, but phytanic acid level was found to be normal. Examination 15 years later (age 52) showed pupillary abnormalities after cataract surgery, normal eye movements, and pigmentary changes in both retinas. Jaw jerk was normal. There was distal amyotrophy in the legs, spasticity, and weakness, particularly of hip and knee flexion. Patellar reflexes were symmetrically increased; ankle reflexes were diminished with positive Babinski bilaterally. He had bilateral terminal intention tremor, heel-shin ataxia, and a gait showing signs of both spasticity and ataxia. Sensory testing showed a stocking loss to spinothalamic modalities, loss of vibration sense, but normal proprioception. Nerve conduction velocities were severely reduced; motor responses ulnar/median 28 –34 m/sec (amplitudes 6 mV/2.5 mV); posterior tibial/peroneal 22–33 m/s (amplitudes 400/25 ␮V). EMG showed chronic neurogenic changes in all muscles sampled, particularly in the hand muscles. No sensory responses were obtained from median or sural nerves. EEG was normal, as were ECG and cardiac ultrasound examination. Cerebral CT and MRI (the latter was performed when he was 47 years old) were normal. Star shaped subcapsular cataracts were found in both eyes, along with pigmentary changes in the midperipheral field. He underwent cataract surgery at the ages of 49 and 50. In 2005, we also performed analysis of oxidation of C26:0, pristanic acid, and phytanic acid in fibroblasts, with normal results. The peroxisomes also had a normal appearance. A summary of laboratory investigations is shown in table 2. Patient 3 (V-4). This man is now 43 years old and still

working as a sailor. Poor hearing was noticed from childhood, and he now uses hearing aids in both ears. Cataract was diagnosed in his 20s and surgery performed at the ages of 25 and 28 years. He had his first consultation with a neurologist at age 38, at which stage he was complaining of mild unsteadiness and upper limb tremor that was present on action. Examination showed normal eye movements, normal tone and reflexes apart from absent ankle reflexes. His left plantar reflex was inverted and there was an upper limb intention tremor, mostly on the left. Neurologic examination 6 years later showed similar findings except that all of his reflexes were more difficult to elicit, his gait was clearly spastic and ataxic, and both plantar responses were extensor. Due to reduced night vision, he was referred for ophNeurology 72

January 6, 2009

23

Table 2

Results of investigations Patient V-1

Patient V-2

Patient V-4

Muscle biopsy

Normal

Normal

ND

MR/CT of brain

Normal

Normal

Mild cerebellar atrophy

ERG

Abnormal

Abnormal

Borderline abnormal

EEG

Nonspecific changes*

Normal

ND

ECG

Normal

Normal

ND

Phytanic/pristanic acid†

Normal/normal

Normal/normal

Normal/ND

Very-long-chain fatty acids‡

Normal

Normal

Normal

ND

Normal

ND

ND

Normal

ND

Vitamin E

ND

ND

Normal

CSF

Protein 0.67 g/L

Protein 0.74 g/L

ND

Enzymes and metabolites

Peroxisomal ␣-oxidation

§

Peroxisomal ␤-oxidation㥋 ¶

Lymphocytes 3/␮L

Lymphocytes 9/␮L

AFP/immunoglobulins#

ND

Normal levels

ND

Arylsulphatase**

ND

Normal

ND

Galactosylceramidase**

ND

Normal

ND

␤-Galactosidase**

ND

Normal

ND

Bile acids†

Normal

Normal

ND

Metabolic screening††

ND

Normal level

ND

SCA7‡‡

No mutation

No mutation

ND

Friedreich ataxia§§

ND

Normal

ND

DNA analyses





ATPase 6

No mutation

ND

ND

ATPase 8

No mutation

ND

ND

*EEG at age 42 showed some bilateral frontotemporal delta activity, but no focal changes. † Levels measured in plasma. ‡ Very-long-chain fatty acids ⫽ C26, C24, C22. All were measured in V-1 and V-2 but only C26 in V-4. § Oxidation of phytanic acid measured in fibroblasts.
Oxidation of C26 and pristanic acid measured in fibroblasts. Also, normal immunoblot profiles for both peroxisomal acylCoA oxidase and peroxisomal thiolase 1. ¶ Level measured in serum. # ␣-Fetoprotein and IgG, IgM, IgA electrophoresis. **Measured in lymphocytes. †† Organic acids and amino acids in urine and serum; nucleotides (HPLC). ‡‡ Test for CAG-expansion. §§ Test for GAA-expansion in the FXN gene.

This includes the 8993 T⬎G mutation (NARP). ND ⫽ not done.

thalmologic evaluation. Inspection showed no retinal pigment abnormalities, but ERG showed borderline normal values both for cone and rod function. The results of EMG and nerve conduction studies showed a demyelinating motor and sensor peripheral neuropathy; e.g., motor velocities median/ulnar 27–28 m/s (amplitude 4.7/7.6 mV) and tibial/peroneal 19 –21 m/s (amplitude 6/3.7 mV). Chronic neurogenic changes were seen in the distal leg muscles. MRI showed minor cerebellar atrophy. Results of biochemical investigations are given in table 2. Linkage analysis. The initial genome-wide scanning

with microsatellite markers revealed three regions 24

Neurology 72

January 6, 2009

with the following positive lod scores: 1.82 (chromosome 3q), 1.34 (chromosome 19q), and 1.19 (chromosome 20, spanning the centromere). Due to the low density of markers, we did not expect high lod scores in this first analysis. Fine mapping of these regions excluded all other candidate regions except the one on chromosome 20 (IBD). The extra markers used for fine-mapping and an extended pedigree (with inbreeding loops) were included in a new linkage analysis. The analysis identified a shared haplotype (IBD) in the three affected in the interesting region of chromosome 20, with a maximum lod score of 6.33. All the

Table 3

Physical distances are given according to NCBI MapViewer version 36.2.10

Sequenced candidate genes Function10

No. of exons

NFS1

Mitochondrion metabolism

14

ACSS1 (ACAS2L)

Lipid synthesis and energy generation

14

COX4I2

Cytochrome c oxidase, subunit 4, isoform 2

5

BCL2L1

Regulates electric and osmotic homeostasis of mitochondria

3

C20orf52

Membrane protein

2

Gene Mitochondrial function

Peroxisomal function PXMP4

4

Motor proteins and microtubuli MAPRE1

Microtubule binding

7

KIF3B*

Microtubule motor (knock out mice)

9

DYNLRB1

Axon cargo transport

4

SNTA1

Neuromuscular junction/synaptogenesis/ dystrophin

8

SLC32A1†

GABA and glycine uptake into synaptic vesicles

2

EPB41L1

Binds dopamine receptors at the neuronal plasma membrane

26

DLGAP4

Guanyl kinase, signal molecule, postsynaptic density

17

Neurotransmitters and synapses

Signal pathways POFUT1

Fucosyltransferase, essential for NOTCH-signaling

8

ITGB4BP

Integrin ␤4 binding protein

4

Cell growth and neural differentiation CDK5RAP1

Phosphorylation of neurofilaments and tau

14

Lipid synthesis and energy generation (cytosolic enzyme)

20

Homology to neuropathy mutated gene

15

Lipid biosynthesis ACAS2 Peripheral nervous system NDRG3‡ Miscellaneous functions MANBAL

Mannosidase, ␤ A, lysosomal-like

TM9SF4

Transporter activity

4 17

MYL9

Myosin light chain 9, regulatory

3

MGC72104

Homology to FRG1 (FSHD-like)

10

APBA2BP

Amyloid-␤ precursor protein-binding, family A, member 2

13

*Homologous to the KIF1B-gene, mutated in CMT type 2A1.25 †Homologous to the SLC12A6-gene, mutated in peripheral neuropathy associated with agenesis of corpus callosum.26 ‡Homologous to the NDRG1-gene, mutated in CMT type 4D.27

affected (but not their healthy siblings) were homozygous in this region, spanning 15.96 Mb (9.88 cM) (figure). This region was flanked by the markers D20S477 on 20p (22.36 Mb from pter) and D20S107 on 20q (38.32 Mb from pter).

Sequencing of candidate genes. The candidate region

contains 216 genes, including predicted genes and pseudogenes.10 We sequenced the coding regions and flanking intron segments for 23 of these (table 3), without detecting detrimental sequence variants. All genes known to have a function in mitochondria or peroxisomes were sequenced (table 3). Complex forms of hereditary neuropathy can be caused by mutations in genes involved in many different cellular processes. We therefore sequenced genes in our candidate region that are homologous to known genes associated with HMSN, such as NDRG3, KIF3B, and SLC32A1. We describe a novel neurologic disease with chromosomal location 20p11.21-q12 in which the main symptoms are early onset cataract, hearing loss, and neuropathy. The neuropathy is present from an early age (as evidenced by the presence of pes cavus and tendoachilles contracture), but symptoms of the sensorimotor demyelinating peripheral neuropathy develop later together with ataxia, retinitis pigmentosa, and pyramidal tract involvement. The disease develops slowly and appears not to affect cognition, such that the affected individuals are able to work until their motor disability becomes too severe. The clinical features found in our patients are reminiscent of Refsum disease, the main features of which are a demyelinating peripheral neuropathy, ataxia, and retinitis pigmentosa. Cardiomyopathy, sensorineural deafness, anosmia, and cataract are also common, with short metatarsals and ichthyosis being less common features. Another peroxisomal disorder, ␣-methylacyl-CoA racemase deficiency (OMIM #604489), can also cause neuropathy that can be either axonal or demyelinating, with pyramidal tract involvement, tremor, and epilepsy. Onset can be in childhood or adult life and affected individuals have elevated levels of both phytanic acid and pristanic acid in plasma.17 While our patients have many of the features found in Refsum disease, repeated analyses for phytanic acid and pristanic acid in plasma gave normal results. We also screened for bile acids and investigated the enzymatic capacity for oxidation of pristanic, phytanic, and hexacosanoic acid (normal findings in V-2), as some patients with Refsum-like disease have normal levels of these metabolites in plasma, despite having a defect in ␣-oxidation.16 Levels of very-long-chain fatty acids were normal in individuals V-2 and V-4, and the peroxisomes in individual V-2 had a normal appearance. In our canDISCUSSION

Neurology 72

January 6, 2009

25

didate region, we could only detect one gene with known peroxisomal function, PXMP4 (table 3), which we sequenced with normal findings. Taken together, our findings suggest that these patients do not have a disease caused by peroxisomal dysfunction. We also considered autosomal recessive forms of complex ataxia. Clinical findings suggested both sensory and cerebellar dysfunction was present and the degree of ataxia varied with V-1 having little ataxia and no clear signs of central affection, while her brother, V-2, has the most prominent ataxia together with signs of pyramidal tract involvement in the legs. V-5 also has a clear ataxia and cerebellar atrophy on MRI. Prior to embarking on linkage analysis, we excluded Friedreich ataxia, SCA 7 (despite recessive inheritance pattern), and vitamin E deficiency. Bile acids were normal in V-1 and ␣-fetoprotein and immunoglobulins were normal in V-2. Mitochondrial disease can manifest all the features described in our patients.18 Maternal inheritance was excluded in this family by the finding of a common male relative between the siblings and their third cousin (figure), but mutation in a nuclear gene was still a possibility. Nevertheless, before the family connections were finally identified, muscle biopsy was performed in two individuals and the NARP syndrome (OMIM#551500) excluded. Furthermore, all genes in the candidate region having a function that could be related to mitochondria (NFS1, ACSS1, COX4I2, BCL2L1, C20orf52) were sequenced with normal results. Gait ataxia and tremor can also occur in disorders primarily manifesting peripheral nerve disease, e.g., Roussy-Levy syndrome.19 Pyramidal signs and cranial nerve involvement have also been described in patients with mutations in genes important for Schwann cell function, such as the PMP22-, GJB1or MPZ-genes.20-23 Mutations in different types of connexins have been shown to cause symptoms such as peripheral neuropathy, deafness, and cataract,24 but no connexin-genes were found in the candidate region. We searched the region 20p11.21-q12 for homologues to genes known to cause different complex forms of hereditary neuropathy (table 3). The kinesins and those with microtubule or ciliary function were particularly interesting, as defects in ciliary function also are associated with retinitis pigmentosa. However, having sequenced 23 genes in the candidate region without finding a mutation, we decided to report the clinical characterization and the locus of this novel disease, as studying additional families is one way to refine the locus. We recognize, however, that direct sequencing does not reveal all possible causative mutations, including deep intronic 26

Neurology 72

January 6, 2009

mutations affecting splicing, or mutations in regulatory sequences. Thus, we cannot exclude the possibility that malfunction in one of the investigated genes still may be the cause of the disease. Genetic characterization of this complex disease would be particularly important, since it may give new insight into the pathology of a diversity of peripheral and central neurologic symptoms, as well as cataract. We suggest naming the disorder PHARC, an acronym that describes the major features of polyneuropathy, hearing loss, ataxia, retinitis pigmentosa, and cataract. ACKNOWLEDGMENT The authors thank the patients and their families for participating in this study and J.S. Bringsli, I.B. Tjelflaat, S. Erdal, and G. Matre for technical assistance.

Received February 6, 2008. Accepted in final form June 12, 2008.

REFERENCES 1. Nelis E, Cruts M, Wouters H. The mutation database of inherited peripheral neuropathies. Available at: http:// www.molgen.ua.ac.be/CMTmutations/default.cfm. Accessed September 2, 2007. 2. Niemann A, Berger P, Suter U. Pathomechanisms of mutant proteins in Charcot-Marie-Tooth disease. NeuroMol Med 2006;8:217–241. 3. Klein CJ. The inherited neuropathies. Neurol Clin 2007; 25:173–207. 4. Dubourg O, Azzedine H, Verny C, et al. Autosomalrecessive forms of demyelinating Charcot-Marie-Tooth disease. NeuroMol Med 2006;8:75–85. 5. Refsum S. Heredoataxia hemeralopica polyneuritiformis. Nord Med 1945;28:2682–2685. 6. Mihalik SJ, Morrell JC, Kim D, Sacksteder KA, Watkins PA, Gould SJ. Identification of PAHX, a Refsum disease gene. Nat Genet 1997;17:185–189. 7. van den Brink DM, Brites P, Haasjes J, et al. Identification of PEX7 as the second gene involved in Refsum disease. Am J Hum Genet 2003;72:471–477. 8. Lander E, Botstein D. Homozygosity mapping: a way to map human recessive traits with the DNA of inbred children. Science 1987;236:1567–1570. 9. Genin E, Todorov AA, Clerget-Darpoux F. Optimization of genome search strategies for homozygosity mapping: influence of marker spacing on power and threshold criteria for identification of candidate regions. Ann Hum Genet 1998;62:419–429. 10. NCBI Mapviewer. Available at: http://www.ncbi.nlm.nih. gov/mapview/online. Accessed September 2, 2007. 11. O’Connell JR, Weeks DE. PedCheck: a program for identification of genotype incompatibilities in linkage analysis. Am J Hum Genet 1998;63:259–266. 12. Mukhopadhyay N, Almasy L, Schroeder M, Mulvihill WP, Weeks DE. Mega2: data-handling for facilitating genetic linkage and association analyses. Bioinformatics 2005;21:2556–2557. 13. Gudbjartsson DF, Jonasson K, Frigge ML, Kong A. Allegro, a new computer program for multipoint linkage analysis. Nat Genet 2000;25:12–13.

14.

15.

16.

17.

18. 19.

20.

Sobel E, Sengul H. Multipoint estimation of identity-bydescent probabilities at arbitrary positions among marker loci on general pedigrees. Hum Hered 2001;52:121–131. Wijsman EM, Rothstein JH, Thompson EA. Multipoint linkage analysis with many multiallelic or dense diallelic markers: Markov Chain-Monte Carlo provides practical approaches for genome scans on general pedigrees. Am J Hum Genet 2006;79:846–858. Jansen G, Waterham H, Wanders RJ. Molecular basis of Refsum disease: sequence variations in phytanoyl-CoA hydroxylase (PHYH) and the PTS2 receptor (PEX7). Hum Mutat 2004;23:209–218. Ferdinandusse S, Denis S, Clayton PT, et al. Mutations in the gene encoding peroxisomal alpha-methylacyl-CoA racemase cause adult-onset sensory motor neuropathy. Nat Genet 2000;24:188–191. Chinnery PF, Howell N, Andrews RM, Turnbull DM. Clinical mitochondrial genetics. J Med Genet 1999;36:425–436. Auer-Grumbach M, Strasser-Fuchs S, Wagner K, Korner E, Fazekas F. Roussy-Levy syndrome is a phenotypic variant of Charcot-Marie-Tooth syndrome IA associated with a duplication on chromosome 17p11.2. J Neurol Sci 1998; 154:72–75. Plante´-Bordeneuve V, Guiochon-Mantel A, Lacroix C, Lapresle J, Said G. The Roussy-Le´vy family: from the original description to the gene. Ann Neurol 1999;46:770–773.

21.

22.

23.

24.

25.

26.

27.

Thomas PK, Marques Jr. W, Davis M, et al. The phenotypic manifestations of chromosome 17p11.2 duplication. Brain 1997;120:465–478. Abrams CK, Oh S, Ri Y, Bargiello TA. Mutations in connexin 32: the molecular and biophysical bases for the X-linked form of Charcot-Marie-Tooth disease. Brain Res Rev 2000;32:203–214. Szigeti K, Saifi G, Armstrong D, Belmont J, Miller G, Lupski J. Disturbance of muscle fiber differentiation in congenital hypomyelinating neuropathy caused by a novel myelin protein zero mutation. Ann Neurol 2003;54:398– 402. Wei C-J, Xu X, Lo CW. Connexins and cell signaling in development and disease. Annu Rev Cell Dev Biol 2004; 20:811–838. Zhao C, Takita J, Tanaka Y, et al. Charcot-Marie-Tooth disease type 2A caused by mutation in a microtubule motor KIF1Bbeta. Cell 2001;105:587–597. Howard HC, Mount DB, Rochefort D, et al. The K-Cl cotransporter KCC3 is mutant in a severe peripheral neuropathy associated with agenesis of the corpus callosum. Nat Genet 2002;32:384–392. Kalaydjieva L, Gresham D, Gooding R, et al. N-myc downstream-regulated gene 1 is mutated in hereditary motor and sensory neuropathy-Lom. Am J Hum Genet 2000; 67:47–58.

AAN CME: Quick, Convenient, Smart. The AAN makes earning your continuing medical education (CME) credits more convenient than ever with a host of unparalleled CME opportunities. Whether you choose online, print, or classroom, rest assured that AAN CME is designed by top experts in neurology specifically to help you fulfill your Maintenance of Certification requirements and stay current in the field. Quick and convenient has never been so smart. • Neurology Online CME • Continuum: Lifelong Learning in Neurology® • Quintessentials® • Online CME Tracker • 2009 Winter Conference, Lake Buena Vista, FL • 2009 AAN Annual Meeting, Seattle, WA • More Learn more at www.aan.com/cme.

Neurology 72

January 6, 2009

27

A novel ALS2 splice-site mutation in a Cypriot juvenile-onset primary lateral sclerosis family Nikolay Mintchev, MSc Eleni ZambaPapanicolaou, MD Kleopas A. Kleopa, MD Kyproula Christodoulou, PhD

Address correspondence and reprint requests to Dr. Kyproula Christodoulou, Neurogenetics Department, The Cyprus Institute of Neurology and Genetics, 6 International Airport Avenue, Ayios Dhometios, 2370 Nicosia, Cyprus [email protected]

ABSTRACT

Background: Primary lateral sclerosis (PLS) is a rare neurodegenerative disease that affects the upper motor neurons of the CNS. Juvenile-onset PLS (JPLS) is inherited in an autosomal recessive mode and is also found in sporadic cases. A consanguineous Cypriot family with three affected individuals presenting with JPLS was identified and studied.

Methods: Patients were clinically evaluated and samples were taken from consenting family members. All available family members were genotyped and linkage analysis at marker loci spanning the wider region of the ALS2 gene was performed. Selected exons of the ALS2 gene were sequenced and RNA analysis was performed using available lymphoblastoid cell lines from the proband.

Results: All affected individuals presented in the second year of life with progressive upper motor neuron dysfunction, affecting both bulbar and extremity muscles. Severity was variable, with two of the patients remaining ambulatory in the second and fifth decade of life while the third one was never able to walk. A novel ALS2 homozygous c.2980-2A⬎G mutation at the splice acceptor site of intron 17 was identified and its effect was confirmed at the RNA level. Conclusions: This novel ALS2 splice-site mutation is causing the loss of exon 18 in the transcript which results in a frameshift after exon 17. This frameshift most probably introduces a stop codon seven amino acids further down the new reading frame (p.993fsX7) and is expected to lead to a premature stop in exon 19 thus leading to a truncated protein after translation. Neurology® 2009;72:28–32 GLOSSARY ALS ⫽ amyotrophic lateral sclerosis; AR ⫽ autosomal recessive; bp ⫽ base pair; CMAP ⫽ compound muscle action potential amplitudes; IAHSP ⫽ infantile-onset ascending hereditary spastic paraplegia; JALS ⫽ juvenile-onset ALS; JPLS ⫽ juvenileonset PLS; NCS ⫽ nerve conduction studies; ND ⫽ not done; PLS ⫽ primary lateral sclerosis; SSEP ⫽ somatosensory evoked potentials; UMN ⫽ upper motor neurons; VEP ⫽ visual evoked potentials.

Primary lateral sclerosis (PLS) is a rare progressive paralytic disorder caused by the degeneration of the upper motor neurons (UMN) and the corticospinal and corticobulbar tracts of the motor cortex. PLS was first described by Erb in 1875 as a clinical syndrome of spastic weakness of the legs with mild spread to the arms in the absence of muscular atrophy. Erb later described pathologic findings of severe degeneration of the corticospinal tracts with sparing of the anterior horn cells. PLS is clinically distinct but closely related to amyotrophic lateral sclerosis (ALS). In ALS, degeneration of both upper and lower motor neurons is observed, whereas in PLS degeneration is confined to the UMN.1,2 ALS may also be differentiated from PLS by the presence of denervation or reinnervation on electromyography or muscle biopsy studies. Juvenile-onset PLS (JPLS) presents in either sporadic cases3 or in autosomal recessive (AR) familial cases.1,4,5 ALS2 gene mutations were identified in JPLS families1,6 but not in adult-onset PLS.7,8 While genetic heterogeneity has been reported for JPLS,1 ALS2 gene mutations have also been identified in other juvenile-onset AR disorders that are clinically similar but distinct from JPLS. Supplemental data at www.neurology.org From The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus. Disclosure: The authors report no disclosures. 28

Copyright © 2009 by AAN Enterprises, Inc.

Figure

Pedigree of the Cypriot JPLS family 5901

and their relations were established thereafter in different sessions. A total of eight individuals from the family consented and participated in the effort to identify the family disease gene mutation. Detailed clinical histories were obtained in all affected individuals and neurologic examination was performed. Standard nerve conduction studies were performed in all patients, and needle EMG in one of them.

Molecular genetic analyses. Blood samples were obtained after informed consent from individuals IV-6, V-1, V-2, V-3, V-4, VI-1, VI-2, and VI-3. DNA was extracted using standard salting out procedures. Since the only candidate locus for our JPLS family was the ALS2 locus, we investigated the family for linkage to a wider region on chromosome 2 that includes the ALS2 locus, using already available marker loci. All available individuals were genotyped at microsatellite polymorphic marker loci D2S1391, D2S1384, and D2S434, following previously described methodology.13

Linkage analyses. Linkage analysis was performed using the LINKAGE package of programs.14 Lod scores (Z) were calculated under an autosomal recessive inheritance model and a disease allele frequency of 1 in 10,000. Two-point lod scores between the disease in the family and each tested marker locus were calculated using the MLINK program. Multipoint lod scores were calculated using the LINKMAP program and the fixed map of loci D2S1391-14 cM-D2S1384-15 cM-D2S434. Sequence analysis. Genomic DNA sequencing of the ALS2

PCR and agarose gel electrophoresis-based mutation detection results are shown below the corresponding individual. A 487 base pair (bp) DNA fragment is amplified which is normally digested by the BfaI restriction endonuclease into three bands of 335 bp, 86 bp, and 66 bp. The ALS2 c.2980-2A⬎G mutation abolishes a BfaI restriction endonuclease site thus resulting in two bands of 401 bp and 86 bp. Homozygous normal individuals (VI-2) have three bands of 335 bp, 86 bp, and 66 bp, homozygous mutant individuals (VI-3, V-3, and V-4) have two bands of 401 bp and 86 bp, and heterozygous mutation carrier individuals (VI-1, V-1, V-2, and IV-6) have four bands of 401 bp, 335 bp, 86 bp, and 66 bp. JPLS ⫽ juvenile-onset primary lateral sclerosis.

These include juvenile-onset ALS (JALS)1,6,9 and infantile-onset ascending hereditary spastic paraplegia (IAHSP).10-12 We hereby report our findings in a consanguineous Cypriot JPLS family. A novel ALS2 splice-site mutation has been identified by direct sequencing at the genomic DNA level and further proved by sequencing of patient RNA. METHODS Subjects and samples. Family 5901 was a six-generation consanguineous kindred, originating from the Eastern part of the island of Cyprus, with three affected individuals in two different generations (figure). Patients of the two nuclear families were separately referred to the Cyprus Institute of Neurology and Genetics for clinical evaluation and diagnosis

gene was performed on the proband DNA. PCR primers were designed to amplify all the exons with known mutations in the Mediterranean and Middle East regions (table e-1 on the Neurology® Web site at www.neurology.org). PCR reactions were carried out using Ampli-Taq (Roche Diagnostics) and standard reaction mixtures. PCR products were purified with QIAquick PCR purification kit (QIAGEN) and sequenced in both directions using the CEQ DTCS kit and the Beckman Coulter CEQ analyser according to the manufacturer’s protocol. Sequence traces were automatically compared with the normal ALS2 gene sequence as listed in the GenBank database (Accession: NC_000002, Region: 202273522..202353983, Version: NC_000002.10, GI: 89161199 of 03 March 2008), using the CEQ8000 investigator software.

Family mutation detection. All available family members were analyzed for the identified mutation in order to obtain direct evidence of the mutation event and its cosegregation with the disease in the family. A 487 bp fragment encompassing the ALS2 exon 18 and boundary sequences was amplified by PCR, digested by the BfaI restriction endonuclease (New England Biolabs), and run on a 2% agarose gel.

Transcript study. Total RNA from a lymphoblastoid cell line of the proband and a control was extracted using the QIAGEN RNeasy kit (QIAGEN). Reverse transcription from isolated RNA was performed using the Protoscript First strand cDNA synthesis kit (New England Biolabs) with oligo-dT primers and according to the kit’s manual. The second step was performed using primers ALS2-16F (5=-CTCCACGCACCATGTTTTC3=) and ALS2-21R (5=-ACCATGACCATGACGCATA-3=), thus amplifying the region between exons 16 and 21 of the alsin gene’s cDNA. The PCR protocol was as follows: initial denaturation at 94°C for 2 minutes, then 35 cycles at 94°C for 30 seconds, 64°C for 90 seconds, and 72°C for 1 minute and a final elongation at 72°C for 5 minutes. PCR products were analyzed on a 1.5% agarose gel with ethidium bromide staining, then Neurology 72

January 6, 2009

29

Table 1

Clinical and laboratory features of the patients with juvenile-onset primary lateral sclerosis

Age, y/sex Age at onset, y Age at wheelchair, y Onset of bulbar weakness Onset of leg spasticity

Patient V-3

Patient V-4

Patient VI-2

55/M

42/F

16/M

2

2

2 50

2

Still ambulatory

3

2

2

2

2

2

Clinical findings Pseudobulbar palsy

⫹

⫹

⫹

Spastic quadriparesis

⫹

⫹

⫹

Extensor plantar responses

⫹

⫹

⫹

Brisk reflexes

⫹

⫹

⫹

Conjugate saccadic gaze paresis

⫹

⫹

⫹

Mild muscle atrophy

—

—

⫹

Fasciculations

—

—

—

EMG

ND

ND

Lack of muscle denervation

NCS

Normal (mildly reduced CMAPs)

Normal

Normal

Brain imaging

ND

Normal brain CT

ND

Evoked potential studies

ND

Normal VEP, SSEP

ND

Laboratory findings

ND ⫽ not done; NCS ⫽ nerve conduction studies; CMAP ⫽ compound muscle action potential amplitudes; VEP ⫽ visual evoked potentials; SSEP ⫽ somatosensory evoked potentials.

gel-purified (NucleoSpin Extract II, Clontech) and sequenced as described above. RESULTS Clinical features. All affected individuals presented in the second year of life with progressive motor dysfunction, affecting both bulbar and extremity muscles. The clinical and laboratory features of the patients are included in table 1. Detailed case reports of the three patients with JPLS are included in appendix e-1.

Genetic analysis. We tested our JPLS family for linkage to the ALS2 locus and found evidence for linkage with a maximum two-point lod score of 1.24 at recombination fraction 0 between the disease in the family and polymorphic marker locus D2S1384 (table 2). This result was further improved to a multipoint lod score of 1.5 at locus D2S1384 by multipoint linkage analysis (data not shown). Sequence analysis of the proband DNA at selected exons of the ALS2 gene revealed a novel homozygous c.2980-2A⬎G mutation at the splice acceptor site of intron 17 (figure e-1). To verify the cosegregation of the mutation with the disease we performed sequencing of the concerned genomic region for the rest of the available family members and we confirmed it by BfaI endonuclease restriction as30

Neurology 72

January 6, 2009

Table 2

Linkage investigation of our juvenileonset primary lateral sclerosis family at the ALS2 region LOD score values at ␪

Marker

0.01

0.05

0.1

0.2

D2S1391

⫺1.67

0.0

⫺0.23

0.26

0.33

0.25

D2S1384

1.24

1.20

1.02

0.83

0.49

D2S434

0.95

0.91

0.78

0.64

0.39

Two-point lod score values obtained between the disease in family 5901 and each marker locus are presented.

say (figure) since the mutation abolishes a BfaI recognition site. A mutation in an acceptor splice-site will usually result in either the use of a cryptic splice-site situated in the same intron or the next exon, or in an alternative splicing excluding at least exon 18 from the processed transcript. We performed an in silico study to define which of the above hypotheses was the most probable. We proceeded to an automated splicing mutation analysis by information theory.15,16 The results confirmed abolishment of the normal acceptor splice site in intron 17 of the ALS2 gene and the possible creation of a new cryptic acceptor splice site situated one base pair upstream of the natural one. The predicted new cryptic splice site had a 19.6-fold increase in its Ri but it was still significantly lower than the Ri value of the next natural splice site in intron 18 (data not shown). In order to determine whether the change in the acceptor splice-site causes a frameshift or an alternative splicing event we amplified cDNA by reverse transcription assay from total RNA extracted from the proband and a control lymphoblastoid cell line. The target cDNA sequence of the alsin gene was amplified using primers spanning exons 17, 18, 19, and 20 and the product was sequenced. Results of the proband clearly show the absence of exon 18 in the mRNA sequence of the ALS2 gene resulting from alternative splicing (figure e-2) as compared to the control. Absence of exon 18 results in a frameshift after exon 17 which most probably introduces a stop codon seven amino acids further down the new reading frame (p.993fsX7) and is expected to lead to a premature stop in exon 19 thus leading to a truncated protein after translation. DISCUSSION We present the clinical and genetic findings in a consanguineous family with JPLS caused by a novel ALS2 splice-site mutation. This is one of the very few genetically characterized JPLS families reported to date, and expands further the phenotypic elements of this rare disorder. The clinical features in the affected individuals are typical for

the JPLS phenotype as described previously,1,4,5 although some variations are noticeable: in all of our patients onset was during the second year of life, but the ability to walk was not lost in the second year of life in the two male patients. Although they developed progressive gait dysfunction beginning in early childhood, they remained ambulatory until the age of 50 in the first case or at least until adolescence in the second case. The former case is rather unusual and such late onset of wheelchair dependency has not been previously reported in JPLS. In contrast, his younger sister was never able to walk, indicating that significant phenotypic variability can be found even within the same JPLS family. Similar phenotypic variability has been noted in patients with JPLS, since some of these children are never able to walk on their own, while others walk on time but lose their ability to walk independently by the first decade of life.17 Slowly progressive uncomplicated signs of upper motor neuron disease were prominent in all patients along with gradual loss of speech production, while their cognitive function was preserved. As in previous JPLS families,4 all of our patients exhibited prominent conjugate saccadic gaze paresis, which is therefore a prominent feature of the JPLS phenotype. Furthermore, needle EMG performed in one of the patients showed no evidence of denervation to suggest lower motor neuron involvement as seen in JALS.1,6,9,18 Evoked potential studies and brain imaging were normal in another patient, excluding other disorders. In addition, bulbar involvement was prominent from the onset of the disease in all of our patients, similar to other families with JPLS,4,5 and in contrast to IAHSP patients.19 ALS2 is the only gene known to be involved in the development of autosomal recessive forms of three early-onset neurodegenerative diseases: JALS, JPLS, and IAHSP. Twelve different mutations of the alsin gene causing these diseases have been reported thus far1,2,6,9-12,20,21 but the correlation between the genotype and the observed clinical picture remains unclear. Most of these mutations result in a premature stop codon in the transcript thus creating a truncated protein lacking its carboxy-terminal part, which is most probably unstable.22 The ALS2 gene is located on chromosome 2q33 and consists of 34 exons, the first of which is noncoding. ALS2 is ubiquitously expressed but alsin is found in a low abundance even in alsin enriched neural tissues.22 The strongest expression of ALS2 is found in the brain tissue.6 ALS2 is reported to produce at least two splice variants1 resulting in both a long (6.5 kilobase) and a short (2.6 kilobase) transcript that produce a long (1,657 amino acids) and a short (396 amino acids) form of the encoded protein—alsin.

The long form of alsin has several predicted domains, which are found to be crucial for its function. An amino-terminally situated region presents homology with the RCC1 (regulator of chromatin condensation 1), a known GEF (guanine exchange factor) domain for the Ran family of small GTPases.23 Along with this region, there are two other predicted regions in the alsin sequence with Rho-GEF activity: a PH (pleckstrin homology) and a DH (Db1 homology) domain,24 and a carboxy-terminally situated VPS9 (vacuolar protein sorting 9) domain, which has a Rab5 guanine nucleotide exchange activity.25 There are also seven MORN (membrane occupation and recognition nexus) repeats, which suggest an association of alsin with intracellular membranes. Both MORN repeats and the VPS9 domain are important for the Rab5-GEF activity.26 We hereby present evidence of an alternative splicing event in the ALS2 mRNA, resulting from a c.2980-2A⬎G mutation in the acceptor splice-site in intron 17 of the gene. This leads to the loss of exon 18 in the transcript and to a frameshift creating a stop codon in exon 19. The translated protein alsin thus lacks its carboxy-terminal part and is probably unstable.22 The missing part of the protein comprises most of the MORN motifs, the VPS9 domain and a domain responsible for its homo-oligomerization. Those three domains are essential for alsin’s Rab5GEF activity and its function in endosome dynamics.26 It has also been shown previously that a protein lacking the VPS9 domain is nonfunctional27 and that this domain co-operates with the MORN motifs in the activation of the Rab5 GTPases.26 It has been suggested previously that, since most of the mutations in the ALS2 gene cause the production of a C-terminally truncated protein, the loss of the Rab5GEF activity of alsin might be the primary cause for JALS, JPLS, and IAHSP.28 Our results fully support this hypothesis. Received June 5, 2008. Accepted in final form September 18, 2008.

REFERENCES 1. Yang Y, Hentati A, Deng HX, et al. The gene encoding alsin, a protein with three guanine-nucleotide exchange factor domains, is mutated in a form of recessive amyotrophic lateral sclerosis. Nat Genet 2001;29:160–165. 2. Panzeri C, De Palma C, Martinuzzi A, et al. The first ALS2 missense mutation associated with JPLS reveals new aspects of alsin biological function. Brain 2006;129:1710– 1719. 3. Grunnet ML, Leicher C, Zimmerman A, Zalneraitis E, Barwick M. Primary lateral sclerosis in a child. Neurology 1989;39:1530–1532. 4. Lerman-Sagie T, Filiano J, Smith DW, Korson M. Infantile onset of hereditary ascending spastic paralysis with bulbar involvement. J Child Neurol 1996;11:54–57. Neurology 72

January 6, 2009

31

5.

Gascon GG, Chavis P, Yaghmour A, et al. Familial childhood primary lateral sclerosis with associated gaze paresis. Neuropediatrics 1995;26:313–319. 6. Hadano S, Hand CK, Osuga H, et al. A gene encoding a putative GTPase regulator is mutated in familial amyotrophic lateral sclerosis 2. Nat Genet 2001;29:166–173. 7. Brugman F, Eymard-Pierre E, van den Berg LH, Wokke JH, Gauthier-Barichard F, Boespflug-Tanguy O. Adultonset primary lateral sclerosis is not associated with mutations in the ALS2 gene. Neurology 2007;69:702–704. 8. Dupre N, Valdmanis PN, Bouchard JP, Rouleau GA. Autosomal dominant primary lateral sclerosis. Neurology 2007;68:1156–1157. 9. Kress JA, Kuhnlein P, Winter P, et al. Novel mutation in the ALS2 gene in juvenile amyotrophic lateral sclerosis. Ann Neurol 2005;58:800–803. 10. Eymard-Pierre E, Yamanaka K, Haeussler M, et al. Novel missense mutation in ALS2 gene results in infantile ascending hereditary spastic paralysis. Ann Neurol 2006;59: 976–980. 11. Gros-Louis F, Meijer IA, Hand CK, et al. An ALS2 gene mutation causes hereditary spastic paraplegia in a Pakistani kindred. Ann Neurol 2003;53:144–145. 12. Devon RS, Helm JR, Rouleau GA, et al. The first nonsense mutation in alsin results in a homogeneous phenotype of infantile-onset ascending spastic paralysis with bulbar involvement in two siblings. Clin Genet 2003;64: 210–215. 13. Christodoulou K, Kyriakides T, Hristova AH, et al. Mapping of a distal form of spinal muscular atrophy with upper limb predominance to chromosome 7p. Hum Mol Genet 1995;4:1629–1632. 14. Lathrop GM, Lalouel JM, Julier C, Ott J. Multilocus linkage analysis in humans: detection of linkage and estimation of recombination. Am J Hum Genet 1985;37:482–498. 15. Nalla VK, Rogan PK. Automated splicing mutation analysis by information theory. Hum Mutat 2005;25:334–342. 16. Rogan PK, Faux BM, Schneider TD. Information analysis of human splice site mutations. Hum Mutat 1998;12: 153–171. 17. Bertini E E-PE, Boespflug-Tanguy O, Yamanaka K, Cleveland D. ALS2-related disorders In: GeneReviews at GeneTests: Medical Genetics Information Resource (data-

base online). Updated 21 October 2005, cited 28 October 2007. 18. Shaw PJ. Genetic inroads in familial ALS. Nat Genet 2001;29:103–104. 19. Lesca G, Eymard-Pierre E, Santorelli FM, et al. Infantile ascending hereditary spastic paralysis (IAHSP): clinical features in 11 families. Neurology 2003;60:674–682. 20. Eymard-Pierre E, Lesca G, Dollet S, et al. Infantile-onset ascending hereditary spastic paralysis is associated with mutations in the alsin gene. Am J Hum Genet 2002;71: 518–527. 21. Hadano S, Kunita R, Otomo A, Suzuki-Utsunomiya K, Ikeda JE. Molecular and cellular function of ALS2/alsin: implication of membrane dynamics in neuronal development and degeneration. Neurochem Int 2007;51:74–84. 22. Yamanaka K, Vande Velde C, Eymard-Pierre E, Bertini E, Boespflug-Tanguy O, Cleveland DW. Unstable mutants in the peripheral endosomal membrane component ALS2 cause early-onset motor neuron disease. Proc Natl Acad Sci USA 2003;100:16041–16046. 23. Bischoff FR, Ponstingl H. Catalysis of guanine nucleotide exchange on Ran by the mitotic regulator RCC1. Nature 1991;354:80–82. 24. Rossman KL, Der CJ, Sondek J. GEF means go: turning on RHO GTPases with guanine nucleotide-exchange factors. Nat Rev Mol Cell Biol 2005;6:167–180. 25. Carney DS, Davies BA, Horazdovsky BF. Vps9 domaincontaining proteins: activators of Rab5 GTPases from yeast to neurons. Trends Cell Biol 2006;16:27–35. 26. Otomo A, Hadano S, Okada T, et al. ALS2, a novel guanine nucleotide exchange factor for the small GTPase Rab5, is implicated in endosomal dynamics. Hum Mol Genet 2003;12:1671–1687. 27. Topp JD, Gray NW, Gerard RD, Horazdovsky BF. Alsin is a Rab5 and Rac1 guanine nucleotide exchange factor. J Biol Chem 2004;279:24612–24623. 28. Kunita R, Otomo A, Mizumura H, et al. Homooligomerization of ALS2 through its unique carboxylterminal regions is essential for the ALS2-associated Rab5 guanine nucleotide exchange activity and its regulatory function on endosome trafficking. J Biol Chem 2004;279: 38626–38635.

No Charge for Color Figures Neurology® is committed to presenting data in the most descriptive way for the benefit of our readers. To make possible the publication of a greater number of color figures, we have elimated our color figure charges to authors.

32

Neurology 72

January 6, 2009

Long-term trends in carpal tunnel syndrome

R. Gelfman, MD L.J. Melton III, MD B.P. Yawn, MD P.C. Wollan, PhD P.C. Amadio, MD J.C. Stevens, MD

Address correspondence and reprint requests to Dr. Russell Gelfman, College of Medicine, Mayo Clinic, Rochester, MN 55905 [email protected]

ABSTRACT

Objective: To assess temporal trends in carpal tunnel syndrome (CTS) incidence, surgical treatment, and work-related lost time.

Methods: Incident CTS and first-time carpal tunnel release among Olmsted County, Minnesota, residents were identified using the medical records linkage system of the Rochester Epidemiology Project; 80% of a sample were confirmed by medical record review. Work-related CTS was identified from the Minnesota Department of Labor and Industry.

Results: Altogether, 10,069 Olmsted County residents were initially diagnosed with CTS in 1981–2005. Overall incidence (adjusted to the 2000 US population) was 491 and 258 per 100,000 person-years for women vs men (p ⬍ 0.0001) and 376 per 100,000 for both sexes combined. Adjusted annual rates increased from 258 per 100,000 in 1981–1985 to 424 in 2000 –2005 (p ⬍ 0.0001). The average annual incidence of carpal tunnel release surgery was 109 per 100,000, while that for work-related CTS was 11 per 100,000. An increase in young, working-age individuals seeking medical attention for symptoms of less severe CTS in the early to mid-1980s was followed in the 1990s by an increasing incidence in elderly people.

Conclusions: The incidence of medically diagnosed carpal tunnel syndrome (CTS) accelerated in the 1980s. The cause of the increase is unclear, but it corresponds to an epidemic of CTS cases resulting in lost work days that began in the mid-1980s and lasted through the mid-1990s. The elderly present with more severe disease and are more likely to have carpal tunnel surgery, which may have significant health policy implications given the aging population. Neurology® 2009;72:33–41 GLOSSARY CI ⫽ confidence interval; CTS ⫽ carpal tunnel syndrome; MESA ⫽ Marshfield Epidemiologic Study Area.

Carpal tunnel syndrome (CTS) is a common condition with potentially high social and economic costs, especially if it requires surgical treatment or interferes with one’s ability to work.1-4 Several studies have investigated the incidence of CTS in the general population, and rates appear to vary by study location and methodology employed.5-10 Despite this, studies generally show an increasing temporal trend, the explanation for which is unclear. Since our earlier study of CTS incidence in Rochester, Minnesota, from 1961 to 1980,5 the prevalence of personal CTS risk factors, such as obesity and diabetes, has increased in the general population.11-13 In addition, possible extrinsic CTS risk factors have increased as a result of greater labor productivity, general awareness, and more use of computers in industry, offices, and homes.14-17 Because of these changes, as well as the influence of different CTS definitions among studies, we updated the previous Rochester study through 2005 using the resources of the Rochester Epidemiology Project and expanded it to include all Olmsted County, Minnesota, residents.

From the Departments of Physical Medicine & Rehabilitation (R.G.), Health Sciences Research (L.J.M.), Orthopedics (P.C.A.), and Neurology (J.C.S.), College of Medicine, Mayo Clinic; and Department of Research (B.P.Y., P.C.W.), Olmsted Medical Center, Rochester, MN. Supported by a grant (R01-AR30582) from the NIH, US Public Health Service. This publication was made possible by Grant 1 UL1 RR024150 from the National Center for Research Resources (NCRR), a component of the NIH, and the NIH Roadmap for Medical Research. Its contents are solely the responsibility of the authors and do not necessarily represent the official view of NCRR or NIH. Information on NCRR is available at http://www.ncrr.nih.gov/. Information on Reengineering the Clinical Research Enterprise can be obtained from http://nihroadmap.nih.gov. Disclosure: The authors report no disclosures. Copyright © 2009 by AAN Enterprises, Inc.

33

The objectives were to identify temporal trends in the incidence of medically diagnosed CTS, the utilization of surgical treatment for CTS, and work-related lost time due to CTS. METHODS The Rochester Epidemiology Project medical record linkage system allows near complete ascertainment of diagnosed illnesses in the Olmsted County population.18 Following approval by the Mayo Clinic and Olmsted Medical Center institutional review boards, we identified new cases of carpal tunnel syndrome in all Olmsted County residents who had a diagnosis coded to rubric 357.2 (H-ICDA-8) or 354.0 (ICD-9) during the study period. To qualify as an incident case, the patient had to reside in Olmsted County for 1 year prior to the initial diagnosis (to exclude immigrants moving to the County for CTS care). In our earlier study, additional diagnostic categories (e.g., various peripheral neuropathies, nerve injuries, and selected other conditions) were screened to assure complete ascertainment of cases, but this laborious process yielded only 34 otherwise unidentified cases out of 1,016 total cases of CTS.5 Similarly, other investigators using electronic case identification with medical record confirmation found few cases of CTS assigned to ICD-9 diagnosis codes other than 354.0.6 Based on this shared experience, additional diagnostic categories were not reviewed as part of this study. Records also were not counted or reviewed of 712 potential cases (7%) who had not provided authorization to use their medical records for research.19 Because of the lack of a diagnostic gold standard, variations in clinical presentation, and differences in the diagnostic criteria used by different medical practitioners, administrative data may overestimate the incidence of CTS identified by ICD-9 code 354.0.20,21 Due to the large number of cases, one of the authors (R.G.) reviewed data collected by trained nurse abstractors from a random sample of the charts for criteria recommended for epidemiologic studies of CTS.22 Of 194 charts reviewed, 131 (68%) met symptom criteria for a diagnosis of classic/probable CTS, defined as numbness, tingling, burning, or pain in at least two of digits 1, 2, or 3. Another 25 met criteria for possible CTS, defined as numbness, tingling, burning, or pain in at least one of digits 1, 2, or 3; 38 did not specify the location of symptoms. Thus, 156 cases (80%) met symptom quality and location criteria for CTS.22 The confirmation rate was 94%, 76%, 81%, 72%, and 86%, for each respective quinquennium. Altogether, 113 (58%) had an electrodiagnostic study (EMG); of these, 88 (45% of the whole sample and 78% of those tested) had a study result consistent with median neuropathy at the wrist (figure 1). Administrative rates were not adjusted based on these results. Annual incidence (rate per 100,000 person-years) was estimated by dividing the number of new CTS cases observed by the entire population of Olmsted County (linear interpolation of decennial census figures from 1981 to 2000 with extrapolation through 2005), assuming everyone to be at risk.23 Rates were directly standardized to the age and sex distribution of the US population in 2000. The 95% confidence intervals (CIs) around these rates were estimated assuming a Poisson error distribution. A Poisson regression analysis of the crude incidence rates was used to assess their association with gender, age (considered as a class predictor variable, categorized as 0 –59, 60 – 69, 70 –79, and 80 or more years), and time period of diagnosis (using the midpoints of the 5-year periods: 1981–1985, 1986 –1990, 1991–1995, 1996 –2000, and 2001–2005). In a similar fashion, incidence rates for first-time carpal tunnel release operations and work-related CTS were estimated over 34

Neurology 72

January 6, 2009

the same period. The incidence (⬃utilization) of carpal tunnel release was determined by counting the number of operations electronically identified from the surgical index of the Rochester Epidemiology Project database, which contains a record of all such procedures performed in Olmsted County. The rates of work-related CTS were obtained by counting all incident cases of work-related CTS occurring among Olmsted County residents that resulted in more than 3 days of lost work time between 1981 and 2005; this was provided by the Minnesota Department of Labor and Industry from data routinely collected from employers or insurers.

A total of 10,069 Olmsted County residents were diagnosed with CTS for the first time in 1981–2005, of whom 6,897 were women and 3,172 were men. The overall age- and sex-adjusted incidence of CTS was 376 per 100,000 person-years (95% CI, 369 –384), but was much greater (p ⬍ 0.0001) in women (491 per 100,000 person-years; 95% CI, 479 –502) than men (258 per 100,000 person-years; 95% CI, 249 –268). The women-to-men ratio of CTS cases was 2.2:1, and of comparably adjusted incidence rates, was 1.9:1. However, rates increased almost twofold over the study period, from an overall incidence of 258 per 100,000 person-years in 1981–1985 to 424 per 100,000 in 2001–2005 (p ⬍ 0.0001). The sharpest rise was seen in 1986 –1990, but rates continued to increase in each subsequent period (figure 2A). Age-adjusted annual incidence in women increased 161%, from 337 to 542 per 100,000 during the time of the study; rates for men rose by a similar 172%, from 177 per 100,000 person-years in the first quinquennium to 303 per 100,000 in the last. These changes were accompanied by complex shifts in age distribution (table 1). Generally, the most marked increases in CTS incidence were seen in younger age groups of both sexes in the first part of the study period and among older age groups in the final decades of study. In contrast to the trends for CTS diagnosis, firsttime carpal tunnel release surgery decreased slightly throughout the first four quinquennia (figure 2B). In 2001–2005, however, the utilization of this procedure increased, due mostly to increased rates of surgery in both men and women over 50 years of age. Detailed data are provided in table 2. Figure 2C shows the rates of work-related CTS, which increased dramatically between 1981–1985 and 1986 –1990 only to decline in the 1991–1995 quinquennium in men and in the 1996 –2000 quinquennium in women; rates remained relatively stable thereafter. This temporal pattern differed considerably from those observed for CTS diagnosis or surgery. RESULTS

DISCUSSION This is the longest study to date of trends in the incidence of medically diagnosed CTS

Figure 1

Symptom characteristics and EMG results of 156 patients with classic/probable or possible carpal tunnel syndrome (CTS) from review of a random sample of 194 charts

Thirty-eight of the charts did not reference finger location of symptoms and were excluded. Criteria for a positive nerve conduction study (NCS) include median palmar distal latency more than 2.3 msec, median-to-ulnar palmar latency difference exceeding 0.3 msec when the palmar latency was 2.2 msec or less, or a median antidromic sensory latency more than 3.6 msec with a normal ulnar antidromic sensory latency.

in the general population. We previously had documented a 1.4-fold increase in annual CTS incidence in this population, from 88 per 100,000 in 1961– 1965 to 125 per 100,000 in 1976 –1980.5 Rather than a true increase in CTS, the change was attributed to better recognition of CTS (detection bias) due to a gradual increase in awareness of the syndrome by medical professionals, the opening of a hand clinic in the community in 1967, and the introduction of more sensitive electrodiagnostic techniques, especially palmar median sensory stimulation after 1977.5 However, despite the fact that CTS has been very well known in this medical community since 1960,24 the present investigation reveals that the trend to increasing rates accelerated in more recent decades, reaching an overall age- and sex-

adjusted annual incidence of 424 per 100,000 in 2001–2005. This is consistent with other studies of CTS trends (table 3). Thus, the number of cases reportedly increased by approximately 90% in women and 145% in men between 1992 and 2001 in East Kent.8 In Sienna, CTS rates increased by 8% in women and 74% in men between 1991 and 1998,7 while in the United Kingdom generally, CTS increased by 13% for women and 35% for men between 1992 and 2000.9 Finally, in the Netherlands, the crude incidence of CTS in 1987 was 190 per 100,000 in women and 60 per 100,000 in men; in 2001, the rates were 280 and 90 per 100,000 in women and men.10 These trends may reflect a greater awareness of CTS among the general population, especially in the decades of the 1980s and 1990s, when Neurology 72

January 6, 2009

35

Figure 2

Age-adjusted (women, men) and age- and sex-adjusted (both sexes combined) incidence per 100,000 person-years for carpal tunnel syndrome diagnosis (A), carpal tunnel release surgery (B), and work-related carpal tunnel syndrome with lost work days (C), among Olmsted County, Minnesota, residents, 1981–2005

For details on the process of submitting a First Report of Injury form for work-related injuries, see www.doli.state.mn.us/ fr01info.html. 36

Neurology 72

January 6, 2009

articles on CTS began to appear in the popular press. For example, a search for articles containing the words “carpal tunnel syndrome” in The New York Times using ProQuest yields a total of 318 articles from 1981 to 2005; the number in each quinquennium during that time was 11, 43, 89, 103, and 72. Although rates were higher in women in the earlier Rochester study, the increase was somewhat greater for men so that the women:men ratio of ageadjusted incidence rates fell from 4.0:1 to 2.5:1 between 1961 and 1980. Likewise in the present study, the rise in CTS incidence was again somewhat greater in men so that the sex ratio fell to 1.8:1 in the last quinquennium. These ratios are similar to those reported in Canterbury (2.0:1)8 and the United Kingdom (2.5:1)9 but differ from those reported in Marshfield (1.1:1)6 and Sienna (4.1:1).7 The discrepancies are difficult to explain. One possibility is that CTS may be underestimated in men in some populations,25 perhaps because of the theory that men are less likely to seek care for symptoms.26 Since incidence rates have changed over time and no other study has looked at medically diagnosed CTS over such a long interval, it seems most appropriate to compare rates in individual quinquennia. Our incidence of 397 per 100,000 person-years from 1991 to 1995 is comparable to the rate found in the Marshfield Epidemiologic Study Area (MESA), but higher than in Huddersfield (table 3). The MESA rate from July 1991 to June 1993 was 377 per 100,000 person-years,6 and in the EMG clinic in Huddersfield only 47 per 100,000 from 1991 to 1993.8 Our incidence rate from 1996 to 2000 was 412 per 100,000 person-years. These rates are higher than in Sienna, Canterbury, the United Kingdom in general, and the Netherlands (table 3). The rates in Sienna were 269 per 100,000 person-years from 1991 to 19987; in Canterbury, 90 per 100,000 person-years from 1992 to 20018; in the United Kingdom generally, 136 per 100,000 person-years from 1992 to 20009; and in the Netherlands, 219 per 100,000 person-years in 2001.10 The use of administrative data containing all cases diagnosed in the community and the use of clinical criteria for confirmation of CTS in our study and the MESA study might explain the higher overall rates in comparison to some of the other studies, which were done in referral centers and required a confirmatory EMG.7,8 Although we would agree that a positive nerve conduction study increases the likelihood of a correct diagnosis, not all individuals with classic symptoms have abnormal nerve conduction studies.27 However, even after accounting for an 80% case confirmation rate in our study, the lower rates found in general practice in the United Kingdom and the Netherlands

Table 1

Incidence (per 100,000 person-years) of first episode of carpal tunnel syndrome diagnosis among residents of Olmsted County, Minnesota, 1981 through 2005, by gender and age group

Age group, y

1981–1985

1986 –1990

1991–1995

1996 –2000

2001–2005

All years

No.

No.

No.

No.

No.

No.

Rate

Rate

Rate

Rate

Rate

Rate

Women 26

34

26

33

14

17

32

37

28

30

126

30

20–29

127

271

221

494

247

575

225

543

206

477

1,026

468

30–39

172

434

339

723

423

848

387

773

318

599

1,639

684

40–49

137

507

253

784

367

933

414

868

458

848

1,629

813

50–59

142

698

153

702

195

757

277

882

418

1173

1,185

878

60–69

63

397

100

589

80

432

118

580

176

790

537

571

70–79

65

516

70

524

68

470

109

692

129

748

441

601

80 Total

32

367

53

517

49

417

95

719

85

583

314

536

764

309

1,215

460

1,443

508

1,657

540

1,818

544

6,897

480

Adjusted rate* (95% CI)

337 (313–362)

474 (447–501)

510 (483–536)

537 (511–563)

542 (517–567)

491 (479–502)

Men 80 Total

11

6

7

13

14

18

18

56

13

11

334

16

421

27

579

24

417

35

535

113

470

336

148

496

202

658

246

774

266

908

285

3172

235

Adjusted rate* (95% CI)

9

177

228

264

281

303

(157–197)

(207–249)

(244–285)

(261–301)

(283–323)

1,100

1,711

2,101

2,431

2,726

258 (249–268)

Both sexes Total Adjusted rate† (95% CI)

232 258

(242–274)

336 352

(335–369)

381 397

(371–404)

406 412

(396–429)

417 424

(411–443)

10,069

361 376

(369–384)

*Annual incidence per 100,000 age-adjusted to the 2000 US population. †Annual incidence per 100,000 age- and sex-adjusted to the 2000 US population. CI ⫽ confidence interval.

require some explanation.9,10 There may be a true difference in incidence between the countries, or the differences could reflect different attitudes on the part of patients regarding conditions that require a doctor visit, or in the accessibility of medical care. It is interesting that the highest incidence is in the United States, which is the only country among those mentioned that does not have universal health care coverage. One might expect that our rates would be lower if the differences were due to insurance status. Thus, our findings tend to support the hypothesis that national attitudes toward disease in the general population may explain at least some of the differences in medically attended incidence of CTS between countries.

What other factors might explain the increasing incidence over time? Our results would suggest that newer or more frequent diagnostic tests are not responsible since the methods for CTS diagnosis using nerve conduction studies remained relatively similar during the period of study, and our finding that 58% of the cases selected for chart review had been referred for an EMG is similar to the 61% figure in the 1976 –1980 quinquennium of the previous Rochester study.5 An increasing presentation of milder cases deserves consideration. Our chart review estimated the true incidence (using symptom criteria) at around 80% of the rate obtained from the administrative diagnostic data; rates of clinical confirmation in each quinquennium were 94%, 76%, 81%, 72%, and 86%, with no clear trend to indicate a Neurology 72

January 6, 2009

37

Table 2

Incidence (per 100,000 person-years) of first episode of carpal tunnel release among residents of Olmsted County, Minnesota, 1981 through 2005, by gender and age group

Age group, y

1981–1985

1986 –1990

1991–1995

1996 –2000

2001–2005

All years

No.

No.

No.

No.

No.

No.

Rate

Rate

Rate

Rate

Rate

Rate

Women 2

80 Total

22

252

22

215

23

196

28

212

35

239

130

222

311

126

327

124

331

116

363

118

570

171

1,902

132

Adjusted rate* (95% CI)

142 (126–159)

132 (118–147)

119 (106–132)

118 (106–130)

171 (157–185)

138 (132–144)

Men 2

3

3

4

2

2

20–29

20

50

16

40

21

53

6

15

7

17

70

49

30–39

24

63

29

64

36

74

29

59

32

61

150

114

40–49

16

60

34

110

31

83

40

88

61

118

182

158

50–59

17

86

25

114

29

114

47

158

67

202

185

219

60–69

29

217

19

129

29

175

29

156

40

194

146

196

70–79

21

278

18

211

20

200

19

161

47

354

125

266

4

122

10

263

8

172

9

157

20

306

51

219

133

59

154

63

176

66

183

63

275

86

921

68

80 Total Adjusted rate* (95% CI)

72 (59–84)

76 (63–88)

4

4

74 (63–86)

1

1

69 (59–79)

12

3

96

79

(85–108)

(74–84)

845

2823

Both sexes Total

444

Adjusted rate† (95% CI)

94 108

(98–118)

481

94

507

92

104 (95–114)

546

97 (89–106)

91 94

(86–102)

129 134

(125–143)

101 109

(105–113)

*Annual incidence per 100,000 age-adjusted to the 2000 US population. †Annual incidence per 100,000 age- and sex-adjusted to the 2000 US population. CI ⫽ confidence interval.

systematic change in criteria for diagnosis over time. Conversely, the increase in CTS incidence in Canterbury was accompanied by a decline in the electrophysiologic severity of new cases, indicating that at least some of their increase might be due to diagnosing milder cases of median neuropathy.8 However, increasing CTS incidence in the earlier years of this study was not accompanied by increasing rates of carpal tunnel release, possibly suggesting that the cases were not severe enough to warrant surgery. Carpal tunnel surgery utilization in Olmsted County in 1986 –1990 (104 per 100,000 personyears; 95% CI, 95–114) was comparable to the rate reported in Ontario in 1988 (109 per 100,000)28 and slightly less than the 155 per 100,000 figure reported 38

Neurology 72

January 6, 2009

in Wisconsin in the early 1990s.29 In 1993, crude rates in Maine varied by location from 82 to 287 per 100,000, with a state average of 144 per 100,000.30 Increasing surgical rates were seen in the later years of this study and reflect the increasing number of elderly individuals presenting with CTS, who appear to have more advanced disease. The Canterbury investigators also noted that elderly individuals tended to present with more severe disease.8 These data again lend support to the hypothesis that public attitudes about CTS, and the symptoms associated with it, may have changed, resulting in more patients presenting for care from a given reservoir of disease. While the increase in diagnosis may simply result from increased ascertainment of a common disor-

Table 3

Comparison of population studies on the incidence of carpal tunnel syndrome diagnosis Women Time period

No.

Men Rate*

Rochester, MN5

1961–1980

MESA, WI6

1991–1993

Sienna, Italy7

1991–1998

Canterbury, UK8

1992–2001

4,295

118

Huddersfield, UK8

1991–1993

—

1992–2000

United Kingdom Netherlands10

9

798

Both sexes

No.

Rate*

No.

Rate†

172

218

61

219

401

180

353

399

377

2,504

426

638

104

3,142

269

1,950

60

6,245

90

—

34

590

47

60

1,016

118

16,344

192

6,514

78

22,858

136

1987

87

240

26

77

113

162

2001

511

326

161

105

672

219

Olmsted County, MN (present study) 1981–1985

764

337

336

177

1,100

258

1986–1990

1,215

474

496

228

1,711

352

1991–1995

1,443

510

658

264

2,101

397

1996–2000

1,657

537

774

281

2,431

412

2001–2005

1,818

544

908

303

2,726

424

1981–2005

6,897

491

3,172

258

10,069

376

*Annual incidence per 100,000 age-adjusted to the 2000 US population. †Annual incidence per 100,000 age- and sex-adjusted to the 2000 US population. MESA ⫽ Marshfield Epidemiologic Study Area.

der,31 it is also possible that the increase could be due to an increased prevalence of known CTS risk factors, or the emergence of new ones.32 Compared to the incidence of CTS in Rochester in 1976 –1980,5 the higher rate seen in MESA over a decade later was felt to represent an actual increase in CTS, as it was presumed that the area had a higher proportion of workers in supposedly “at risk” occupations,6 as reviewed elsewhere.33 In addition, an apparent epidemic of work-related CTS resulting in lost work days began in the mid-1980s in Olmsted County and continued through the mid-1990s. Beginning in the late 1970s, there were dramatic increases in productivity in certain industries, and workers began noting an increase in problems involving pain and numbness in the hands.34 Strikes at meatpacking facilities led to articles in several prominent newspapers across the country that brought occupational CTS to national and international attention.14,35,36 Similar trends in productivity in offices increased awareness of the disorder among computer users.37 Interestingly, the trend in CTS resulting in lost work days is very different from trends seen with medically attended CTS and surgical cases in the general population. We are unaware of any medical research explaining this, although the phenomenon has been attributed to occupational pseudo-illness.38 The stigmatization of the condition in the press may play a role.39 Possibilities for reduced CTS mentioned in the lay press include ergonomic changes, early recog-

nition of symptoms with work modification before they become reportable problems, lack of faithful reporting of musculoskeletal disorders by employers, and the changing priorities of unions.40 These possibilities deserve further study because of the health implications for workers. A strength of this study was the use of a unique data system with a very long-term perspective. However, there were a number of corresponding limitations, including use of electronic case ascertainment and the exclusion of about 7% of potential cases because they had not authorized the use of their medical records for research.19 In addition, the study was conducted in a small community in the Midwest with a limited minority population, although the sociodemographic characteristics of the population resemble those of US whites generally except for overrepresentation of medical workers and a somewhat higher educational level.18 Notably, incidence rates for work-related CTS are underestimated: Due to ambiguities in determining the number of workers at risk, and the fact that all Olmsted County residents are at risk of developing CTS whether or not due to work, we used the whole population instead of the working population in the denominator. This allowed us to compare temporal trends directly with the CTS incidence and surgery rates but precluded reliable estimation of the actual incidence rate of CTS in the working population. Most significantly, we did not attempt to ascertain the prevalence of Neurology 72

January 6, 2009

39

CTS in the population who did not seek the attention of a physician. This group could have sought care from providers not in our database, such as chiropractors, or not sought medical attention at all. Thus, ultimately, we are unable to know whether the changes in incidence that we observed are due to a true change in the underlying condition, or simply a change in how patients and physicians interact concerning it. A new finding from this study was that, during the 2000 –2005 quinquennium, the incidence of CTS in younger people appeared to decrease, while the rate in older individuals appeared to increase. This older group also contributed disproportionately to the increasing incidence of carpal tunnel release operations. In other words, the older individuals seeking medical care for CTS appear to have more severe disease and are more likely to be candidates for carpal tunnel release operations as compared to younger individuals. This finding may have significant health policy implications given the growing elderly population.

9.

10.

11.

12.

13.

14.

15.

ACKNOWLEDGMENT The authors thank Brian Zaidman from the Minnesota Department of Labor & Industry for collecting and summarizing the work-related CTS statistics; Margary Kurland, Linda Paradise, Christine Pilon-Kacir, Maria Stracke, and Chris Parisi for abstracting chart data; and Mary Roberts for help in preparing the manuscript.

Received April 17, 1008. Accepted in final form September 23, 2008. REFERENCES 1. Palmer DH, Hanrahan LP. Social and economic costs of carpal tunnel surgery. Instr Course Lect 1995;44:167– 172. 2. Manktelow RT, Binhammer P, Tomat LR, Bril V, Szalai JP. Carpal tunnel syndrome: cross-sectional and outcome study in Ontario workers. J Hand Surg 2004;29A:307– 317. 3. Daniell WE, Fulton-Kehoe D, Chiou LA, Franklin GM. Work-related carpal tunnel syndrome in Washington state workers’ compensation: temporal trends, clinical practices, and disability. Am J Ind Med 2005;48:259–269. 4. Foley M, Silverstein B, Polissar N. The economic burden of carpal tunnel syndrome: long-term earnings of CTS claimants in Washington State. Am J Ind Med 2007;50: 155–172. 5. Stevens JC, Sun S, Beard CM, O’Fallon WM, Kurland LT. Carpal tunnel syndrome in Rochester, Minnesota, 1961 to 1980 Neurology 1988;38:134–138. 6. Nordstrom DL, DeStefano F, Vierkant RA, Layde PM. Incidence of diagnosed carpal tunnel syndrome in a general population. Epidemiology 1998;9:342–345. 7. Mondelli M, Giannini F, Giacchi M. Carpal tunnel syndrome incidence in a general population. Neurology 2002; 58:289–294. 8. Bland JD, Rudolfer SM. Clinical surveillance of carpal tunnel syndrome in two areas of the United Kingdom, 1991–2001. J Neurol Neurosurg Psychiatry 2003;74: 1674–1679. 40

Neurology 72

January 6, 2009

16. 17. 18. 19. 20.

21.

22.

23.

24. 25.

26.

27.

28.

Latinovic R, Gulliford MC, Hughes RAC. Incidence of common compressive neuropathies in primary care. J Neurol Neurosurg Psychiatry 2006;77:263–265. Bongers FJM, Schellevis FG, van den Bosch WJHM, van der Zee J. Carpal tunnel syndrome in general practice (1987 and 2001): incidence and the role of occupational and non-occupational factors. Br J Gen Pract 2007;57:36–39. Mokdad AH, Serdula MK, Dietz WH, Bowman BA, Marks JS, Koplan JP. The spread of the obesity epidemic in the United States, 1991–1998. JAMA 1999;282:1519– 1522. Ogden CL, Carroll MD, Curtin LR, McDowell MA, Tabak CJ, Flegal KM. Prevalence of overweight and obesity in the United States, 1999 –2004. JAMA 2006;295: 1549–1555. CDC. Quickstats: number of persons with diagnosed diabetes and number of ambulatory care visits related to diabetes: United States, 1997–2004. MMWR 2006;55: 825. Brogmus GE, Sorock GS, Webster BS. Recent trends in work-related cumulative trauma disorders of the upper extremities in the United States: an evaluation of possible reasons. J Occup Environ Med 1996;38:401–411. Village J, Rempel D, Teschke K. Musculoskeletal disorders of the upper extremity associated with computer work: a systematic review. Occup Ergonomics 2005;5:205–218. Freeman L. Job creation and the emerging home computer market. Monthly Labor Review 1996;119:46–56. Hipple S, Kosanovich K. Computer and internet use at work in 2001. Monthly Labor Review 2003;126:26–35. Melton LJ III. History of the Rochester Epidemiology Project. Mayo Clin Proc 1996;71:266–274. Melton LJ III. The threat to medical-records research. N Engl J Med 1997;337:1466–1470. Spinner RJ, Bachman JW, Amadio PC. The many faces of carpal tunnel syndrome. Mayo Clin Proc 1989;64:829– 836. Graham B, Dvali L, Regehr G, Wright JG. Variations in diagnostic criteria for carpal tunnel syndrome among Ontario specialists. Am J Ind Med 2006;49:8–13. Rempel D, Evanoff B, Amadio PC, et al. Consensus criteria for the classification of carpal tunnel syndrome in epidemiologic studies. Am J Public Health 1998;88: 1447–1451. Bergstralh EJ, Offord KP, Chu C-P, Beard CM, O’Fallon WM, Melton LJ III. Calculating incidence, prevalence and mortality rates for Olmsted County, Minnesota: An update. Technical Report Series No. 49, Mayo Clinic, Rochester, 1992. Amadio PC. The Mayo Clinic and carpal tunnel syndrome. Mayo Clin Proc 1992;67:42–48. Padua L, Aprile I, Caliandro P, Tonali P. Is the occurrence of carpal tunnel syndrome in men underestimated? Epidemiology 2001;12:369. Treaster DE, Burr D. Gender differences in prevalence of upper extremity musculoskeletal disorders. Ergonomics 2004;47:495–526. Witt JC, Hentz JG, Stevens JC. Carpal tunnel syndrome with normal nerve conduction studies. Muscle Nerve 2004;29:515–522. Liss GM, Armstrong C, Kusiak RA, Gailitis MM. Use of provincial health insurance plan billing data to estimate

29.

30.

31.

32. 33.

carpal tunnel syndrome morbidity and surgery rates. Am J Ind Med 1992;22:395–409. Hanrahan LP, Higgins D, Anderson H, Smith M. Wisconsin occupational carpal tunnel syndrome surveillance: the incidence of surgically treated cases. Wis Med J 1993; 92:685–689. Keller RB, Largay AM, Soule DN, Katz JN. Maine carpal tunnel study: small area variations. J Hand Surg 1998;23A: 692–696. Atroshi I, Gummesson C, Johnsson R, Ornstein E, Ranstam J, Rose´n I. Prevalence of carpal tunnel syndrome in a general population. JAMA 1999;282:153–158. Haase J. Carpal tunnel syndrome: a comprehensive review. Adv Tech Stand Neurosurg 2007;32:175–249. Palmer KT, Harris EC, Coggon D. Carpal tunnel syndrome and its relation to occupation: a systematic literature review. Occup Med 2007;57:57–66.

34.

35.

36. 37. 38. 39.

40.

Demby AE. Occupation and Disease: How Social Factors Affect the Conception of Work-Related Disorders. New Haven: Yale University Press; 1996. Novek J. The labour process and workplace injuries in the Canadian meat packing industry. Canad Rev Sociol Anthrop 1992;29:17–37. Rachleff P. The living legacy of the IWW: Austin, Minnesota. Working USA 2005;8:555–563. Brody JE. Epidemic at the computer: hand and arm injuries. The New York Times March 3, 1992. Bell DS. Epidemic occupational pseudo-illness: the plague of acronyms. Curr Rev Pain 2000;4:324–330. Anthony S, Lozano-Calderon S, Ring D. Stigmatization of repetitive hand use in newspaper reports of hand illness. Hand 2008;30–33. Fitzgerald M. Sprain and pain wane: carpal tunnel syndrome scare over? Editor Publisher 2007;140:6–9.

Calling All New and International Members! Don’t miss these FREE AAN Annual Meeting events designed just for you: • New Member Information Session Sunday, April 26 / 5:00 p.m. to 6:00 p.m. Learn about the AAN, its resources and benefits, and network with Academy leaders. • International Attendee Summit Monday, April 27 / 7:00 a.m. to 9:00 a.m. Meet Academy leaders and make your voice heard on matters most important to you. Learn more at www.aan.com/specialevents.

Save with Exclusive AAN Member Benefits! Looking for the best value in home, term-life, or medical malpractice insurance for you and your family? How about competitive rates on credit cards or simplified payment processing? Enjoy these and more exclusive benefits, already included with your AAN membership, in the AAN Partners Program. We’ve done the leg work to find the best values on quality products and services. We’ve negotiated these offerings so low that they could save MORE than the cost of your membership! Take advantage of ALL of your Academy benefits today; visit www.aan.com/pp08 to get started!

Neurology 72

January 6, 2009

41

Frontal FDG-PET activity correlates with cognitive outcome after STN-DBS in Parkinson disease E. Kalbe, PhD J. Voges, MD T. Weber, MD M. Haarer, MSc Psy S. Baudrexel, MD J.C. Klein, MD J. Kessler, PhD V. Sturm, MD W.D. Heiss, MD R. Hilker, MD

Address correspondence and reprint requests to Dr. Elke Kalbe, Department of Neurology, University Hospital, Kerpener Str. 62, D-50937 Cologne, Germany [email protected]

ABSTRACT

Background: Inconsistent changes of cognitive functioning have been reported in patients with Parkinson disease (PD) with deep brain stimulation (DBS) of the subthalamic nucleus (STN). To investigate the underlying pathomechanisms, we correlated alterations of cognitive test performance and changes of neuronal energy metabolism in frontal basal ganglia projection areas under bilateral STN stimulation.

Methods: We conducted verbal fluency, learning, and memory tests and 18-fluorodeoxyglucose (FDG) PET in nine patients with PD with STN-DBS before and 6 months after surgery. Using coregistered MRI, postoperative changes of the normalized cerebral metabolic rates of glucose (nCMRGlc) in the dorsolateral prefrontal cortex (DLPFC), lateral orbitofrontal cortex (LOFC), ventral and dorsal cingulum (v/dACC), and in Broca area were determined and correlated with alterations of neuropsychological test results. Results: After surgery, highly variable changes of both cognitive test performance and frontal nCMRGlc values were found with significant correlations between verbal fluency and FDG uptake in the left DLPFC (Brodmann area [BA] 9, 46), left Broca area (BA 44/45), and the right dACC (BA 32). A decrease of nCMRGlc in the left OFC (BA 11/47) and dACC (BA 32) correlated with a decline of verbal learning. All patients showed reduced metabolic activity in the right anterior cingulate cortex after DBS. Baseline cognitive abilities did not predict verbal learning or fluency changes after surgery. Conclusions: These data show a significant linear relationship between changes in frontal 18fluorodeoxyglucose PET activity and changes in cognitive outcome after deep brain stimulation of the subthalamic nucleus (STN) in advanced Parkinson disease. The best correlations were found in the left frontal lobe (dorsolateral prefrontal cortex and Broca area). Baseline performance on cognitive tests did not predict cognitive or metabolic changes after STN electrode implantation. Neurology® 2009;72:42–49 GLOSSARY BA ⫽ Brodmann area; BDI ⫽ Beck Depression Inventory; BG ⫽ basal ganglia; CI ⫽ confidence interval; DBS ⫽ deep brain stimulation; DLPFC ⫽ dorsolateral prefrontal cortex; FDG ⫽ 18-fluorodeoxyglucose; LEDD ⫽ levodopa equivalent daily dose; LOFC ⫽ lateral orbitofrontal cortex; MDRS ⫽ Mattis Dementia Rating Scale; nCMRGlc ⫽ normalized cerebral metabolic rates of glucose; PD ⫽ Parkinson disease; RCI ⫽ Reliable Change Index; rCMRGlc ⫽ regional cerebral metabolic rate of glucose; STN ⫽ subthalamic nucleus; TE ⫽ echo time; TR ⫽ repetition time; v/dACC ⫽ ventral and dorsal cingulum; VOI ⫽ volume of interest.

Deep brain stimulation of the subthalamic nucleus (STN-DBS) is an effective long-term treatment for motor fluctuations and severe tremor in advanced Parkinson disease (PD).1 Although STN surgery is considered generally safe from a cognitive point of view,2 the individual neuropsychological outcome is hard to predict and may include relevant adverse effects in individual patients.3,4 Although severe cognitive deterioration under STN-DBS is rare,2 mild to moderate decline occurs in up to 40% of operated patients.4 Currently available data are inconsistent, reporting worsening to Supplemental data at www.neurology.org From the Departments of Neurology (E.K., T.W., M.H., J.K.) and Stereotaxy and Functional Neurosurgery (V.S.), University of Cologne; Department of Stereotactic Neurosurgery (J.V.), University of Magdeburg; Department of Neurology (S.B., J.C.K., R.H.), Goethe-University Frankfurt; and Max-Planck Institute for Neurological Research (W.D.H.), Cologne, Germany. Funded in part by the EC-FP6-project DiMI, LSHB-CT-2005-512146. Disclosure: The authors report no disclosures. 42

Copyright © 2009 by AAN Enterprises, Inc.

Table 1

Individual patient characteristics, clinical data, and medication before surgery and at time of the follow-up investigation

Patient no.

Age, y

Sex

Disease duration, y

MDRS baseline

1

61

M

8

141

2

62

M

15

3

57

M

10

4

53

M

5

62

F

6

71

7

65

8 9

BDI baseline

HY stage baseline

UPDRS III baseline*

UPDRS III follow-up†

LEDD baseline

LEDD follow-up

4

4

43

16

750

400

135

4

3

36

17

1,400

800

142

6

4

46

14

600

800

11

138

12

4

49

25

1,300

500

17

135

19

3

33

10

550

200

F

21

136

15

4

68

39

900

700

M

22

137

18

4

42

30

500

450

65

F

14

144

3

4

52

22

800

500

65

M

17

131

10

3

39

17

700

600

*Obtained at least 12 hours after cessation of antiparkinsonian medication (practically defined drug off). †Obtained at least 12 hours after beginning of STN stimulation (DBS-on) and at least 12 hours after cessation of antiparkinsonian medication (practically defined drug off). MDRS ⫽ Mattis Dementia Rating Scale; BDI ⫽ Beck Depression Inventory; HY ⫽ Hoehn/Yahr stage; UPDRS III ⫽ Unified Parkinson’s Disease Rating Scale Motor Score; LEDD ⫽ levodopa equivalent daily dose.

improvement of cognitive domains2,3,5-7 with impaired verbal fluency as the most frequent postoperative finding.2 The pathomechanism of cognitive decline in STN stimulated patients is largely unknown. The STN is a main relay station not only in motor but also in associative and limbic circuits of the basal ganglia (BG), both involved in the regulation of cognition and behavior.8 To which extent these loops are influenced by the long-term application of high-frequency electrical stimuli and whether this is related to cognitive changes is under debate. To address this question, we investigated nine patients with advanced PD before and after STN-DBS and correlated postoperative changes of verbal fluency, verbal learning, and verbal memory with alterations of frontal glucose metabolism in 18Fluorodeoxyglucose (FDG) PET. METHODS Subjects. After obtaining permission of the local ethics committee and written informed consent according to the declaration of Helsinki, nine patients with advanced PD and bilateral STN-DBS were enrolled in the study (six men, three women, age: 62.3 ⫾ 5.2 years, disease duration: 15 ⫾ 5 years, Hoehn and Yahr drug off scores: 3.7 ⫾ 0.5 [range: 3– 4], UPDRS III score in practically defined medication off: 45 ⫾ 10; table 1). All patients were treated in the Cologne outpatient movement disorders clinic. PD was diagnosed according to the UK PD Society Brain Bank criteria.9 Each patient fulfilled CAPSIT-PD criteria for surgical intervention in PD due to severe levodopa-associated on-off-fluctuations and dyskinesia refractory to medication.10 Dementia and depression were excluded before surgery with a cutoff value of 130 points for the Mattis Dementia Rating Scale (MDRS)11 and of 20 points for the Beck Depression Inventory (BDI).12 Bilateral STN electrodes

(Medtronic model 3389, Medtronic, Minneapolis, MN) and impulse generators (Kinetra, Medtronic GmbH) were implanted with intraoperative macrostimulation, stereotactic teleradiography, and repeated neurologic monitoring as described previously.13,14 The transfer of stereotactic x, y, z coordinates from intraoperative x-ray to treatment-planning MR images documented the localization of the most distal and of the active electrode pole with 1.5 mm contact length and 0.5 mm contact interspace in seven out of nine patients.13 The accuracy of a similar method for stereotactic implantation of radioactive seeds in brain tumors yielded a median difference of 0.6 mm for the x-axis, 0.6 mm for the y-axis, and 0.9 mm for the z-axis between the planned target and the final location of the implant.15 PD medication and DBS parameters were individually optimized in repeated programming sessions after surgery. Total dopaminergic treatment was calculated as the levodopa equivalent daily dose (LEDD) according to the following formula16: 1 mg pergolide ⫽ 1 mg lisuride ⫽ 1 mg pramipexole ⫽ 2 mg cabergoline ⫽ 5 mg ropinirole ⫽ 10 mg bromocriptine ⫽ 10 mg apomorphine ⫽ 20 mg dihydroergocryptine ⫽ 100 mg levodopa.

Neuropsychological testing. Neuropsychological tests were administered before electrode implantation (medication oncondition) and in the DBS on- and medication on-condition 6 months after surgery. Verbal fluency was tested with 1-minute letter word fluency tasks (letters S, K, or P).17 Verbal learning and long-term memory were examined with a word list learning paradigm (Memo Test18 or German version of the Rey Auditory Verbal Learning Test19). Standardization of test results was achieved by Z-transformation according to age-matched normative values. Postoperative changes of test performance were expressed as Z-score differences from follow-up to baseline and defined as improved (ⱖ0.5 SD), stable (between ⬍⫹0.5 SD and ⬎⫺0.5), or deteriorated (ⱕ⫺0.5 SD).

PET and MR imaging. We performed FDG-PET on an ECAT Exact HR scanner (Siemens-CTI, Knoxville, TN) 2 to 4 weeks before electrode implantation and in the DBS oncondition after surgery with a mean follow-up interval of 6 ⫾ 1 months. FDG-PET data were compared to those of 10 healthy age-matched controls (six men, four women, age 67 ⫾ 4 years). PD medication was withdrawn for at least 12 hours prior to each Neurology 72

January 6, 2009

43

PET scanning at baseline and follow-up (drug-off state). The patients’ clinical condition was monitored by an experienced neurologist during PET. Despite the presence of severe offperiod symptoms, no patient had severe tremor or off-period dystonia as a source of potential confound of cerebral FDG uptake. Before the examination began, short catheters were inserted into a cubital vein for injection and into a vein of the contralateral hand, which was subsequently kept in a thermostatcontrolled water bath at 44°C for arterialized venous blood sampling as described before.20 Following correction for scatter and attenuation, 370 MBq FDG were injected and six time frames of 10 minutes duration were acquired in three-dimensional data acquisition mode. Images were reconstructed by filtered back projection providing 47 contiguous transaxial image planes (slice thickness 3.1 mm) with reconstructed resolution of 5 mm (full width at half maximum).21 In addition, high-resolution MRI was performed before surgery (1.5 Tesla Magnetom, Siemens AG, Erlangen, Germany) with axial T2-weighted turbo spin-echo (repetition time [TR] 4,675 msec, echo time [TE] 100 msec) and T1-weighted spin-echo images (TR 19 msec, TE 4.6 msec) with a slice thickness of 2 mm and a matrix size of 512 ⫻ 512 pixels (pixel size 0.5 mm). In each study subject, the cortex was subdivided according to anatomic atlases into volumes of interest (VOIs) by outlining the appropriate anatomic structures in transversal MRI slices with interactive software (three-dimensional tool). VOIs were chosen according to their relevance for cognition and previously reported metabolic changes in patients with PD with bilateral STN-DBS.14 They included associative BG projection sites with the middle frontal gyrus, Brodmann area (BA) 9 and 46 (dorsolateral prefrontal cortex [DLPFC]), and the inferior frontal gyrus, BA 10 (lateral orbitofrontal cortex [LOFC]), as well as limbic BG projection sites with the inferior frontal gyrus orbital part, BA 11/47 (orbitofrontal cortex [OFC]) and the ventral (BA 24 [vACC]) and dorsal anterior cingulum (BA 32 [dACC]). A further VOI was placed in Broca region (inferior frontal gyrus triangular and opercular part, BA 44/45). This MRI-based VOI atlas was coregistered with the last four frames of each FDG scan in standard AC-PC position using standard software (MPI tool).22 The regional cerebral metabolic rate of glucose (rCMRGlc) was calculated with the autoradiographic model and a rate constant K1 adjusted to measured tissue FDG activity with a fixed lumped constant LC ⫽ 0.42.21 The LC is a conversion factor between FDG and glucose brain net uptake since FDG and glucose differ with regard to transport across the blood– brain barrier and phosphorylation through the initial step in the glycolysis. In order to compensate for individual differences of global brain activity, rCMRGlc values were normalized (nCMRGlc) by division with the global metabolic rate of glucose of the entire brain.23 Postoperative metabolic changes were expressed as nCMRGlc differences between baseline and follow-up PET scans and subdivided into three categories according to 1 SD of the controls’ mean (improved: ⬎0.5 SD, stable: between ⬍⫹0.5 and ⬎⫺0.5 SD, and deteriorated ⬍⫺0.5 SD).

Statistical analysis. All analyses were carried out with the SPSS software package (release 14.0.2, SPSS Inc., Chicago, IL). Parametric methods were used for variables after testing for normal distribution (Kolmogorov Smirnov test). For neuropsychological data, a two-way multivariate analysis of variance with the factors time (preoperative, postoperative) and cognitive domain (three stages with the domains verbal fluency, verbal learning, and verbal memory delayed recall) with repeated measures on both factors was computed. The Reliable Change Index (RCI)24 was calculated for each patient 44

Neurology 72

January 6, 2009

as a measure whether the observed changes in cognitive test results are meaningful or might be explained by test-retest variability and other factors independent from the intervention under investigation. The RCI was determined according to the following formula: (X2 ⫺ X1) ⫺ (M2 ⫺ M1)/SD with X1 as the observed baseline score, X2 the follow-up score, M1 and M2 the group means at baseline and follow-up, and SD as the SD of the group test-retest differences. According to a previous study using RCI values for the assessment of cognitive changes in patients with PD,25 a meaningful RCI was assumed for values outside of the 90% confidence intervals (CIs) of the RCI mean. Longitudinal clinical data and nCMRGlc values were compared with paired t test statistics. Neuropsychological and nCMRGlc difference scores were correlated with each other and with several preoperative variables (Pearson product moment correlation). The level of significance was set at p ⬍ 0.05.

Under effective STNDBS, a 47% reduction of the drug-off UPDRS motor score was observed (45 ⫾ 10 before vs 21 ⫾ 9 after surgery; p ⬍ 0.001). Mean DBS parameters were as follows: amplitude 3.6 ⫾ 0.4 V, impulse width 70.0 ⫾ 15.0 ␮s, frequency 132 ⫾ 7 Hz with monopolar cathodic stimulation in all electrodes. Mean coordinates of active electrode poles in relation to the midcommissural point were as follows: right hemisphere: x: 12.4 ⫾ 0.9, y: ⫺0.1 ⫾ 2.8, z: ⫺2.0 ⫾ 3.3; left hemisphere: x: ⫺13.0 ⫾ 1.2, y: ⫺0.3 ⫾ 1.6, z: ⫺1.8 ⫾ 3.9. The mean LEDD decreased from 833 ⫾ 319 mg before surgery (dose range: 500 –1,400 mg daily) to 550 ⫾ 197 mg at time of follow-up PET scans (dose range: 200–800 mg daily) (p ⫽ 0.021). Each patient continued on oral levodopa therapy after surgery. Dopamine agonists were additionally given in five out of nine patients (cabergoline 2–6 mg in four and pramipexole 0.54 mg in one) as well as amantadine (100 and 300 mg) in two patients. RESULTS Clinical outcome.

Neuropsychological testing. Baseline global dementia

and depression screening showed 138 ⫾ 4 points in the MDRS and 10 ⫾ 6 in the BDI. After STN electrode implantation, highly heterogeneous changes of cognitive performance most frequently in the verbal learning task were observed ranging from marked deterioration to improvement (table 2). The RCI values of patients with improved or deteriorated z-scores were outside of the 90% CI of the group mean in all patients in the verbal fluency and verbal memory domains as well as in four out of eight patients in verbal learning (table 2). MANOVA showed no significant effects for the factors time [F (df ⫽ 1) ⫽ 0.014, p ⫽ 0.910] and cognitive domain [F (df ⫽ 2) ⫽ 4.29, p ⫽ 0.061] and the interaction of both [F (df ⫽ 2) ⫽ 0.324, p ⫽ 0.733]. PET. After STN surgery, bilateral nCMRGlc reduc-

tion in the vACC (BA 24; p ⬍ 0.001 right, p ⬍ 0.05 left) and in the left dACC (BA 32; p ⬍ 0.05) was found. The individual postoperative nCMRGlc data showed a considerable variance with increased, un-

Table 2

Neuropsychological test results (Z-scores) of the patient group and individual patients before (t1) and after surgery (t2) Verbal fluency

Group mean SD

Verbal learning

t1

t2

⫺0.5

⫺0.7

Change

(1.5)

(1.4)

RCI

t1

t2

0.1

0.0

(2.0)

(2.0)

Verbal memory Change

RCI

⫺0.84

90% CI

⫺1.1

⫺0.4

Patient 2

⫺1.6

⫺0.8

Patient 3

1.2

1.9

Patient 4

0.3

⫺2.3

Deteriorated

Patient 5

⫺2.3

⫺1.9

Stable

Patient 6

0.7

⫺0.8

Deteriorated

Patient 7

⫺1.2

⫺0.4

Improved

Patient 8

1.9

0.6

Patient 9

⫺2.1

⫺2.1

Improved

⫺0.5

(1.7)

(2.2)

Change

RCI

⫺0.58

⫹1.00

0.85*

1.5

1.6

Improved

0.87*

⫺1.2

⫺0.3

Improved

1.01*

Improved

0.86*

1.5

2.1

Improved

0.73

⫺2.48* 0.61

t2

⫺0.6

⫺0.97

⫹0.72 Patient 1

t1

Stable

⫹0.69

0.20

1.5

0.1

Deteriorated

⫺3.2

0.3

Improved

0.4

⫺2.1

⫺1.3

Improved

0.74*

1.3

2.9

Improved

1.57*

⫺0.87 3.51*

⫺0.51

0.8

Stable

0.8

⫺0.4

Deteriorated

⫺1.35*

⫺2.5

⫺3.2

Deteriorated

⫺0.77*

⫺1.32*

⫺0.4

⫺2.0

Deteriorated

⫺1.54*

⫺1.3

⫺1.7

Stable

⫺0.51

1.03*

⫺1.4

⫺3.0

Deteriorated

⫺1.54*

⫺2.9

⫺2.9

Stable

⫺0.10

Deteriorated

⫺1.11*

Stable

⫺0.60

3.6

2.8

Deteriorated

⫺0.74

1.3

2.9

⫺0.7

⫺1.4

Deteriorated

⫺0.60

⫺0.8

⫺0.8

Improved

1.57* ⫺0.10

Stable

Individual changes of cognitive performance were calculated as Z-score differences (t2 ⫺ t1) and defined as improved (ⱖ0.5 SD), stable (between ⬍⫹0.5 and ⬎⫺0.5 SD), or deteriorated (ⱕ⫺0.5 SD). *Outside of the 90% confidence interval (CI) of mean Reliable Change Index (RCI).

changed, and decreased values in all VOIs reaching maximum heterogeneity in the left LOFC (BA 10: ⫺20.8% to ⫹12.4%) and in the left OFC (BA 11/ 47: ⫺17.9% to 14.0%; table 3). In contrast, unidirectional FDG uptake reduction was detected in each patient in the right and in six out of nine patients in the left vACC (BA 24). Correlation of postoperative neuropsychological and FDG-PET changes. Postoperative changes of verbal flu-

ency correlated with nCMRGlc alterations in the left DLPFC (BA 9: r ⫽ 0.67, p ⫽ 0.048; BA 46: r ⫽ 0.90, p ⫽ 0.001), left Broca area (BA 44/45: r ⫽ 0.85, p ⫽ 0.004), and right dACC (BA 32: r ⫽ 0.74, p ⫽ 0.024) (figure 1, and figures e-1 and e-2 on the Neurology® Table 3

Web site at www.neurology.org). A similar relationship was found between the verbal learning performance and FDG uptake in the left OFC (BA 11/47: r ⫽ 0.68, p ⫽ 0.045) and in the left dACC (BA 32: r ⫽ 0.69, p ⫽ 0.037) (figures e-3 and e-4). Patients with a clear deterioration of verbal fluency and verbal learning had a marked nCMRGlc decrease in every VOI compared to individuals with stable or even improved cognitive functions (figure 2). The latter showed an increased FDG uptake in most VOIs except for both cingulate areas (BA 24 and BA 32). Correlation of cognitive and metabolic changes with preoperative variables. A higher degree of baseline

motor impairment (UPDRS III drug-off scores) cor-

Mean group and individual STN-DBS–related changes of the normalized cerebral metabolic rate of glucose measured with FDGPET at follow-up (t2) minus baseline (t1) in nine patients with Parkinson disease Right hemisphere Group change (%)

Left hemisphere Individual change (n)

Group change (%)

Individual change (n)

VOI (BA)

Mean (SD)

Range

Improved

Stable

Deteriorated

Mean (SD)

Range

Improved

Stable

Deteriorated

9

⫺2.4 (7.1)

⫺11.5 ⫹ 9.1

3

1

5

⫺2.0 (10.4)

⫺14.3 ⫹ 12.0

4

2

3

10

0.3 (8.7)

⫺15.8 ⫹ 11.6

4

2

3

1.0 (10.6)

⫺20.8 ⫹ 12.4

3

4

2

46

⫺0.7 (7.2)

⫺9.9 ⫹ 13.7

2

3

4

0.1 (9.3)

⫺15.1 ⫹ 9.3

5

1

3

44/45

⫺1.8 (5.9)

⫺12.3 ⫹ 10.2

1

3

5

⫺0.9 (8.2)

⫺17.4 ⫹ 6.8

4

2

3

11/47

⫺1.8 (8.3)

⫺19.7 ⫹ 9.7

3

2

4

⫺1.6 (9.0)

⫺17.9 ⫹ 14.0

4

1

4

24

⫺7.5 (3.1)

⫺10.4 ⫺ 2.6

0

0

9

⫺5.2 (5.5)

⫺13.5 ⫹ 5.1

1

2

6

32

⫺2.4 (4.4)

⫺8.2 ⫹ 6.1

1

5

3

⫺3.1 (2.8)

⫺7.1 ⫹ 0.6

0

4

5

Individual changes were subdivided into three categories according to 1 SD of the controls’ mean: improved ⬎0.5 SD, deteriorated ⬍⫺0.5 SD, and stable for differences in between. The number of patients in each category is given. VOI ⫽ volumes of interest; BA ⫽ Brodmann area. Neurology 72

January 6, 2009

45

Figure 1

Correlations of changes in word fluency and region-specific regional cerebral metabolic rate of glucose (rCMRGlc)

STN-DBS–related changes of word fluency correlate with alterations of cerebral metabolic rates of glucose in the left DLPFC (BA 46) (r ⫽ 0.90, p ⫽ 0.001; A) and in the left Broca area (BA 44/45) (r ⫽ 0.85, p ⫽ 0.004; B).

related with postoperative nCMRGlc decrease in several VOIs: BA 10 (right: r ⫽ ⫺0.72, p ⫽ 0.028, left: r ⫽ ⫺0.80, p ⫽ 0.01), BA 44/45 (left: r ⫽ ⫺0.81, p ⫽ 0.008), BA 46 (left: r ⫽ ⫺0.72, p ⫽ 0.029), BA 47/11 (right: r ⫽ ⫺0.78, p ⫽ 0.012; left: r ⫽ ⫺0.97, p ⬍ 0.001). Preoperative UPDRS III drug-off values also correlated with verbal fluency decline after surgery (r ⫽ ⫺0.68, p ⫽ 0.045). In contrast, neuropsychological test performance including MDRS and BDI data at baseline, disease duration, baseline frontal FDG uptake values, LEDD reduction, and stereotactic coordinates of active electrode poles did not correlate with postoperative cognitive and metabolic changes (data not shown). The results of this study demonstrate that the heterogeneous outcome of verbal fluency and verbal learning performance in patients with PD with effective STN-DBS is closely linked to changes of neuronal glucose metabolism in associative and limbic frontal BG projection sites and in the left Broca area. In general, frontal deactivation was asso-

DISCUSSION

46

Neurology 72

January 6, 2009

ciated with worsening of cognitive function, whereas unchanged or increased glucose metabolism related to stable or even improved verbal fluency and verbal learning. Therefore, the functional integrity of the frontal cortex seems to be a reliable predictor for preserved cognitive functioning in patients with advanced PD with STN stimulation. We found a significant relationship between surgery-related changes of glucose uptake in the left DLPFC, Broca area, and right dACC and postoperative verbal fluency performance. This finding is in line with previous imaging studies in healthy subjects demonstrating activations in the same brain areas as neuronal correlates of verbal fluency.26,27 In addition, a PET study with 15-O labeled water showed that reduced cerebral blood flow within a left-sided frontotemporal network is associated with impaired verbal fluency under active STN-DBS.28 The cingulate cortices (bilateral vACC and left dACC) were the brain regions with the most obvious and significant metabolic deactivation after STNDBS. According to the so-called paradox of stereotactic surgery,29 these data suggest that STN stimulation not only facilitates the recruitment of movement-related prefrontal areas, but can also exert the opposite effect on associative and limbic BG projection sites. Our finding that the postoperative verbal learning performance correlated with metabolic activity in the left dACC corroborates the known importance of this part of the Papez circuit for attention to action30 and encoding new material in working memory.31 The cingulate BG loop was also associated with response inhibition32 and conflict monitoring33 in agreement with previous PET data showing decreased ACC activation during a response conflict (Stroop) task under bilateral STN stimulation.34 Moreover, the strong deactivation in the ventral and dorsal ACC might be associated with behavioral changes and with flattening of affect, apathy, and increased irritability, which were reported to occur in 5–10% of patients with PD with STNDBS.4 These behavioral disturbances can be interpreted as a loss of psychic self activation following lesions in the BG limbic loop which predominantly projects to the ACC.35 However, we cannot draw any conclusions on the clinical relevance of stimulation-related limbic hypometabolism in our study because we did not formally investigate affect and behavior. From a methodologic point of view, it has to be emphasized that our study design compared medication-off states during PET and medication-on conditions during neuropsychological testing. This certainly implicates some ambiguity whether postoperative metabolic and cognitive changes are due to

Figure 2

Correlations of changes in word fluency and regional cerebral metabolic rate of glucose (rCMRGlc)

STN-DBS–related change of normalized regional cerebral metabolic rate of glucose (nCMRGlc) in patients with Parkinson disease with improved (left panel), stable (middle panel), or deteriorated (right panel) postoperative test performance in the domains verbal fluency (A) and verbal learning (B). Changes of neuropsychological functioning were classified according to individual Z-score differences as follows: improved: difference of ⱖ0.5 SD, stable: change between ⬍⫹0.5 and ⬎⫺0.5 SD, deteriorated: difference of ⱕ⫺0.5 SD.

the surgical procedure (microlesional effect), current application (DBS), medication adaptation, or all factors together. However, this design was chosen from two reasons: the severe motor deficit in the drug-off state regularly prohibiting reliable neuropsychological testing in patients with advanced PD on the one hand and drug effects on brain metabolism as a poorly controllable confounder in FDG-PET neces-

sitating discontinuation of medication before scanning on the other hand. Since the postoperative LEDD reduction did not correlate with changes of neuropsychological test performance after surgery, we believe that both electrode placement and DBS current spread contribute more comprehensively than medication changes to the heterogeneous impact of STN-DBS on frontal lobe functioning. The Neurology 72

January 6, 2009

47

48

latter argues for a variable interference of DBS electrode implantation with anteromedial extramotor STN areas which are in close proximity of the nucleus’ motor region. From a clinical point of view, our data confirm previous findings that verbal fluency and learning are heterogeneously affected after STN-DBS, so far widely unpredictable before surgery. Our results suggest that a severe motor deficit in the preoperative drug-off state indicating advanced nigrostriatal degeneration is associated with the risk for frontal dysfunction and verbal fluency deterioration after STN electrode implantation. Future studies are needed to determine the clinical relevance of cognitive decline with respect to resulting constraints of quality of life and social capabilities in patients with STN stimulation. Valid predictive factors for the cognitive, affective, and behavioral outcome of STN-DBS on an individual basis have to be identified. Finally, the optimization of surgical electrode positioning is a pivotal challenge in order to restrict the stimulation effect on the dorsolateral motor STN.

10.

Received May 31, 2008. Accepted in final form September 18, 2008.

17.

REFERENCES 1. Krack P, Batir A, Van Blercom N, et al. Five-year follow-up of bilateral stimulation of the subthalamic nucleus in advanced Parkinson’s disease. N Engl J Med 2003; 349:1925–1934. 2. Parsons TD, Rogers SA, Braaten AJ, Woods SP, Troster AI. Cognitive sequelae of subthalamic nucleus deep brain stimulation in Parkinson’s disease: a meta-analysis. Lancet Neurol 2006;5:578–588. 3. Voon V, Kubu C, Krack P, Houeto JL, Troster AI. Deep brain stimulation: neuropsychological and neuropsychiatric issues. Mov Disord 2006;21(suppl 14):305–327. 4. Temel Y, Kessels A, Tan S, Topdag A, Boon P, VisserVandewalle V. Behavioural changes after bilateral subthalamic stimulation in advanced Parkinson disease: a systematic review. Parkinsonism Relat Disorders 2006;12:265–272. 5. Funkiewiez A, Ardouin C, Caputo E, et al. Long term effects of bilateral subthalamic nucleus stimulation on cognitive function, mood, and behaviour in Parkinson’s disease. J Neurol Neurosurg Psychiatr 2004;75:834–839. 6. Saint-Cyr JA, Trepanier LL, Kumar R, Lozano AM, Lang AE. Neuropsychological consequences of chronic bilateral stimulation of the subthalamic nucleus in Parkinson’s disease. Brain 2000;123:2091–2108. 7. Jahanshahi M, Ardouin CM, Brown RG, et al. The impact of deep brain stimulation on executive function in Parkinson’s disease. Brain 2000;123:1142–1154. 8. Alexander GE, Crutcher MD. Functional architecture of basal ganglia circuits: neural substrates of parallel processing. Trends Neurosci 1990;14:55–59. 9. Hughes AJ, Daniel SE, Kilford L, Lees AJ. Accuracy of clinical diagnosis of idiopathic Parkinson’s disease: a clinico-pathological study of 100 cases. J Neurol Neurosurg Psychiatry 1992;55:181–184.

18.

Neurology 72

January 6, 2009

11.

12.

13.

14.

15.

16.

19. 20.

21.

22.

23.

24.

25.

26.

27.

Defer GL, Widner H, Marie´ RM, Re´my P, Levivier M. Core assessment program for surgical interventional therapies in Parkinson’s disease (CAPSIT-PD). Mov Disord 1999;14:572–584. Mattis S. Dementia Rating Scale: Professional Manual. Odessa, FL: Psychological Assessment Resources, Inc., 1988. Beck AT, Hautzinger M, Bailer M, Worall H, Keller F. Beck-Depressions-Inventar (BDI). Go¨ttingen: Hogrefe; 1995. Voges J, Volkmann J, Allert N, et al. Bilateral highfrequency stimulation in the subthalamic nucleus for the treatment of Parkinson disease: correlation of therapeutic effect with anatomical electrode position. J Neurosurg 2002;96:269–279. Hilker R, Voges J, Weisenbach S, et al. Subthalamic nucleus stimulation restores glucose metabolism in associative and limbic cortices and in cerebellum: evidence from a FDG-PET study in advanced Parkinson’s disease. J Cereb Blood Flow Metab 2004;24:7–16. Treuer H, Klein D, Maarouf M, Lehrke R, Voges J, Sturm V. Accuracy and conformity of stereotactically guided interstitial brain tumour therapy using I-125 seeds. Radiother Oncol 2005;77:202–209. Herzog J, Volkmann J, Krack P, et al. Two-year follow-up of subthalamic deep brain stimulation in Parkinson’s disease. Mov Disord 2003;18:1332–1337. Strauss E, Sherman EMS, Spreen O. A Compendium of Neuropsychological Tests. Administration, Norms, and Commentary, 3rd edition ed. Oxford: University Press; 2006. Schaaf A, Kessler J, Grond M, Fink G. Memo Test. Ein verbaler Geda¨chtnistest nach der Methode des selektiven Erinnerns. Weinheim: Beltz-Test-Verlag; 1992. Helmstaedter C, Lendt M, Lux S. Verbaler Lern- und Merkfa¨higkeitstest (VLMT). Go¨ttingen: Hogrefe; 2001. Phelps ME, Huang SC, Hoffman EJ, Selin C, Sokoloff L, Kuhl DE. Tomographic measurement of local cerebral glucose metabolic rate in humans with (F-18)2-fluoro-2- deoxy-D-glucose: validation of method. Ann Neurol 1979;6:371–388. Wienhard K, Dahlbom M, Eriksson L, et al. The ECAT EXACT HR: performance of a new high resolution positron scanner. J Comput Assist Tomogr 1994;18:110–118. Pietrzyk U, Herholz K, Fink G, et al. An interactive technique for three-dimensional image registration: validation for PET, SPECT, MRI and CT brain studies. J Nucl Med 1994;35:2011–2018. Eidelberg D, Moeller JR, Dhawan V, et al. The metabolic topography of parkinsonism. J Cereb Blood Flow Metab 1994;14:783–801. Jacobson NS, Truax P. Clinical significance: a statistical approach to defining meaningful change in psychotherapy research. J Consult Clin Psychol 1991;59:12–19. Troster AI, Woods SP, Morgan EE. Assessing cognitive change in Parkinson’s disease: development of practice effect-corrected reliable change indices. Arch Clin Neuropsychol 2007;22:711–718. Gourovitch ML, Kirkby BS, Goldberg TE, et al. A comparison of rCBF patterns during letter and semantic fluency. Neuropsychology 2000;14:353–360. Costafreda SG, Fu CH, Lee L, Everitt B, Brammer MJ, David AS. A systematic review and quantitative appraisal of fMRI studies of verbal fluency: role of the left inferior frontal gyrus. Human Brain Mapp 2006;27: 799–810.

28.

29.

30. 31.

32.

Schroeder U, Kuehler A, Lange KW, et al. Subthalamic nucleus stimulation affects a frontotemporal network: a PET study. Ann Neurol 2003;54:445–450. Marsden CD, Obeso JA. The functions of the basal ganglia and the paradox of stereotaxic surgery in Parkinson’s disease. Brain 1994;117:877–897. Posner MI, Dehaene S. Attentional networks. Trends Neurosci 1994;17:75–79. Wager TD, Smith EE. Neuroimaging studies of working memory: a meta-analysis. Cogn Affect Behav Neurosci 2003;3:255–274. Mega MS, Cummings JL. Frontal-subcortical circuits and

33.

34.

35.

neuropsychiatric disorders. J Neuropsychiatry Clin Neurosci 1994;6:358–370. Botvinick M, Nystrom LE, Fissell K, Carter CS, Cohen JD. Conflict monitoring versus selection-for-action in anterior cingulate cortex. Nature 1999;402:179–181. Schroeder U, Kuehler A, Haslinger B, et al. Subthalamic nucleus stimulation affects striato- anterior cingulate cortex circuit in a response conflict task: a PET study. Brain 2002;125:1995–2004. Laplane D, Baulac M, Widlocher D, Dubois B. Pure psychic akinesia with bilateral lesions of basal ganglia. J Neurol Neurosurg Psychiatry 1984;47:377–385.

From the AAN History Library Collection Hammond’s A Treatise on Diseases of the Nervous System (1871) William Alexander Hammond (1828 –1900), as Surgeon General of the Union Army during the U.S. Civil War, reformed the medical service of the Union Army to ensure an efficient and effective military hospital system: he increased the size of the medical corps, improved field hospitalization by constructing numerous pavilion-style hospitals, improved hygienic practices, instituted an ambulance corps to quickly move injured soldiers to facilities where they could received needed medical care, and created the Army Medical Museum (later renamed the Armed Forces Institute of Pathology). He also authorized specialty hospitals for specific types of war injuries, including the 400-bed pavilion-style U.S. Army Hospital for Diseases of the Nervous System built on Turner’s Lane in Philadelphia in 1862. Following Hammond’s ignominious court martial on trumped up charges of impropriety in the purchase of supplies, he established a lucrative practice in New York and was instrumental in founding the American Neurological Association in 1875. Hammond’s textbook, A Treatise on Diseases of the Nervous System (1871), continues to be widely cited because it was the first American neurology textbook, and because it contains Hammond’s original description of athetosis. Athetosis, meaning “without fixed position,” was Hammond’s term for a condition “mainly characterized by an inability to retain the fingers and toes in any position in which they may be placed, and by their continual motion” (p. 654).1 These woodcuts show the hand postures of the two cases of athetosis Hammond described in his textbook.1 Douglas J. Lanska, MD, MS, MSPH, FAAN Chairman, AAN History Section 1. Hammond WA. A Treatise on Diseases of the Nervous System. New York: D. Appleton & Co., 1871, pp. 654 – 662. The American Academy of Neurology (AAN) Library Collection originated with a long-term donation of several thousand neurology-related books, many of them rare, by H. Richard Tyler, MD. The collection comprises more than 3,500 books, making it one of the world’s most significant research resources for the history of neurology and neurosciences. All the materials in the AAN collection are organized, processed, and easily retrievable for research. AAN members may use the collection by contacting Lilla Vekerdy, Librarian, at [email protected] or (314) 362-4235. If you have a passion for the history of neurology, consider applying for the H. Richard Tyler Award from the AAN which was established to encourage historical research using the AAN Library Collection at the Bernard Becker Medical Library at the Washington University School of Medicine in St. Louis. The award provides up to $1,200 for research expenses and is open to AAN members and non-members. For more information about the award, visit www.aan.com/libv or contact Jeff Sorenson at [email protected] or (651) 695-2728.

Neurology 72

January 6, 2009

49

Longitudinal prognostic value of serum “free” copper in patients with Alzheimer disease

R. Squitti, PhD F. Bressi, MD P. Pasqualetti, PhD C. Bonomini, PhD R. Ghidoni, PhD G. Binetti, MD E. Cassetta, MD F. Moffa, PhD M. Ventriglia, PhD F. Vernieri, MD P.M. Rossini, MD

Address correspondence and reprint requests to Dr. Rosanna Squitti, Department of Neuroscience, AFaROsp. Fatebenefratelli, 00186, Rome, Italy [email protected]

ABSTRACT

Background: Serum copper not bound to ceruloplasmin (“free”) appears slightly elevated in patients with Alzheimer disease (AD). We explored whether a deregulation of the free copper pool can predict AD clinical worsening.

Methods: We assessed levels of copper, iron, zinc, transferrin, ceruloplasmin, peroxides, total antioxidant capacity, free copper, and apolipoprotein E genotype in 81 patients with mild or moderate AD, mean age 74.4, SD ⫽ 7.4 years, clinically followed up after 1 year. The association among biologic variables under study and Mini-Mental State Examination (MMSE) (primary outcome), activities of daily living (ADL), and instrumental activities of daily living (IADL) (secondary outcomes) performed at study entry and after 1 year were analyzed by multiple regression. Results: Free copper predicted the annual change in MMSE, adjusted for the baseline MMSE by means of a linear regression model: it raised the explained variance from 2.4% (with only sex, age, and education) to 8.5% (p ⫽ 0.026). When the annual change in MMSE was divided into ⬍3 or ⱖ3 points, free copper was the only predictor of a more severe decline (predicted probability of MMSE worsening 23%: odds ratio ⫽ 1.23; 95% confidence interval ⫽ 1.03–1.47; p ⫽ 0.022). Hyperlipidemic patients with higher levels of free copper seemed more prone to worse cognitive impairment. Free copper at baseline correlated with the ADL and IADL clinical scales scores at 1 year. Conclusions: These results show an association between copper deregulation and unfavorable evolution of cognitive function in Alzheimer disease. Further research is needed to establish whether copper is an independent risk factor for cognitive decline. Neurology® 2009;72:50–55 GLOSSARY AD ⫽ Alzheimer disease; ADL ⫽ activities of daily living; BBB ⫽ blood– brain barrier; CB ⫽ ceruloplasmin; CI ⫽ confidence interval; IADL ⫽ instrumental activities of daily living; MMSE ⫽ Mini-Mental State Examination; OR ⫽ odds ratio.

Alzheimer disease (AD) is a form of dementia which progresses at different rates in different patients. Factors influencing or predicting the progression are not well understood. In a previous article, we reported that the ceruloplasmin-copper relationship, rather than absolute serum copper levels, represented the key to interpreting in vivo copper findings in AD.1 In particular, we discussed a deregulation of that relationship consisting of an increase in the serum copper portion that did not bind to ceruloplasmin, namely “free” copper,2 also correlating with the typical deficits and markers of the disease.1-3 Our observations were recently confirmed by two other groups, one in the Netherlands4 and one in the United States (Althaus J, personal communication). In particular, data from the latter study indicated that the free copper level in AD sera was nearly twice that in normal sera (AD 2.27 ⫾ 0.16 ␮mol/L; normal 1.56 ⫾ 0.29 ␮mol/L). Normally, the majority of human serum copper tightly binds to ceruloplasmin.5 The remaining copper—i.e., free copper—is distributed and exchanged

From the Department of Neuroscience (R.S., E.C., F.M., M.V., P.M.R.), AFaR-Osp. Fatebenefratelli, Isola Tiberina, Rome; Neurology (R.S., F.B., M.V., F.V., P.M.R.), University Campus Biomedico, Rome; Medical Statistics & Information Technology (P.P.), AFaR-Fatebenefratelli Association for Research, Isola Tiberina, Rome; Casa di Cura San Raffaele (P.P., P.M.R.), Cassino & IRCCS San Raffaele Pisana, Rome; and IRCCS Centro S. Giovanni di Dio-FBF (C.B., R.G., G.B.), Brescia, Italy. Supported by Grants of the Italian Health Department: “Tollerabilita` ed efficacia del tetratiomolibdato di ammonio (TM) nella malattia di Alzheimer” [RF 2006 conv.58] and by a grant from the AFaR Foundation–Osp. Fatebenefratelli, Rome, Italy. Disclosure: The authors report no disclosures. 50

Copyright © 2009 by AAN Enterprises, Inc.

among albumin, amino acids (e.g., histidine), and small molecular weight complexes (0.5– 5%; normal value ⬍1.6 ␮mol/L),5 which can easily cross the blood– brain barrier (BBB).6 Most studies of diagnostic markers focus on the early diagnosis of AD. Fewer studies have aimed at the identification of prognostic markers that influence the variation in rate of decline after patients have received the diagnosis of AD and little is known about the determinants of the variability. In this study, we explored the hypothesis that a deregulation of the free copper pool in serum could be a determinant of the variability of the progression of cognitive decline in a group of patients with mild or moderate AD. METHODS A total of 107 patients with probable AD according to National Institute of Neurological and Communicative Disorders and Stroke–Alzheimer’s Disease and Related Disorders Association,7 showing mild or moderate cognitive impairment (score ⱕ2 of the Clinical Dementia Rating)8 and a Mini-Mental State Examination (MMSE)9 score of 25 or less (range 16 –24), were recruited in two specialized dementia care centers: the Department of Neuroscience, Fatebenefratelli Hospital, Isola Tiberina, Rome, Italy, and the IRCCS, Fatebenefratelli Hospital of Brescia, Italy. Criteria for exclusion were conditions known to affect copper metabolism and biologic variables of oxidative stress on the basis of the past medical history and screening laboratory tests, reported in detail elsewere.1 We also excluded patients with a history of stroke, presence of focal neurologic signs, severe subcortical leukoencephalopathy, presence of hemodynamically significant neck and intracranial arteries stenosis or occlusion, or cardiopathy. When admitted to the study, patients underwent a structured clinical interview, a neurologic examination, brain MRI, an extensive neuropsychological assessment, biochemical measurements, and apolipoprotein E (APOE) genotyping. Blood was drawn on the same day of the clinical interview. Follow-up was performed 12 months after inclusion in the study. During this period, patients received the acetylcholinesterase inhibitor donepezil (5 mg daily for 3 months and then 10 mg daily) and compliance to the therapy was checked periodically by means of telephone contacts and visits performed at 3-month intervals. Progression of cognitive decline was evaluated by means of the MMSE (primary outcome) and activities of daily living (ADL) and instrumental activities of daily living (IADL) (secondary outcomes) performed at study entry and at the end of the follow-up period. The study was approved by the local ethical committee. All patients or caregivers gave written consent to be included in the study.

analyzed by immunoturbidimetry assay (Horiba ABX, Montpellier, France).12 For each serum copper and ceruloplasmin pair we computed the amount of copper bound to ceruloplasmin (CB) and the amount of copper not bound to ceruloplasmin (free copper) following standard procedures (appendix 1 of reference 5: “Calculation of ‘free copper’ concentration”)5; briefly: CB ⫽ ceruloplasmin (mg/dL) ⫻ 10 ⫻ n; n ⫽ 0.0472 (␮mol/mg); free copper ⫽ absolute serum copper ⫺ CB.5 This calculation expresses free copper in ␮mol/L and is based on the notion that ceruloplasmin contains 0.3% copper.5 Thus, for a patient with a serum absolute (or total) copper concentration of 17.3 ␮mol/L and a serum ceruloplasmin concentration of 33 mg/dL, the bound copper concentration ⫽ 33 ⫻ 10 ⫻ 0.0472 ⫽ 15.6 ␮mol/L, and the free copper concentration ⫽ 17.3–15.6 ⫽ 1.7 ␮mol/L. Moreover, we have recently set up an automated procedure to measure ceruloplasmin oxidase activity which utilizes o-diansidine dihydrochloride as a substrate, according to previous methods.13,14 In fact, it is well known that values of ceruloplasmin obtained immunologically, as we showed them in this study, result in higher values than those obtained enzymatically, i.e., monitoring the protein’s oxidase activity.5,13,14 This is because the apo-form of ceruloplasmin is biologically inactive.5 In normal controls, the two detection methods showed a significant correlation (data not shown), as also reported by other authors.5,13,14 However, quantification of ceruloplasmin by the enzymatic method based on standard ceruloplasmin solutions has not been considered by the majority of previous authors,13 because of its cost, the variable purity of commercially available ceruloplasmin, and the general recommendation to report serum enzymes in International Units.13 We have tried to quantify the amount of ceruloplasmin starting from the protein’s oxidase activity with a commercial standard (Human Serum Ceruloplasmin, Sigma-Aldrich), but the spectroscopic inspection of the latter revealed a decay in the protein peak of absorbance in dayto-day assays (data not shown), decreasing our confidence in using the enzymatic detection to quantify the protein amount, necessary to estimate the free copper value. Measurements of the other biologic variables of oxidative stress are described in detail elsewhere.15 Briefly, hydro-peroxide content was assessed by d-ROMs test (Diacron, Italy) and expressed in arbitrary units (U.CARR), 1 U.CARR corresponding to 0.08 mg/100 mL of hydrogen peroxide. Normal range was between 230 and 310 U.CARR.16 Total radical trapping antioxidant capacity, or TRAP, was assayed by the TAS kit (Randox Laboratories, Crumlin, UK), based on published methods.17 The serum reference range is 1.30 – 1.77 mmol/L.17 Transferrin level was analyzed by immunoturbidimetry assay,18 and iron using Ferene.19 All these reagents were ABX Pentra from Horiba ABX (Montpellier, France). Zinc levels were measured using the specific complexant 5-Br-PAPS [(2-5bromo-2-pyridylazo)-5-(N-propyl-N-sulfo-propylamino) phenol]20 according to manufacturer’s instructions (Zinc, Sentinel Diagnostic, Milan, Italy). All biochemical measures were automated on a Cobas Mira Plus (Horiba abx, Montpellier, France) and performed in duplicate. APOE genotyping was performed according to standard methods.21

Biochemical and molecular investigations. Patients’ fasting blood samples were collected in the morning and serum was rapidly stored at ⫺80°C. Serum copper concentration was estimated following the method of Abe et al. (Randox Laboratories, Crumlin, UK)10 and by an A Analyst 300 Perkin Elmer atomic absorption spectrophotometer equipped with a graphite furnace with platform HGA 800 (Foster City, CA).11 Ceruloplasmin was

MRI evaluation. Brain MRI was performed using a 1.5 Tesla superconductor magnet. The imaging protocol consisted of axial T2 W double spin echo sequences and T1 W spin echo images in axial, coronal, and sagittal planes, with 5 mm slice thickness and intersection gap ⫽ 0.5 mm. An extensive MRI evaluation was performed (data not shown). Briefly, the spin echo technique and T1 W, T2 W, and fluid-attenuated inversion-recovery sequences detected posNeurology 72

January 6, 2009

51

Table 1

Baseline characteristics, Mini-Mental State Examination (MMSE) scores, and circulating copper metabolism evaluation (baseline and at 1 year) of the 81 patients with Alzheimer disease

Characteristics

Values

Age, y, mean (SD)

74.4 (7.4)

Sex, % men

17

MMSE score, mean (SD)

20.5 (3.5)

Risk factors, % Hypertension

36

Hyperlipidemia

13

Smoking

33

Cardiopathy

9

MRI findings, % Subcortical infarcts (grade I)

44.5

Medial temporal lobe atrophy

71

Drugs, % Antihyperlipidemia agents

23

Statins

24

Oral hypoglycemic agents

11

Antiplatelet aggregation agents

43

Antihypertensive drugs

39

␤-Blockers

11

Calcium antagonists

17

Diuretics

14

APOE ␧4 frequency (%)

24.5

Biological variables of copper in serum, mean (SD) Basal copper (␮mol/L)

15.6 (3.5)

Basal ceruloplasmin (mg/dL)

27.7 (6.3)

Basal free copper (␮mol/L)

2.5 (2.9)

Cognitive evaluation, mean (SD) Basal MMSE scores

20.5 (3.5)

One-year MMSE scores

17.3 (4.7)

sible white matter lesions. These were graded according to published protocols.22 Only patients without vascular lesions (grade 0) or with small subcortical focal lesions defined as high signal intensity areas on T2-weighted images, but isointense with normal brain parenchyma on T1-weighted images and classified as grade I (44.5%; table 1), were included. Volumetric analysis of the hippocampus was visually performed by scoring every patient according to the width of the choroid fissure and the temporal horn, following the criteria of a rating scale of temporal lobe atrophy previously reported (five point rating scale of medial temporal lobe atrophy [MTA]).1,22 MRI revealed that atrophy of the medial temporal lobes with a reduction in hippocampal volume (score 2– 4) was prominent (71%; table 1) in the patients.

Statistical analyses. Formal sample size calculation was not performed because this was an exploratory study of possible correlation between metal and oxidative biologic variables and impairment and severity of progressive cognitive decline. However, 52

Neurology 72

January 6, 2009

we considered as relevant a bivariate correlation of 0.40 (corresponding to 16% of accounted variance) and calculated that a sample size of 50 patients would result in a power of 86% (with bilateral ␣ at 0.05). The aim of the study was to see whether and how severe the progression of cognitive decline was in relation to metal and oxidative biologic variables alterations. Attaining this goal was best served by a regression model. A multiple regression analysis was applied to test the potential confounding role of demographic characteristics (sex, age, and education) and vascular risk factors (hypertension, smoking habits, and hyperlipidemia), then the linearity of the relationship between metal and oxidative biologic variables alterations and severity of progression of cognitive impairment was tested using a polynomial regression and the best-fitting model (maximum R 2 and significant R 2 change vs the previous model) was chosen. To provide additional information potentially useful for clinicians, outcome cognitive variables were dichotomized in two groups: above or equal to 3 points MMSE decrease (severe cognitive decline) and below 3 (milder cognitive decline). Impairment was evaluated using a logistic regression model. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated.

Eighty-one of the 107 subjects completed the follow-up after 1 year. The main baseline demographic and medical characteristics of these patients are reported in table 1, along with evaluations of free copper and MMSE at baseline and at the 1 year follow-up. Patients were affected mainly by hypertension (36%), cardiopathy (9%), hyperlipidemia (13%), diabetes (11%), and smoking (33%). The most frequent drugs taken by patients were antiplatelet aggregation agents (43%), statins (24%), and antihypertensive drugs (39%), mostly represented by calcium antagonist (17%). During the study, all patients received acetylcholinesterase inhibitors. Allele APOE ␧4 frequency was 24.5%. The APOE ␧4 allele was more prevalent in patients born in northern Italy (35%) than in central/southern Italy (17%; p ⫽ 0.013). Patients at baseline had mild to moderate dementia (MMSE: mean ⫽ 20.5, SD ⫽ 3.5). Sixty-five percent of patients had a higher than normal free copper (⬍1.6 ␮mol/L).5 Patients who were carriers of the APOE ␧4 allele had higher levels of free copper than noncarriers (data not shown).11 After 1 year, MMSE decreased by 3.2 points (SD ⫽ 3.9; p ⬍ 0.001; table 1). RESULTS Patients.

Prediction of cognitive decline. Baseline cognitive sta-

tus could be the first predictor of cognitive deterioration. In consideration of this, the annual change in MMSE was adjusted for the baseline MMSE by means of a linear regression model, even though only 4% of change variance was accounted for by baseline measurement. We then analyzed the correlations between cognitive decline at 1 year and the biologic variables under study. The analysis revealed that the higher the annual change in MMSE, the higher both

Table 2

Correlations between annual change in Mini-Mental State Examination and biological variables of metals and oxidative stress in serum

Serum biological variable of metals and oxidative stress at baseline

Annual change in MMSE

Copper Pearson correlation

0.219*

Significance (two-tailed)

0.050

No.

81

Zinc Pearson correlation Significance (two-tailed) No.

⫺0.218 0.103 57

Iron Pearson correlation

0.058

Significance (two-tailed)

0.640

No.

68

Transferrin Pearson correlation Significance (two-tailed) No.

⫺0.111 0.347 74

Ceruloplasmin Pearson correlation Significance (two-tailed) No.

⫺0.001 0.990 81

Free copper Pearson correlation

0.256*

Significance (two-tailed)

0.021

No.

81

Peroxides Pearson correlation Significance (two-tailed) No.

⫺0.051 0.649 81

Total radical trapping antioxidant capacity Pearson correlation Significance (two-tailed) No.

0.169 0.137 79

*Correlation is significant at the 0.05 level (two-tailed).

the absolute copper and free copper (table 2), while the MMSE at baseline did not correlate with copper biologic variables (all p values ⬎0.17). The relationship between copper variables and cognitive decline was studied further: when the annual change in MMSE was entered as a dependent variable in a linear regression model, free copper proved to be a significant covariate, since it raised the explained variance from 2.4% (with only sex, age, and education) to 8.5%. In particular, the slope of the regression was b ⫽ 0.316 (SE ⫽ 0.140; p ⫽ 0.026)

indicating that about 3 ␮mol/L units of free serum copper explained a one-point loss on the annual change in the MMSE. To better quantify our model the analysis of influential statistics was applied (based on changes in regression coefficients and on leverage measures): this analysis indicated that the exclusion of outlier cases with a potentially detrimental effect on the regression model did not change the relationship between free copper and MMSE changes (data not shown). We also observed an effect of hyperlipidemia on cognitive decline. Hyperlipidemia was associated with a 2.6 point loss on the annual change in MMSE. Hyperlipidemia accounted for 4.8% of residual variance (p ⫽ 0.058). Hyperlipidemic patients with higher levels of free copper seemed more prone to higher cognitive impairment. When the annual change in MMSE scores were divided into ⬍3 or ⱖ3 points, the multiple logistic regression indicated that free copper was the only predictor of more severe decline; for each additional ␮mol/L unit of free copper, the odds of MMSE worsening increased by about 23% (OR ⫽ 1.23; 95% CI ⫽ 1.03–1.47; p ⫽ 0.022). Those patients from the current study panel who had a value of free copper higher than 2.1 ␮mol/L had an increased probability of worsening than those patients who had their free copper values below such levels (figure). Diabetes had no effect in explaining cognitive decline even after adjusting for free copper values (p ⬎ 0.2). Drug treatment effects were taken into account in the analysis. Concentrations of free serum copper [t(79) ⫽ 3.746; p ⬍ 0.001] and cognitive decline [t(79) ⫽ 3.716; p ⫽ 0.005] were lower in those patients who were administered with calcium antagonists. When this effect was included in the multiple regression analysis, free copper could not enter the model for prognosis evaluation. Free copper correlated with the ADL and IADL clinical scales which evaluate the disabilities in daily living of the patients. At baseline, higher levels of free copper corresponded to lower ADL scores at the 1-year evaluation (rho ⫽ ⫺0.299, p ⫽ 0.018). The higher were free copper levels, the lower were IADL scores either at baseline (rho ⫽ ⫺0.0349, p ⫽ 0.001) or at 1 year (rho ⫽ ⫺0.359, p ⫽ 0.004). The most important result of this study suggests that a deregulation of free copper could determine the variability of the progression of cognitive decline in AD. However, the implication of free copper in this disease was based on correlative studies. Therefore, the present study does not allow a conclusive interpretation about a causal pathophysio-

DISCUSSION

Neurology 72

January 6, 2009

53

Figure

Model to predict the probability of Mini-Mental State Examination (MMSE) worsening in patients affected by Alzheimer disease (AD) according to “free” serum copper levels

Circles represent the value of free serum copper of the patients. The line represents the model of the predicted probability of MMSE worsening. Free copper levels in individual patients with AD are expressed in z-score, i.e., in terms of standard deviations from their mean value. Those patients from the current study panel who had a z-score higher than ⫺0.138, corresponding to a free copper value of 2.1 ␮mol/L, had an increased probability to worsen than those patients who had their free copper values below such levels.

logic effect of serum copper abnormalities on cognitive decline. Our current findings show that higher levels of free copper could explain a decline in MMSE scores. In spite of the relatively low percentage of explained variance of free copper, the most interesting aspect of our study is the possibility of obtaining useful information for identification of patients with AD at higher risk for a rapid and pronounced evolution of cognitive impairment by means of a simple blood test. The majority of studies report that there is heterogeneity in the progression of AD. The severity of cognitive impairment at baseline,23 as well as hippocampal atrophy,24 are suggested to be important predictors of progression. With regard to those patients with a free copper dysfunction, estimated to be 65% of our patients, a free copper value higher than normal seems to represent a determinant of progression variability. In particular, a value of free copper higher than 2.1 ␮mol/L increased the probability of loss of 3 points in a year on the MMSE. These results are consistent with the hypothesis that even a small increase of the serum low molecular weight copper, i.e., free copper, can be of significance, particularly over a long period of time. In fact, free copper is potentially toxic as it can promote oxidative stress,25 54

Neurology 72

January 6, 2009

because this low molecular weight copper can easily cross the BBB and supply the brain with a continuous flux of noxious redox copper. This interpretation is supported by results of an experiment with mice to test the effects of radiocopper [67Cu(II)] brain uptake during a single passage through the telencephalon-diencephalon microcirculation which demonstrates that net brain copper uptake parallels the increase of the free copper level in the injectate, starting from a concentration of Cu (II) of 3.2 ng/mL, corresponding to 0.05 ␮mol/L.26 In the present study, changes in ADL and IADL—which predict future functional decline, institutionalization, and death—were evaluated in relation to copper status. Patients with higher levels of free copper at baseline seemed to have a faster and more pronounced evolution of disabilities, in parallel with the progression of cognitive decline. Our data indicate that hyperlipidemia was the only risk factor associated with MMSE worsening. Even though it is relevant in a small number of patients, we demonstrated an interaction between free copper and hyperlipidemia on cognitive decline in agreement with other authors who used different study design approaches.27,28 The impact of serum copper on cognitive decline in this study was not affected by age, sex, or education. We have tried to control confounders by selecting patients with no evidence of additional pathologic conditions, and by taking into account cardiovascular risk and drug treatment. In this patient sample we noted that subjects who were taking a calcium antagonist therapy had lower levels of circulating free copper. A possible explanation is a diminished rate of copper absorption at the intestinal level. This study has a number of limitations, which include the shortage duration of the clinical followup, the need for patient selection that possibly resulted in sampling bias, and the refusal to perform follow-up evaluation by some patients that reduced the number of subjects initially involved in the study. Another interesting result of this study concerns the possibility that a therapeutic intervention aimed at metal levels could have favorable practical implications for the management of AD.29 Therapeutic strategies available for copper’s diseases, i.e., Wilson disease, at least in a subgroup of patients with AD with impaired copper metabolism, deserve further study. ACKNOWLEDGMENT The authors thank Dr. Samantha Galluzzi for providing MRI data and Dr. Carlo Salustri for manuscript revision.

Received May 9, 2008. Accepted in final form September 24, 2008. REFERENCES 1. Squitti R, Pasqualetti P, Dal Forno G, et al. Excess of serum copper not related to ceruloplasmin in Alzheimer disease. Neurology 2005;64:1040–1046. 2. Squitti R, Barbati G, Rossi L, et al. Excess of nonceruloplasmin serum copper in AD correlates with MMSE, CSF ␤-amyloid, and h-tau. Neurology 2006;67:76–82. 3. Capo CR, Arciello M, Squitti R, et al. Features of ceruloplasmin in the cerebrospinal fluid of Alzheimer’s disease patients. Biometals 2008;21:367–372. 4. Hoogenraad TU. Measuring hypercupremia in blood of patients with Alzheimer’s disease is logical, but the utility of measuring free-copper has to be proven. In: Frijns CJM, Kappelle LJ, Klijn CJM, Wokke JHJ. Neurologie. Utrechts Tijdschrift voor; 2007:111–112. 5. Walshe JM. Wilson’s disease: the importance of measuring serum caeruloplasmin non-immunologically. Ann Clin Biochem 2003;40:115–121. 6. Hoogenraad TU. Monography: Wilson’s disease. In: Major Problems in Neurology. Vol 30. London: W.B. Saunders; 1996. 7. McKhann G, Drachman D, Folstein M, et al. Clinical diagnosis of Alzheimer’s disease: report of the NINCDSADRDA Work Group under the auspices of Department of Health and Human Services Task Force on Alzheimer’s Disease. Neurology 1984;34:939–944. 8. Morris JC. The Clinical Dementia Rating (CDR): current version and scoring rules. Neurology 1993;43:2412–2414. 9. Folstein MF, Folstein SE, McHugh PR. “Mini-mental state”: a practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res 1975;12:189– 198. 10. Abe A, Yamashita S, Noma A. Sensitive, direct colorimetric assay for copper in serum. Clin Chem 1989;35:552– 554. 11. Squitti R, Lupoi D, Pasqualetti P, et al. Elevation of serum copper levels in Alzheimer’s disease. Neurology 2002;59: 1153–1161. 12. Wolf PL. Ceruloplasmin: methods and clinical use. Crit Rev Clin Lab Sci 1982;17:229–245. 13. Lehmann HP, Schosinsky KH, Beeler MF. Standardization of serum ceruloplasmin concentrations in international enzyme units with o-dianisidine dihydrochloride as substrate. Clin Chem 1974;20:1564–1567. 14. Schosinsky KH, Lehmann HP, Beeler MF. Measurement of ceruloplasmin from its oxidase activity in serum by use of o-dianisidine dihydrochloride. Clin Chem 1974;20: 1556–1563.

15.

16.

17.

18.

19. 20.

21.

22.

23.

24.

25.

26.

27.

28.

29.

Squitti R, Rossini PM, Cassetta E, et al. d-penicillamine reduces serum oxidative stress in Alzheimer’s disease patients. Eur J Clin Invest 2002;32:51–59. Alberti A, Bolognini L, Macciantelli D, Carratelli M. The radical cation of N,N-Diethyl-para-phenylendiamine: a possible indicator of oxidative stress in biological samples. Res Chem Intermed 2000;26:253–267. Rice-Evans C, Miller NJ. Total antioxidant status in plasma and body fluids. Methods Enzymol 1994;234: 279–293. Skikne BS, Flowers CH, Cook JD. Serum transferrin receptor: a quantitative measure of tissue iron deficiency. Blood 1990;75:1870–1876. Higgins T. Novel chromogen for serum iron determinations. Clin Chem 1981;27:1619–1620. Maffulli V, De Luca U. A new direct colorimetric method for the determination of zinc in biochemical fluids without deproteinization of the sample. European Clinical Laboratory, Biochemicals/Application Note, 1992. Hixson JE, Vernier DT. Restriction isotyping of human apolipoprotein E by gene amplification and cleavage with HhaI. J Lipid Res 1990;31:545–548. Scheltens P, Launer LJ, Barkhof F, et al. Visual assessment of medial temporal lobe atrophy on magnetic resonance reliability. J Neurol 1995;242:557–560. Carcaillon L, Pe´re`s K, Pe´re´ JJ, et al. Fast cognitive decline at the time of dementia diagnosis: a major prognostic factor for survival in the community. Dement Geriatr Cogn Disord 2007;23:439–445. Sluimer JD, Vrenken H, Blankenstein MA, et al. Wholebrain atrophy rate in Alzheimer disease: identifying fast progressors. Neurology 2008;70:1836–1841. Brewer GJ. Iron and copper toxicity in diseases of aging, particularly atherosclerosis and Alzheimer’s disease. Exp Biol Med (Maywood) 2007;232:323–335. Chutkow JG. Evidence for uptake of nonceruloplasminic copper in the brain: effect of ionic copper and amino acids. Proc Soc Exp Biol Med 1978;158:113–116. Sparks DL, Schreurs BG. Trace amounts of copper in water induce beta-amyloid plaques and learning deficits in a rabbit model of Alzheimer’s disease. Proc Natl Acad Sci USA 2003;100:11065–11069. Morris MC, Evans DA, Tangney CC, et al. Dietary copper and high saturated and trans fat intakes associated with cognitive decline. Arch Neurol 2006;63:1085–1088. Ritchie CW, Bush AI, Mackinnon A, et al. Metal-protein attenuation with iodochlorhydroxyquin (clioquinol) targeting Abeta amyloid deposition and toxicity in Alzheimer disease: a pilot phase 2 clinical trial. Arch Neurol 2003;60: 1685–1691.

Neurology 72

January 6, 2009

55

Microglial activation and amyloid deposition in mild cognitive impairment A PET study

A. Okello, MRCP P. Edison, MRCP H.A. Archer, MRCP F.E. Turkheimer, PhD J. Kennedy, MRCP R. Bullock, MA, MRCPsych Z. Walker, MD A. Kennedy, MD N. Fox, PhD M. Rossor, MD, DSc D.J. Brooks, MD, DSc

Address correspondence and reprint requests to Dr. Aren Okello, Cyclotron Building, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK [email protected]

ABSTRACT

Background: Activated microglia may play a role in the pathogenesis of Alzheimer disease (AD) as they cluster around beta-amyloid (A␤) plaques. They are, therefore, a potential therapeutic target in both AD and its prodrome amnestic mild cognitive impairment (MCI). C-(R)-PK11195 and 11C-PIB PET the distribution of microglial activation and amyloid deposition in patients with amnestic MCI.

Objective: To characterize in vivo with

11

Methods: Fourteen subjects with MCI had 11C-(R)-PK11195 and 11C-PIB PET with psychometric tests. Results: Seven out of 14 (50%) patients with MCI had increased cortical 11C-PIB retention (p ⬍ 0.001) while 5 out of 13 (38%) subjects with MCI showed increased 11C-(R)-PK11195 uptake. The MCI subgroup with increased 11C-PIB retention also showed increased cortical 11C-(R)PK11195 binding (p ⬍ 0.036) though this increase only remained significant in frontal cortex after a correction for multiple comparisons. There was no correlation between regional levels of 11 C-(R)-PK11195 and 11C-PIB binding in individual patients with MCI: only three of the five MCI cases with increased 11C-(R)-PK11195 binding had increased levels of 11C-PIB retention.

Conclusions: Our findings indicate that, while amyloid deposition and microglial activation can be detected in vivo in around 50% of patients with mild cognitive impairment (MCI), these pathologies can occur independently. The detection of microglial activation in patients with MCI suggests that anti-inflammatory therapies may be relevant to the prevention of AD. Neurology® 2009;72:56–62 GLOSSARY A␤ ⫽ beta-amyloid; AD ⫽ Alzheimer disease; BP ⫽ binding potential; MCI ⫽ mild cognitive impairment; MMSE ⫽ Mini-Mental State Examination; PBBS ⫽ peripheral benzodiazepine binding site; ROI ⫽ region of interest; SD ⫽ standard deviation; SRTM ⫽ simplified reference tissue model.

There has been increasing interest in the early identification of subjects who have memory impairment beyond that expected with normal aging, but who do not fulfill criteria for dementia. These cases have been labeled as having amnestic mild cognitive impairment (MCI).1 The positron emitting radiotracer 11C-PIB (Pittsburgh compound B) is a neutral derivative of thioflavin-T with nanomolar affinity for fibrillar amyloid in the AD brain.2 Using 11C-PIB (N-methyl-[11C] 2-(4=-methylaminophenyl)-6-hydroxybenzothiazole) with PET it has been possible to localize and quantify A␤ plaque load in vivo. Several PET studies have reported increased cortical 11C-PIB uptake in 90% of patients with probable AD3-8 while around 50% of patients with amnestic MCI also have significantly raised uptake.5,8-10 Although the formation of A␤ and neurofibrillary tangles are key features in AD pathogenesis, activated microglia are thought to be important and have been shown to cluster around sites of A␤ in human postmortem brain slices and in transgenic mouse models of AD.11,12 The PET radiotracer Supplemental data at www.neurology.org From the Division of Neuroscience and Mental Health (A.O., P.E., F.E.T., A.K., D.J.B.), Faculty of Medicine, Imperial College London; Dementia Research Centre, Department of Neurodegenerative Disease, Institute of Neurology (H.A.A., J.K., N.F., M.R.), and Department of Mental Health Sciences (Z.W.), University College London; Kingshill Research Centre (R.B.), Victoria Hospital, Swindon; and Hammersmith Imanet (D.J.B.), GE Healthcare, London, UK. Disclosure: This work was conducted in collaboration with Imanet, GE Healthcare. The Dementia Research Centre is an Alzheimer’s Research Trust Coordinating Centre. UCLH/UCL received a proportion of funding from the Department of Health’s NIHR Biomedical Research Centres funding scheme. A. Okello is an Alzheimer’s Research Trust research associate; P. Edison is a Medical Research Council clinical research fellow; H. Archer received funding from the Alzheimer’s Research Trust; J. Kennedy is supported by funding from the Alzheimer’s Research Trust; Z. Walker has received consultancy fees from GE Healthcare; N. Fox is a Medical Research Council senior clinical fellow; David Brooks is Head of Neurology, Medical Diagnostics, GE Healthcare. 56

Copyright © 2009 by AAN Enterprises, Inc.

Table 1

Demographic details of patients with MCI

Total no.

MCI: total

MCI: AD-range PIB

MCI: norm-range PIB

11

C-PIB controls

11

AD

14

7

7

22

14

10

C-(R)-PK11195 controls

Mean age, y ⴞ SD

66.6 ⫾ 9.6

69.1 ⫾ 6.4

64 ⫾ 11.9

64.9 ⫾ 6.4

63.9 ⫾ 5.3

60.2 ⫾ 9.3

Gender: women/total

5/14

3/7

2/7

10/22

6/14

4/10

—

—

29.8 ⫾ 0.43

29.9 ⫾ 0.32

Mean duration of symptoms, y ⴞ SD Mean MMSE ⴞ SD

4.1 ⫾ 2.1

3.4 ⫾ 0.8

4.7 ⫾ 2.9

5.5 ⫾ 3.8

27.7 ⫾ 1.5

28.1 ⫾ 1.4

27 ⫾ 2.2

21.5 ⫾ 3.6

MCI ⫽ mild cognitive impairment; AD ⫽ Alzheimer disease; norm-range ⫽ normal-range; MMSE ⫽ Mini-Mental State Examination; SD ⫽ standard deviation. 11

C-(R)-PK11195 (1-[2-chlorophenyl]-Nmethyl-N-[1-methyl-propyl]-3-isoquinoline carboxamide) is a ligand that is specific for the peripheral benzodiazepine binding site (PBBS), a receptor abnormally expressed by the mitochondria of activated microglia.13 Increased binding of 11C-(R)-PK11195 has been reported in AD,14,15 and other neurodegenerative disorders including frontotemporal dementia16 and Parkinson disease,17 indicating that microglia activation is a nonselective response to neuronal damage. The precise role of microglial activation and its relationship to A␤ remains controversial. Microglia phagocytose dead cells, remodel synapses, and remove A␤ fibrils18,19 but also have damaging effects, releasing cytokines and nitric oxide.20 Less is known about their relevance to MCI. Using the PET radiotracers 11C-PIB and 11 C-(R)-PK11195 we sought to characterize and compare in vivo the patterns of amyloid deposition and microglial activation in a group of subjects with MCI. METHODS Subjects with MCI. Fourteen subjects (mean age 66.6 years; SD 9.6) fulfilling Petersen’s criteria for amnestic MCI1 participated in the study (table 1). All subjects underwent both 11C-PIB and 11C-(R)-PK11195 PET on separate occasions (mean interval between scans 6.4 ⫾ 5.4 weeks). Subjects were recruited from the Hammersmith Hospitals NHS Trust (UK), the National Hospital for Neurology and Neurosurgery (UK), St. Margaret’s Hospital (UK), and Victoria Hospital (UK). All patients had a comprehensive assessment including neurologic examination, neuropsychological testing, and MRI. Patients with significant white matter disease in the view of an experienced radiologist were excluded from the study. Ethical approval was granted by the Hammersmith and Queen Charlotte’s Hospitals ethics committee. All patients gave informed written consent prior to their participation.

Subjects with AD and healthy controls. PET data from 22 subjects (mean age 64.9 years; SD 6.4) meeting the National Institute of Neurological and Communicative Disorders and Stroke/Alzheimer’s Disease and Related Disorders Association21

criteria for the diagnosis of probable AD were used for comparison with our MCI group. All 22 AD subjects had 11C-PIB (PIB) PET and, of these, 15 (mean age 63.7 years; SD 6.0) additionally had 11C-(R)-PK11195 (PK) PET (mean scan interval 3.1 ⫾ 2.8 weeks). PIB PET data from 14 controls (mean age 63.9 years; SD 5.3) and PK PET data from 10 controls (mean age 60.2 years; SD 9.3) were also used for comparison with the MCI group. Eighteen of the 22 patients with AD and 11 of the 14 controls have had their PIB PET data previously reported.7 PK PET data for 11 of the 15 patients with AD and 8 of the 10 controls have now been accepted for publication. We have included these reference data so that our novel MCI PET data may be interpreted in context.

MRI scanning. All subjects underwent volumetric T1weighted MRI for the purpose of structure- function coregistration with PET and T2-weighted MRI to exclude structural lesions. 11 C-PIB and 11C(R)-PK11195 was obtained from the Administration of Radioactive Substances Advisory Committee of the United Kingdom. 11 C-PIB and 11C-(R)-PK11195 were manufactured and supplied by GE Healthcare, Hammersmith Hospital, UK.

PET scanning. Permission to administer

11

C-PIB PET. All subjects were scanned using a Siemens ECAT EXACT HR⫹ camera in three-dimensional acquisition mode using a scanning protocol described previously.7 Subjects received 366 ⫾ 26.8 MBq 11C-PIB, injected IV. Image analysis: 11C-PIB PET. Target region: cerebellar cortex ratio images of PIB retention were generated as follows: 10 –90 minute (total) and 60 –90 minute (late) summation images were created in Matlab. Each MRI was segmented into gray, white matter, and CSF images using Statistical Parametric Mapping software (SPM2; Wellcome Department of Imaging Neuroscience, University College London, UK). The probabilistic gray matter image was binarized by thresholding at 50% probability. Both summation PET images were then coregistered to individual subjects’ MRIs which were used as a template to spatially normalize those PET images and binarized MRI probability gray matter image into Montreal Neurological Institute space. Using Analyze software (Mayo Clinic, MN), we convolved the binarized gray matter image with an in-house probabilistic brain atlas.22 This creates an individualized anatomic atlas for each subject in standard space which is used as a template to sample a priori designated regions of interest (ROIs). At this stage, 11C-PIB activity in the reference region (cerebellar cortex) is sampled. Finally, the late summation images were normalized to the mean cerebellar cortical uptake value over this 60 –90Neurology 72

January 6, 2009

57

Table 2

Ant cingulate

analysis of PIB images, and PK BPs quantified in the same brain regions described earlier.

Mean PIB retention values in AD, MCI, and healthy controls

AD (n ⴝ 22)

MCI (n ⴝ 14)

MCI: AD-range (n ⴝ 7)

2.23 ⫾ 0.42

1.64 ⫾ 0.56

2.14 ⫾ 0.33*

MCI: normal-range (n ⴝ 7)

HC (n ⴝ 14)

1.15 ⫾ 0.06

1.17 ⫾ 0.12

Statistical analysis. Statistical tests were performed using

Post cingulate

2.22 ⫾ 0.40

1.67 ⫾ 0.59

2.19 ⫾ 0.34*

1.16 ⫾ 0.09

1.20 ⫾ 0.07

Frontal

2.06 ⫾ 0.37

1.54 ⫾ 0.49

1.95 ⫾ 0.34*

1.12 ⫾ 0.02

1.10 ⫾ 0.07

Temporal

1.86 ⫾ 0.34

1.45 ⫾ 0.43

1.78 ⫾ 0.39*

1.11 ⫾ 0.04

1.12 ⫾ 0.03

Parietal

2.02 ⫾ 0.37

1.51 ⫾ 0.50

1.92 ⫾ 0.41*

1.11 ⫾ 0.04

1.11 ⫾ 0.05

Whole brain

1.96 ⫾ 0.34

1.49 ⫾ 0.46

1.86 ⫾ 0.37*

1.13 ⫾ 0.03

1.12 ⫾ 0.05

Values ⫽ mean ⫾ SD. *p ⬍ 0.001 for MCI: AD-range vs controls. AD ⫽ Alzheimer disease; MCI ⫽ mild cognitive impairment; HC ⫽ healthy control; Ant cingulate ⫽ anterior cingulate; Post cingulate ⫽ posterior cingulate.

minute period, generating the late ratio image. We used a late scan reference region approach because it provides a robust measure of total: nonspecific PIB relative volumes of distribution in target brain regions without the need for arterial sampling. The cerebellum was chosen as the reference region as it is relatively free of fibrillar plaques, reflected by its lack of staining with Congo red and thioflavins.23

ROI analysis. We quantified PIB retention in the anterior cingulate, posterior cingulate, frontal, temporal, and parietal cortex. Additionally, whole brain retention was quantified, although not considered as a region when performing statistical analysis. 11

C-(R)-PK11195 PET. All subjects were scanned using an ECAT EXACT HR ⫹⫹ (CTI/Siemens, Knoxville, TN) PET Tomograph (three-dimensional mode) which has a total axial field of view of 23.4 cm. Subjects received 299 ⫾ 16 MBq 11C(R)-PK11195 injected IV and scanning was performed in list mode and the dynamic images rebinned over 60 minutes as 18 time frames. 11 C-(R)-PK11195 PET. Parametric images of PK binding potential (BP) were generated by a simplified reference tissue model (SRTM), using RPM software written in Matlab.24 Unlike fibrillar amyloid plaques, activated microglia are distributed throughout all brain regions in AD, including the cerebellum,25 potentially making the selection of a suitable reference region for nonspecific signal difficult. We, therefore, used a supervised clustering technique to derive a nonspecific uptake tissue reference input function in all groups studied. This technique produces BP estimates that are reproducible and comparable to those derived from plasma input.26,27 In summary, the method uses six predefined kinetic classes to extract as a reference region a cluster of gray matter voxels in each individual that exhibits the kinetic behavior closest to that of gray matter in a population of healthy controls. The supervised clustering algorithm avoids regions with specific binding such as association cortex in AD and large vessels, and the resulting cluster of voxels is clear of unwanted spurious signals arising from areas of the brain known to have a rich density of PBBS receptors such as the meninges. The resulting parametric PK BP images and 60-minute summation images were then coregistered to each subject’s MRI. The 60-minute summation image contains blood flow dependent signal, providing good anatomic detail, enabling accurate coregistration. Spatial normalization and creation of gray matter object maps were performed by the same methods described for

Image analysis:

58

Neurology 72

January 6, 2009

SPSS for Windows 14.0 statistical software. Repeated measures analysis of variance was applied to test for global differences in PIB and PK binding between MCI groups and controls, using the Greenhouse Geisser factor to correct for variance heterogeneity across regions. Univariate analysis of variance was used to detect significant differences in regional PIB and PK binding between groups, using age as a covariate and the p plot method to control for multiple comparisons.28 Because of the heterogeneity of PK binding within the two MCI subgroups (those with increased AD-range and normal control-range PIB binding), PK BPs in subjects with MCI are also described on an individual basis. We considered regional PK binding to be raised if ⱖ2 SD greater than the control mean BP for that region. Pearson’s rank correlation coefficient was used to interrogate the correlation between PIB and PK binding in subjects with MCI. Spearman’s rank correlation coefficient was used to assess the correlation between these PET measures and Mini-Mental State Examination (MMSE) scores and duration of symptoms. 11

C-PIB retention. Visual inspection of the late PIB ratio images showed increased uptake in 7 of 14 (50%) subjects with MCI. Quantitative analysis revealed PIB uptake ratio values comparable to our AD group, with twofold increased uptake in cingulate and frontal regions. These seven patients with MCI were therefore considered as a subgroup, having mean ADrange PIB binding which was greater than control mean binding in all cortical ROIs (p ⬍ 0.001). The remaining seven subjects with MCI had normal levels and patterns of cortical PIB uptake, with no mean binding difference in this normal-range subgroup compared to that of controls (p ⫽ 0.69) (table 2). Two of our 22 subjects with AD had regional 11C-PIB uptake within control-range.7 One control (64-year-old man) had increased PIB retention (⬎2 SD greater than control mean) in the anterior cingulate, frontal, and temporal cortex (see discussion). RESULTS

11

C-(R)-PK11195 binding. Coregistration of the PK

BP image with MRI in one subject with MCI who had normal PIB uptake (55-year-old man) was unsatisfactory. He was, therefore, excluded from further PK PET analysis. Repeated measures analysis of variance showed a significant difference (p ⫽ 0.036) between mean PK BPs in AD-PIB range patients with MCI and controls. AD-PIB range patients with MCI had significantly increased mean PK binding in the anterior cingulate, posterior cingulate, and frontal cortex. However, after correction for multiple comparisons, only frontal cortex PK uptake remained significantly raised. There was no difference between mean regional PK binding in the AD-PIB range MCI and AD groups (p ⫽ 0.31), or between normal-PIB range MCI and controls

Table 3

Region of interest 11C-(R)-PK11195 binding potential values in AD, MCI, and controls

AD (n ⴝ 15) Ant cingulate

MCI: AD-range MCI (n ⴝ 13) (n ⴝ 7)

MCI: norm-range* Controls (n ⴝ 6) (n ⴝ 10)

Figure 1

p Value

Scatterplot showing 11C-(R)PK11195 binding potentials in frontal cortex of controls, and mild cognitive impairment (MCI) subgroups; PIB-positive (ⴙve) and PIB-negative (ⴚve) MCI

0.46 ⫾ 0.16 0.48 ⫾ 0.16 0.53 ⫾ 0.19 0.43 ⫾ 0.12 0.41 ⫾ 0.09 0.03

Post cingulate 0.51 ⫾ 0.18 0.54 ⫾ 0.15 0.59 ⫾ 0.16 0.47 ⫾ 0.12 0.45 ⫾ 0.10 0.03 Frontal

0.43 ⫾ 0.11 0.44 ⫾ 0.15 0.48 ⫾ 0.16 0.39 ⫾ 0.14 0.35 ⫾ 0.07 0.02†

Temporal

0.43 ⫾ 0.08 0.43 ⫾ 0.14 0.46 ⫾ 0.13 0.39 ⫾ 0.14 0.37 ⫾ 0.07 0.14

Parietal

0.38 ⫾ 0.11 0.41 ⫾ 0.14 0.43 ⫾ 0.14 0.39 ⫾ 0.16 0.35 ⫾ 0.08 0.10

Whole brain

0.43 ⫾ 0.10 0.44 ⫾ 0.14 0.47 ⫾ 0.14 0.40 ⫾ 0.14 0.37 ⫾ 0.07 0.06

Values ⫽ mean ⫾ SD. *One MCI: normal-range PIB patient excluded (PK PET coregistration unsatisfactory). †The p value is for MCI: AD-range vs controls. p Value significant after correction for multiple comparisons. MCI ⫽ mild cognitive impairment; MCI: AD-range ⫽ mild cognitive impairment: Alzheimer’s disease range PIB; MCI: norm-range ⫽ mild cognitive impairment: normal range PIB; Ant cingulate ⫽ anterior cingulate; Post cingulate ⫽ posterior cingulate.

(p ⫽ 0.67). Grouped mean PK BPs in the subject groups are shown in table 3. Individually, PK binding was increased in 5 of 13 (38%) subjects with MCI, three with AD-range and two with normal-range PIB binding (table e-1 on the Neurology® Web site at www.neurology.org). PK BP values in the MCI subgroups compared to that of controls in the frontal cortex are displayed in figure 1. PET images showing PK binding in patients with MCI are displayed in figure 2. Correlations. We found no correlation between individual regional PK binding and PIB retention in our MCI groups. Additionally, no correlation was found between duration of symptoms or MMSE scores with either PIB retention or PK binding in our AD-PIB range subgroup. However, in the PIB-negative subgroup, lower MMSE scores correlated with higher 11C(R)-PK11195 binding in the anterior cingulate (Spearman rho, ␳ ⫽ ⫺0.812, p ⬍ 0.05) and temporal cortex (Spearman rho, ␳ ⫽ ⫺0.812, p ⬍ 0.05). Follow-up. Five PIB-positive subjects with MCI have been followed for 24 –36 months after their baseline PIB PET scan and 3 (60%) of these have clinically converted to AD. Three PIB-negative MCI subjects have also been followed up for 2–3 years and none have converted to AD, although they continue to fulfill the criteria for a diagnosis of MCI. These three include the two MCI subjects with regionally increased PK binding but normal PIB uptake.

In this combined 11C-PIB and 11C(R)-PK11195 PET study, we found that 7 (50%) of our 14 subjects with amnestic MCI had evidence of increased amyloid deposition. This is consistent with neuropathologic studies which report A␤ deposition in a significant proportion of subjects with MCI,29,30 DISCUSSION

The dotted horizontal line shows controls’ mean ⫹ 2 SD.

and with the concept that amyloid deposition occurs early in the clinical evolution to AD. During a 2–3year follow-up, three out of five of our PIB-positive but no PIB negative patients with MCI have converted to clinically probable AD. A longitudinal follow-up of the MCI cohort is ongoing. Only one of 14 healthy controls showed increased PIB retention; this targeted the anterior cingulate and frontal and temporal cortices. Increased amyloid deposition has been reported in 10% of elderly healthy adults31 and its prevalence increases with age. Our relatively young control group (mean age 63.9 years; SD 5.3) might account for the low prevalence of significant PIB retention in our controls. Compared to controls, our patients with MCI with increased PIB retention had significantly higher mean levels of cortical PK binding, although, after correction for multiple comparisons, only frontal PK uptake remained significantly raised, probably reflecting the low power of our small series. We detected regional increases in PK binding in our patients with MCI less frequently than raised PIB binding and there are a number of possible explanations for this. First, the specific signal associated with 11 C-(R)-PK11195 uptake is low compared with 11CPIB uptake, in part due to the lower density of actiNeurology 72

January 6, 2009

59

Figure 2

11 C-(R)-PK11195 binding potentials and corresponding PIB ratio images in two patients with PIBpositive mild cognitive impairment (MCI)

MCI-I has normal PK binding and MCI-II has increased PK binding.

vated microglia compared with amyloid plaques, as seen in AD,32 and also the higher background nonspecific signal seen with PK compared to that seen with 11C-PIB. This may have resulted in false negative findings in some patients. When delineating ROIs, we used a probabilistic atlas that takes into account variations in individual brain structures and atrophy. However, a limitation of this study is that we did not formally perform partial volume correction. This also may have resulted in an underestimation of cortical PK binding and false negative findings. Against this, we detected increased binding in the anterior and posterior cingulate, relatively small structures compared to our other interrogated ROIs. Finally, evidence exists for multiple factors 60

Neurology 72

January 6, 2009

apart from A␤ that may influence reactivity of microglia within brain, for example ApoE4 status33 and region-specific differences in the reactivity of microglial populations.34 We did not perform apolipoprotein E genotyping in our subjects. Different ApoE alleles influence amyloid load and so future PET studies may allow the interaction between ApoE genotype, amyloid deposition, and microglial activation to be explored in vivo. An early 11C-PK11195 PET study in patients with AD with a lower sensitivity PET camera failed to detect increased binding compared to controls.35 However, there are a number of important methodologic differences between that and the present study. First, they used a cerebellar reference region where specific binding

can be found. This may have led to apparent absent binding in other brain areas. Second, their control group consisted predominantly of patients with small cerebral gliomas which can bind PK. Third, they used racemic PK11195 whereas we used the active (R)enantiomer of PK11195 which has been shown to bind PK binding sites with nanomolar affinity.36 More recently, SPECT15 and PET14 studies in patients with AD demonstrated significant increases in cortical PK binding, confirming this tracer is capable of detecting microglial activation in vivo. The PET study14 included one patient with isolated memory impairment who demonstrated increased binding in subregions of the temporal lobe, although 18F-FDG PET was normal at this time, suggesting that microglial activation can occur before metabolic deficits become evident, a viewpoint that is backed up by a histopathologic study in patients with AD.37 Here, microglial activation along with A␤ and congophilic deposits were found in the middle frontal gyrus in the absence of neurofibrillary tangles. These observations and our finding of comparable levels of PK binding in our PIB-positive MCI and AD group provide a rationale for assessing microglial activation in patients with MCI, a significant proportion of whom already have amyloid deposition at the time of clinical presentation. We found no correlation between individual levels of amyloid deposition, as measured by 11C-PIB PET, and microglial activation, as assessed by 11C(R)-PK11195 PET. This is in contrast to immunohistochemistry studies which have found activated microglial cells clustered at sites of neuritic plaques. However, it has also been demonstrated that not all amyloid plaques are associated with surrounding microglia,38 again implying that multiple factors may be involved in microglial activation as a response to amyloid pathology. Additionally, we found no correlation between MMSE scores or disease duration with PIB retention and PK binding in our PIBpositive subgroup. It is likely, however, that MMSE and other neuropsychometry measures in these patients are influenced by additional pathology such as the presence or absence of neurofibrillary tangles. The recent development of higher affinity PET radioligands which bind to the PBBS, such as 11CDAA110639 and 11C-vinpocetine,40 may provide greater sensitivity for assessing and quantifying microglial activation in cognitive impairment and allow one to further explore the relationship between microglial activation, fibrillar amyloid, and cognition. The follow-up of PIB-positive patients with MCI with in vivo PBBS markers will enable a better understanding of the time course of microglial activation and its significance as a predictor of clinical progression to AD, and provide the opportunity to

monitor the pathophysiologic effects of antiinflammatory agents in vivo. Finally, two subjects with MCI with increased PK binding had normal PIB uptake. The first patient (MCI-5) was a 70-year-old woman who had small focal increases in PK binding in the frontal and parietal cortices. Since her symptoms began 5 years ago she has shown no progression in her symptoms, supported by annual clinical, neuropsychological, and neuroimaging assessments. While these do not suggest a neurodegenerative cause for her memory impairment, her diagnosis, and the cause for the PK findings, remains unclear. Continued follow-up will be important in assessing its significance. The second patient (MCI-3), who had increased PK binding in all cortical regions of interest, was a 74-year-old man with a history of memory impairment dating back at least 5 years. This was associated with ventricular enlargement on magnetic resonance neuroimaging but annual clinical and neuropsychological assessments showed no convincing progression over this time. Subsequently he suffered a subacute deterioration in his cognition associated with increasing ventricular enlargement. A ventriculoperitoneal shunt was inserted which led to an improvement in his symptoms. An underlying neurodegenerative condition, again, seems unlikely given the long period of stability in his symptoms. A more definitive diagnosis has not yet been made and it remains to be seen whether shunting remains beneficial over the long term. ACKNOWLEDGMENT The authors thank Hope McDevitt, Andreanna Williams, James Anscombe, and Andrew Blyth for help with scanning.

Received July 1, 2008. Accepted in final form September 25, 2008.

REFERENCES 1. Petersen RC, Doody R, Kurz A, et al. Current concepts in mild cognitive impairment. Arch Neurol 2001;58:1985– 1992. 2. Klunk WE, Wang Y, Huang GF, et al. The binding of 2-(4=-methylaminophenyl)benzothiazole to postmortem brain homogenates is dominated by the amyloid component. J Neurosci 2003;23:2086–2092. 3. Klunk WE, Engler H, Nordberg A, et al. Imaging brain amyloid in Alzheimer’s disease with Pittsburgh Compound-B. Ann Neurol 2004;55:306–319. 4. Lopresti BJ, Klunk WE, Mathis CA, et al. Simplified quantification of Pittsburgh Compound B amyloid imaging PET studies: a comparative analysis. J Nucl Med 2005; 46:1959–1972. 5. Price JC, Klunk WE, Lopresti BJ, et al. Kinetic modeling of amyloid binding in humans using PET imaging and Pittsburgh Compound-B. J Cereb Blood Flow Metab 2005;25:1528–1547. 6. Archer HA, Edison P, Brooks DJ, et al. Amyloid load and cerebral atrophy in Alzheimer’s disease: an 11C-PIB Neurology 72

January 6, 2009

61

7.

8.

9.

10.

11.

12.

13.

14.

15.

16.

17.

18.

19.

20. 21.

22.

23.

62

positron emission tomography study. Ann Neurol 2006; 60:145–147. Edison P, Archer HA, Hinz R, et al. Amyloid, hypometabolism, and cognition in Alzheimer disease: an [11C]PIB and [18F]FDG PET study. Neurology 2007;68:501–508. Rowe CC, Ng S, Ackermann U, et al. Imaging betaamyloid burden in aging and dementia. Neurology 2007; 68:1718–1725. Forsberg A, Engler H, Almkvist O, et al. PET imaging of amyloid deposition in patients with mild cognitive impairment. Neurobiol Aging 2008;29:1456–1465. Kemppainen NM, Aalto S, Wilson IA, et al. PET amyloid ligand [11C]PIB uptake is increased in mild cognitive impairment. Neurology 2007;68:1603–1606. Haga S, Akai K, Ishii T. Demonstration of microglial cells in and around senile (neuritic) plaques in the Alzheimer brain. An immunohistochemical study using a novel monoclonal antibody. Acta Neuropathol (Berl) 1989;77:569–575. Meyer-Luehmann M, Spires-Jones TL, Prada C, et al. Rapid appearance and local toxicity of amyloid-beta plaques in a mouse model of Alzheimer’s disease. Nature 2008;451:720–724. Banati RB, Newcombe J, Gunn RN, et al. The peripheral benzodiazepine binding site in the brain in multiple sclerosis: quantitative in vivo imaging of microglia as a measure of disease activity. Brain 2000;123:2321–2337. Cagnin A, Brooks DJ, Kennedy AM, et al. In-vivo measurement of activated microglia in dementia. Lancet 2001; 358:461–467. Versijpt JJ, Dumont F, Van Laere KJ, et al. Assessment of neuroinflammation and microglial activation in Alzheimer’s disease with radiolabelled PK11195 and single photon emission computed tomography: a pilot study. Eur Neurol 2003;50:39–47. Cagnin A, Rossor M, Sampson EL, Mackinnon T, Banati RB. In vivo detection of microglial activation in frontotemporal dementia. Ann Neurol 2004;56:894–897. Gerhard A, Pavese N, Hotton G, et al. In vivo imaging of microglial activation with [11C](R)-PK11195 PET in idiopathic Parkinson’s disease. Neurobiol Dis 2006;21:404–412. Ard MD, Cole GM, Wei J, Mehrle AP, Fratkin JD. Scavenging of Alzheimer’s amyloid beta-protein by microglia in culture. J Neurosci Res 1996;43:190–202. Paresce DM, Chung H, Maxfield FR. Slow degradation of aggregates of the Alzheimer’s disease amyloid beta-protein by microglial cells. J Biol Chem 1997;272:29390–29397. McGeer PL, McGeer EG. Inflammation, autotoxicity and Alzheimer disease. Neurobiol Aging 2001;22:799–809. McKhann G, Drachman D, Folstein M, Katzman R, Price D, Stadlan EM. Clinical diagnosis of Alzheimer’s disease: report of the NINCDS-ADRDA Work Group under the auspices of Department of Health and Human Services Task Force on Alzheimer’s Disease. Neurology 1984;34: 939–944. Hammers A, Allom R, Koepp MJ, et al. Three-dimensional maximum probability atlas of the human brain, with particular reference to the temporal lobe. Hum Brain Mapp 2003; 19:224–247. Joachim CL, Morris JH, Selkoe DJ. Diffuse senile plaques occur commonly in the cerebellum in Alzheimer’s disease. Am J Pathol 1989;135:309–319.

Neurology 72

January 6, 2009

24.

25. 26.

27.

28.

29.

30.

31.

32.

33.

34.

35.

36.

37.

38.

39.

40.

Gunn RN, Lammertsma AA, Hume SP, Cunningham VJ. Parametric imaging of ligand-receptor binding in PET using a simplified reference region model. Neuroimage 1997;6:279–287. Larner AJ. The cerebellum in Alzheimer’s disease. Dement Geriatr Cogn Disord 1997;8:203–209. Anderson AN, Pavese N, Edison P, et al. A systematic comparison of kinetic modelling methods generating parametric maps for [(11)C]-(R)-PK11195. Neuroimage 2007;36:28–37. Turkheimer FE, Edison P, Pavese N, et al. Reference and target region modeling of [11C]-(R)-PK11195 brain studies. J Nucl Med 2007;48:158–167. Turkheimer FE, Smith CB, Schmidt K. Estimation of the number of “true” null hypotheses in multivariate analysis of neuroimaging data. Neuroimage 2001;13:920–930. Markesbery WR, Schmitt FA, Kryscio RJ, Davis DG, Smith CD, Wekstein DR. Neuropathologic substrate of mild cognitive impairment. Arch Neurol 2006;63:38–46. Petersen RC, Parisi JE, Dickson DW, et al. Neuropathologic features of amnestic mild cognitive impairment. Arch Neurol 2006;63:665–672. Mintun MA, Larossa GN, Sheline YI, et al. [11C]PIB in a nondemented population: potential antecedent marker of Alzheimer disease. Neurology 2006;67:446–452. Nagele RG, Wegiel J, Venkataraman V, Imaki H, Wang KC, Wegiel J. Contribution of glial cells to the development of amyloid plaques in Alzheimer’s disease. Neurobiol Aging 2004;25:663–674. Lombardi VR, Garcia M, Cacabelos R. Microglial activation induced by factor(s) contained in sera from Alzheimer-related ApoE genotypes. J Neurosci Res 1998; 54:539–553. Mittelbronn M, Dietz K, Schluesener HJ, Meyermann R. Local distribution of microglia in the normal adult human central nervous system differs by up to one order of magnitude. Acta Neuropathol 2001;101:249–255. Groom GN, Junck L, Foster NL, Frey KA, Kuhl DE. PET of peripheral benzodiazepine binding sites in the microgliosis of Alzheimer’s disease. J Nucl Med 1995;36:2207–2210. Shah F, Hume SP, Pike VW, Ashworth S, McDermott J. Synthesis of the enantiomers of [N-methyl-11C]PK 11195 and comparison of their behaviours as radioligands for PK binding sites in rats. Nucl Med Biol 1994;21:573–581. Arends YM, Duyckaerts C, Rozemuller JM, Eikelenboom P, Hauw JJ. Microglia, amyloid and dementia in Alzheimer disease. A correlative study. Neurobiol Aging 2000; 21:39–47. Streit WJ. Microglia and neuroprotection: implications for Alzheimer’s disease. Brain Res Brain Res Rev 2005;48: 234–239. Venneti S, Wagner AK, Wang G, et al. The high affinity peripheral benzodiazepine receptor ligand DAA1106 binds specifically to microglia in a rat model of traumatic brain injury: implications for PET imaging. Exp Neurol 2007;207:118–127. Vas A, Shchukin Y, Karrenbauer VD, et al. Functional neuroimaging in multiple sclerosis with radiolabelled glia markers: Preliminary comparative PET studies with [(11)C]vinpocetine and [(11)C]PK11195 in patients. J Neurol Sci 2008;264:9–17.

Diagnostic utility of different MRI and MR angiography measures in Fabry disease

A. Fellgiebel, MD, PhD I. Keller, MD D. Marin M.J. Mu¨ller, MD, PhD I. Schermuly, PhD I. Yakushev J. Albrecht, MD H. Bellha¨user M. Kinateder M. Beck, MD, PhD P. Stoeter, MD, PhD

Address correspondence and reprint requests to Dr. A. Fellgiebel, Department of Psychiatry, University Hospital of Mainz, Untere Zahlbacher Str. 8, 55131 Mainz, Germany [email protected]. uni-mainz.de

ABSTRACT

Background: Neurologic hallmarks of Fabry disease (FD) include small fiber neuropathy as well as cerebral micro- and macroangiopathy with premature stroke. Cranial MRI shows progressive white matter lesions (WML) at an early age, increased signal intensity in the pulvinar, and tortuosity and dilatation of the larger vessels. To unravel the most promising imaging tool for the detection of CNS involvement in FD we compared the diagnostic utility of the different MR imaging findings.

Methods: Twenty-five clinically affected patients with FD (age 36.5 ⫾ 11.0) and 20 age-matched controls were investigated by structural MRI, MR angiography, and diffusion tensor imaging (DTI). Individual WML volumes, global mean diffusivity (MD), and mean cerebral artery diameters were determined. Results: Using receiver operating characteristic analyses, enlarged diameters of the following cerebral arteries significantly separated patients with FD from controls: middle cerebral artery: area under curve (AUC) ⫽ 0.75, p ⫽ 0.005; posterior cerebral artery: AUC ⫽ 0.69, p ⫽ 0.041; carotid artery: 0.69, p ⫽ 0.041; basilar artery: AUC ⫽ 0.96, p ⬍ 0.0005. A total of 87% of the individuals were correctly classified by basilar artery diameters (sensitivity 95%, specificity 83%). WML volumes and global MD values did not significantly separate patients from controls.

Conclusions: With an accuracy of 87%, basilar artery diameters were superior to all other MR measures for separating patients with Fabry disease (FD) from controls. Future studies should adopt basilar artery measurements for early detection and monitoring of brain involvement in FD. Moreover, further investigations should reveal if the dilated vasculopathy in FD could be a screening marker to detect FD in a cohort of other cerebrovascular diseases, especially in cryptogenic stroke. Neurology® 2009;72:63–68 GLOSSARY AUC ⫽ area under curve; CI ⫽ confidence interval; DTI ⫽ diffusion tensor imaging; ERT ⫽ enzyme replacement therapy; FA ⫽ fractional anisotropy; FD ⫽ Fabry disease; FLAIR ⫽ fluid-attenuated inversion recovery; MD ⫽ mean diffusivity; ROC ⫽ receiver operating characteristic; ROI ⫽ region of interest; TE ⫽ echo time; TOF ⫽ time-of-flight; TR ⫽ repetition time; WML ⫽ white matter lesions.

Fabry disease (FD) is a rare inherited multisystemic lysosomal storage disorder.1 Due to deficient activity of the enzyme ␣-galactosidase A, neutral glycosphingolipids, mainly globotriaosylceramide (Gb3), accumulate in various organ systems.2 Lipid deposits occur preferentially in vascular endothelial and smooth muscle cells, resulting in vascular dysfunction, vessel occlusion, and tissue ischemia. Clinical signs and symptoms of FD include cutaneous angiokeratomas, corneal dystrophy (cornea verticillata), hypohidrosis, gastrointestinal disturbances, renal dysfunction, and cardiac disease (especially left ventricular hypertrophy). The neurologic hallmarks include small fiber neuropathy as well as cerebral micro- and macroangiopathy with substantially higher risk of stroke.3 CNS involvement is a major burden in FD. Conventional cranial MRI shows micro- and macroangiopathic changes such as severe and progressive white matter lesions (WML) at an early age on

From the Department of Psychiatry (A.F., I.K., D.M., M.J.M., I.S., I.Y., J.A., H.B., M.K.), Institute of Neuroradiology (I.K., P.S.), and Children’s Hospital of the University of Mainz (M.B.), Germany. Disclosure: The authors report no disclosures. This study is part of the doctoral thesis of Dominik Marin. Copyright © 2009 by AAN Enterprises, Inc.

63

T2- and fluid-attenuated inversion recoveryweighted (FLAIR) images, increased signal intensity in the pulvinar on T1-weighted MRI (pulvinar sign), as well as tortuosity and dilatation of the larger vessels (dolichoectasia).3 Using diffusion-tensor imaging (DTI), a new structural MRI technique that measures water diffusion characteristics, we showed marked brain tissue alterations in FD, predominantly in the periventricular white matter. Even patients with few WML had significantly elevated brain tissue diffusivity.4,5 Though widely accepted as the most prominent MRI finding, measurements of the individual WML volumes in FD are missing. Measurements of the diameters of larger vessels, especially the basilar artery, which has been repeatedly described as pathologically enlarged in FD, have also not been reported.6,7 The aim of the present study was to quantify the known MRI and MR-angio findings in a group of clinically affected patients with genetically proven FD and to compare the diagnostic utility of the different brain structural measures. We abstained from including the pulvinar sign because we observed it only in two men of the FD group, which is in line with the literature.8 Likewise, we did not include the fractional anisotropy (FA) values of the DTI acquisition because we previously could not demonstrate significant differences between FD and controls using global FA measurements.4,5 METHODS Patients. We enrolled 25 clinically affected patients with FD (10 M, 15 F) and 20 healthy controls (9 M, 11 F). Demographic and clinical characteristics are given in table 1. All patients were recruited at the Children’s Hospital, University of Mainz, Germany. For the enzymatic and genetic diagnosis of FD, standard methods were used as generally recommended.9 This study group is part of a larger longitudinal case control study of 40 patients with FD who underwent (baseline and after 18 months) detailed neuropsychological and psychiatric assessments as well as conventional MRI and DTI. Only patients with complete and artifact-free data sets (n ⫽ 25) were included in the present analyses. More details of the enrollment procedure and the clinical characteristics of the patient group have been published previously.5 Except for four women all patients were under enzyme replacement therapy (ERT) during the study period. The study was approved by the local Ethics Committee, and all subjects gave written informed consent.

Measurements. All data were obtained on a 1.5 Tesla system with gradients of 40 mT/m (Magnetom Sonata; Siemens). Apart from the acquisition of routine T1-weighted (repetition time 64

Neurology 72

January 6, 2009

Table 1

Demographic and clinical characteristics of patients and controls Fabry disease

Controls

No. (women)

25 (15)

20 (11)

Age, y

36.5 ⫾ 11.0

36.8 ⫾ 10.0

Cerebrovascular events

5 (20)

0

Neuropathic pain

20 (80)

0

Angiokeratoma

13 (52)

0

Cardiac dysfunction

20 (80)

0

Cardiomyopathy

13 (52)

Cardiac arrhythmias Left ventricular hypertrophy Renal dysfunction Renal insufficiency Proteinuria Serum creatinine (mg/dL)

7 (28) 1 (5) 20 (80)

0

4 (16) 16 (64) 0.92 ⫾ 0.41

Values are n (%) or mean ⫾ standard deviation.

[TR]/echo time [TE]: 600 msec/25 msec, matrix 256 ⫻ 256), PD/T2-weighted (TR/TE 1/TE 2: 4,500 msec/15 msec/100 msec, matrix 256 ⫻ 256), FLAIR-weighted (TR/TE 9,000 msec/108 msec, slice thickness 6 mm, matrix 512 ⫻ 448) images, time-of-flight (TOF) sequences (TR/TE: 40/4.97 msec, slice thickness 0.8 mm, matrix 512 ⫻ 384), and threedimensional MPRAGE (TR/TE: 1,900 msec/16 msec, matrix 512 ⫻ 512) data sets, we used a transverse diffusion-weighted single-shot spin-echo echoplanar based sequence with gradients along six non-collinear directions (TR/TE ⫽ 8,000/105 msec, b ⫽ 0 and 1,000 s/mm2, matrix 128 ⫻ 128, slice thickness 3 mm without gap [voxel size 1.8 ⫻ 1.8 ⫻ 3.0 mm]) and six averages. The transverse slices were aligned to the AC-PC line (anterior–posterior commissure) and covered the whole brain, except the top 6 mm. Diameters of the cerebral arteries were measured within the TOF sequences using ConVis Dicom Viewer software (Version 2.9.6. Pro, 2006). The basilar artery diameter was defined as average of three measuring points: 1) caudal (shortly after the confluence of the vertebral arteries), 2) intermediate (in the middle of the basilar artery), and 3) rostral (just before the bifurcation). Measuring points were determined manually on the sagittal plane. Diameters were measured independently by two experienced raters (I.K., D.M.). The interrater reliability was 0.90 (Spearman rho). The anterior cerebral artery diameter was measured in the middle of the segment A1 perpendicularly to the vessel.10 The middle cerebral artery diameter was determined in the middle of segment M1 perpendicularly to the vessel.11 The posterior cerebral artery diameter was determined in the middle of segment P2 perpendicularly to the vessel. The internal carotid artery diameter was measured in segment C7, within the circle of Willis, 5 mm before the bifurcation into middle and anterior cerebral artery.12 Due to technical artifacts isolated artery diameters were not obtainable in some cases: anterior cerebral artery right (two controls, one patient), anterior cerebral artery left (one control, one patient), carotid artery right (two patients), and carotid artery left (one patient). The overall interrater reliability of all artery measurements was acceptable at 0.80 (Spearman rho). In

Table 2

Group differences Fabry disease, mean ⴞ SD

Controls, mean ⴞ SD

p*

2,026 ⫾ 5,099

150 ⫾ 256

NS†

661 ⫾ 24

0.041‡

Conventional MRI Total WML volume (mm3) DWI Global mean diffusivity

characteristic (ROC) curve analysis was used. The area under the ROC curve (AUC) was estimated with corresponding 95% confidence intervals (95% CI), and cutoff values, sensitivity, specificity, and accuracy (% correctly classified) were calculated across the full range of values. The cutoff was defined as the value with the highest specificity at a sensitivity ⬎70%. All analyses were conducted using SPSS software version 12.0.

Age and gender of patients and controls did not differ significantly. Demographic data and clinical characteristics are given in table 1. Group comparisons of imaging data are shown in table 2. The WML volume data were not normally distributed (Kolmogorov-Smirnov Z-test, p ⬍ 0.0005) and did not differ significantly between patients and controls (Mann-Whitney U test, p ⬎ 0.05). The huge difference of mean WML volumes between patients and controls resulted from only 7 of 25 patients who had markedly elevated WML volumes (i.e., above 662 mm3, which is the mean of controls plus two standard deviations). After exclusion of these 7 patients, the mean WML volumes of patients and controls showed only a small difference (109 vs 104 mm3). Global MD was significantly elevated in FD compared to controls (t test, p ⫽ 0.041). Except for the anterior cerebral artery diameter, all cerebral artery diameters were significantly dilated in patients with FD compared to controls (see table 2). The largest and most significant difference could be detected for the basilar artery diameter (⌬ ⫽ 0.9 mm, p ⱕ 0.0005). In the control group, smaller anterior cerebral artery diameters (Spearman rho ⫽ ⫺0.56; p ⫽ 0.016) and smaller posterior cerebral artery diameters (Spearman rho ⫽ ⫺0.53; p ⫽ 0.016) were correlated with older age. In the patient group, age was only associated with increased total WML volume (Spearman rho ⫽ 0.75, p ⬍ 0.0005) and the global MD (Spearman rho ⫽ 0.46, p ⫽ 0.021). The mean basilar artery diameter was significantly enlarged in men with FD (3.8 ⫾ 0.64 mm) compared to women with FD (3.0 ⫾ 0.1 mm), p ⫽ 0.006. In women with FD, the mean basilar artery diameter was significantly enlarged compared to the women of the normal control group (patients: 3.0 ⫾ 0.31 mm; controls: 2.4 ⫾ 0.33 mm; p ⱕ 0.0005). In men with FD, the mean basilar artery diameter was significantly enlarged compared to the men of the control group (patients: 3.8 ⫾ 0.64 mm; controls: 2.4 ⫾ 0.41 mm; p ⱕ 0.0005). All other measures did not differ significantly between men and women with FD. To assess the group comparisons of younger study subjects separately, we divided patients and controls on the basis of the age median of the study group (37 years) and calculated the group differences for the younger group (age range 20 to 36 years; 12 patients, RESULTS

679 ⫾ 31

MR angiography Anterior cerebral artery diameter (mm)

1.7 ⫾ 0.31

1.5 ⫾ 0.31

NS

Right/left

1.6 ⫾ 0.35/1.7 ⫾ 0.47

1.5 ⫾ 0.37/1.6 ⫾ 0.46

NS/NS

Middle cerebral artery diameter (mm)

2.5 ⫾ 0.23

2.2 ⫾ 0.30

0.003‡

Right/left

2.5 ⫾ 0.29/2.4 ⫾ 0.27

2.2 ⫾ 0.37/2.1 ⫾ 0.26

0.003/0.013

Posterior cerebral artery diameter (mm)

1.6 ⫾ 0.32

1.4 ⫾ 0.31

0.038‡

Right/left

1.6 ⫾ 0.36/1.6 ⫾ 0.3

1.4 ⫾ 0.31/1.4 ⫾ 0.33

NS/0.049

Carotid artery diameter (mm)

2.9 ⫾ 0.48

2.6 ⫾ 0.46

0.019‡

Right/left

2.9 ⫾ 0.6/2.9 ⫾ 0.54

2.6 ⫾ 0.45/2.5 ⫾ 0.56

0.047/0.034

Basilar artery diameter (mm)

3.3 ⫾ 0.59

2.4 ⫾ 0.36

⬍0.0005‡

In case of paired arteries (anterior, media, posterior, carotid), data of the upper row refer to mean diameters of both sides. Mean diffusivity is given as 10– 6 mm2/sec. *p Value (⬍ 0.05). †Mann-Whitney U test. ‡t Test. NS ⫽ not significant; DWI ⫽diffusion-weighted imaging.

case of the paired arteries combined mean diameters of both sides (left and right) were used for statistical analyses. WML volumes were defined as bright lesions (⬎2 mm) of the white matter or basal ganglia and were measured within the FLAIR-weighted images using Analyze Software (Version 8.1; Biomedical Imaging Software System, Mayo Foundation for Medical Education and Research, Rochester, MN). Three experienced operators (I.K., M.K., H.B.) manually traced the WML boundaries slice by slice. Resulting object maps were summed up yielding one total amount of WML volume (mL) per subject. In single cases of marked differences between the raters consensus was achieved after discussion. The overall interrater reliability of the method was acceptable (Spearman rho ⫽ 0.83). Mean diffusivity (MD) was measured within the color-coded DTI maps using Analyze software. The method has been described in detail previously.5 Global MD was calculated as mean value of mean MD within six defined regions of interest (ROIs) which were manually placed within the white matter regions of the anterior, middle, and posterior circulation according to the neuroanatomically defined cerebral blood supply pattern.13

Statistical analyses. Descriptive statistics are shown as mean values and standard deviations. Group comparisons were analyzed using ␹2 test for categorical variables; Mann-Whitney U tests were applied when distributions differed significantly from normal as determined by the Kolmogorov-Smirnov Z-test (p ⬍ 0.05). In case of normal distribution, group differences were analyzed with t tests. Correlations were analyzed with Spearman rank correlation coefficients. To assess the predictive properties of WML volumes, artery diameters, and MD, receiver operating

Neurology 72

January 6, 2009

65

Table 3

Results of receiver operating characteristic (ROC) curve analyses (Fabry disease vs controls)

AUC (95% CI)

p

Sensitivity/ specificity, %

Cutoff values

Accuracy, %

Figure 1

Receiver operating characteristic curves of cerebral artery diameters (Fabry disease, n ⴝ 22 vs controls, n ⴝ 17)

Conventional MRI 0.66 (0.48–0.83)

0.096

71/56

69 mm3

62

0.66 (0.48–0.83)

0.096

76/33

652

60

Anterior cerebral artery diameter

0.68 (0.51–0.86)

0.054

71/67

1.62 mm

69

Middle cerebral artery diameter

0.74 (0.60–0.90)

0.008

71/61

2.33 mm

67

Posterior cerebral artery diameter

0.69 (0.52–0.86)

0.041

71/61

1.47 mm

69

Basilar artery diameter

0.96 (0.81–1.02)

ⱕ0.0005

95/83

2.67 mm

87

Carotid artery diameter

0.62 (0.52–0.86)

0.041

76/67

2.68 mm

67

Total WML volume DWI Global mean diffusivity* MR angiography

In case of paired arteries (anterior, media, posterior, carotid), data refer to mean diameters of both sides. *Mean diffusivity is given as 10– 6 mm2/sec. AUC ⫽ area under the curve; CI ⫽ confidence interval; Accuracy ⫽ % of correctly classified subjects; WML ⫽ white matter lesion; DWI ⫽ diffusion-weighted imaging.

10 controls). The parameter with the largest and most significant difference in the younger group was the basilar artery diameter: the mean diameter in patients was 3.2 ⫾ 0.54 mm; in controls, a mean basilar artery diameter of 2.5 ⫾ 0.46 mm was measured (p ⫽ 0.002). The mean diameter of the middle cerebral artery was also enlarged in the younger patient group compared to younger controls (patients: 2.5 ⫾ 0.19 mm; mean diameter in controls: 2.3 ⫾ 0.25 mm; p ⫽ 0.025). All other measures including WML volume and MD did not differ significantly between younger patients and younger controls. ROC curve analyses were calculated twice: first, to compare the artery diameters. This analysis had six missing values due to technical artifacts interfering with anterior cerebral artery and carotid artery measurements. Second, the basilar artery diameters were plotted together with the global MD and the global WML volumes. Patients with FD could be distinguished significantly from controls using ROC curve analyses of artery diameters (with the exception of the anterior cerebral artery). AUCs, sensitivity, specificity, and accuracy (% of correctly classified subjects) are shown in table 3 (see also figures 1 and 2). The most powerful parameter to separate patients with FD from controls was the mean basilar artery diameter (AUC ⫽ 0.96; sensitivity ⫽ 95%, specificity ⫽ 83%; accuracy ⫽ 87%). Due to technical artifacts, the determination of anterior cerebral artery and carotid artery was not possible in 6 cases (figure 1). 66

Neurology 72

January 6, 2009

Six missing due to technical artifacts (anterior cerebral artery and carotid artery).

Significant correlations could be found between residual peripheral ␣-galactosidase enzyme activity and the obtained MRI and MR angiography measures neither in men nor in women with FD. Over the past several years, new research findings have led to increasing attention to the CNS manifestations of FD.3,14 A high frequency of WML has been described repeatedly in young adult patients with FD. In a longitudinal study of 50 patients with FD, 50% of the patients (mean age of 33 years) had WML.15 Although FD is an X-linked disease, the severity of WML at least in a subgroup of

DISCUSSION

Figure 2

Receiver operating characteristic curves of basilar artery diameter, global mean diffusivity (MD), and total white matter lesion (WML) volume (Fabry disease, n ⴝ 25 vs controls, n ⴝ 20)

clinically affected women seems to be comparable to that of men.16 WML that can be regarded as a risk factor for stroke17 have been described qualitatively or semiquantitatively using WML rating scales.3,16 Unlike WML, however, the degree of macroangiopathic changes in FD has not been quantified yet. Moreover, quantitative comparisons of the different MR findings in FD are lacking. The most important and at the same time unexpected finding of the present study was that basilar artery diameters were clearly superior to WML load as well as to global white matter diffusivity measurements (using DTI) for the separation of FD from controls within the study group. We further demonstrated that except for the anterior cerebral artery, all larger vessels of the circle of Willis were significantly dilated compared to those of agematched normal controls. However, the most evident large vessel pathology was clearly observed at the basilar artery. Our data are thus consistent with previous qualitative studies that reported a particular involvement of the posterior circulation arteries in FD.6,7,14,18 The frequent alteration of the basilar artery morphology has been documented as well repeatedly.7 Whereas a number of etiologic factors of the FD-associated macroangiopathy has been suggested,6 the nature of macroangiopathy in FD, especially the pronounced involvement of the basilar artery, is unclear. It would be reasonable to expect that the enzymopathy affects the larger cerebral arteries in a more symmetric manner. One can speculate that vascular autoregulation is one leading mechanism for the dilatation of the larger brain vessels and leads, possibly due to secondary hemodynamic changes, e.g., increased cerebral blood flow, to a pronounced involvement of the basilar artery.19-22 Surprisingly, using ROC analysis no significant separation of patients and controls could be achieved by WML volume or global diffusivity measurements. WML load, which has been highlighted repeatedly as the most important MR finding in FD, also did not differ significantly between patients and controls. The groups could not be separated because only a relatively small subgroup of seven patients with FD at this age group (median age 37 years) shows significant WML and, conversely, mild WML can be detected in normal controls. Unlike WML volumes, MD was significantly elevated in FD. However, the comparison of the different MR imaging measures showed that basilar artery diameters were much more sensitive and more specific to detect brain involvement related to FD. We previously investigated patients with FD using DTI and showed a significant global increase of

MD that was pronounced in the periventricular regions, even in patients without an increased WML load. Therefore, in comparison with WML load, we recommended diffusivity measurements as a more sensitive structural imaging tool to detect and quantify brain involvement in FD at an early stage of the disease.4,5 The present findings suggest that the basilar artery diameter is markedly superior even to diffusivity for the detection of brain involvement in FD. This notion is also supported by our analysis of the subgroup of younger study subjects (under 37 years of age), in which only the basilar artery diameters and the middle cerebral artery diameters differed significantly between patients and controls, again with a clear emphasis on the basilar artery. The basilar artery diameters were also significantly enlarged in men compared to women with FD which is in line with the frequent observation that CNS manifestations of FD are usually more consistently seen and occur several years earlier in men compared to women.3,18 ERT is available and showed beneficial effects on renal, cardiac, and peripheral nerve function in FD.23 Although increased cerebral blood flow in FD could be reversed under ERT,24 it is unknown if ERT can reduce the progression of brain structural alterations or the probability of consecutive cerebrovascular events. To answer these questions, longitudinal imaging studies including young patients under ERT as well as longitudinal natural history studies of untreated patients are highly desirable. While isolated artery diameters (in three patients and three controls) could not be determined due to technical artifacts, namely within the A1 segment of the anterior cerebral artery and the segment C7 of the carotid artery, the measurement of the basilar artery was technically unproblematic, not timeconsuming, and highly reliable. Together with the high diagnostic accuracy of 87% (sensitivity of 95% at a specificity of 83%) compared to the other applied MR measures which were all below 70% the basilar artery diameter seems to be a favorable and easily obtainable tool to screen for brain involvement even in younger patients with FD and possibly to monitor the development of the disease. Moreover, further investigations should reveal if the dilated vasculopathy in FD can be a screening marker to detect FD in a cohort of other cerebrovascular diseases, especially in cryptogenic stroke. Received June 17, 2008. Accepted in final form September 18, 2008. REFERENCES 1. Meikle PJ, Hopwood JJ, Clague AE, Carey WF. Prevalence of lysosomal storage disorders. JAMA 1999;281: 249–254. Neurology 72

January 6, 2009

67

2.

3. 4.

5.

6.

7. 8.

9.

10.

11.

12.

13.

68

Mehta A, Ricci R, Widmer U, et al. Fabry disease defined: baseline clinical manifestations of 366 patients in the Fabry Outcome Survey. Eur J Clin Invest 2004;34:236– 242. Fellgiebel A, Mu¨ller MJ, Ginsberg L. CNS manifestations of Fabry’s disease. Lancet Neurol 2006;5:791–795. Fellgiebel A, Mazanek M, Whybra C, et al. Pattern of microstructural brain tissue alterations in Fabry disease: a diffusiontensor imaging study. J Neurol 2006;253:780–787. Albrecht J, Dellani PR, Mu¨ller MJ, et al. Voxel based analyses of diffusion tensor imaging in Fabry disease. J Neurol Neurosurg Psychiatry 2007;78:964–969. Moore DF, Kaneski CR, Askari H, Schiffmann R. The cerebral vasculopathy of Fabry disease. J Neurol Sci 2007; 257:258–263. Mitsias P, Levine SR. Cerebrovascular complications of Fabry’s disease. Ann Neurol 1996;40 :8–17. Moore DF, Ye F, Schiffmann R, Butman JA. Increased signal intensity in the pulvinar on T1-weighted images: a pathognomonic MR imaging sign of Fabry disease. AJNR Am J Neuroradiol 2003;24:1096–1101. Desnick RJ, Brady R, Barranger J, et al. Fabry disease, an under-recognized multisystemic disorder: expert recommendations for diagnosis, management, and enzyme replacement therapy. Ann Intern Med 2003;138:338–346. Villablanca JP, Nael K, Habibi R, Nael A, Laub G, Finn JP. 3 T contrast-enhanced magnetic resonance angiography for evaluation of the intracranial arteries: comparison with time-of-flight magnetic resonance angiography and multislice computed tomography angiography. Invest Radiol 2006;41:799–805. Tarasow E, Abdulwahed Saleh Ali A, Lewszuk A, Walecki J. Measurements of the middle cerebral artery in digital subtraction angiography and MR angiography. Med Sci Monit 2007;13 Suppl 1:65–72. Anderson CM, Lee RE, Levin DL, de la Torre Alonso S, Saloner D. Measurement of internal carotid artery stenosis from source MR angiograms. Radiology 1994;193:219– 226. Kretschmann WJ, Weinrich W. Klinische Neuroanatomie und kranielle Bilddiagnostik. 2. ed. Stuttgart: Thieme Verlag; 1991.

Neurology 72

January 6, 2009

14.

15.

16.

17.

18.

19.

20.

21.

22.

23.

24.

Rolfs A, Bottcher T, Zschiesche M, et al. Prevalence of Fabry disease in patients with cryptogenic stroke: a prospective study. Lancet 2005;366:1794–1796. Crutchfield KE, Patronas NJ, Dambrosia JM, et al. Quantitative analysis of cerebral vasculopathy in patients with Fabry disease. Neurology 1998;50:1746–1749. Fellgiebel A, Mu¨ller MJ, Mazanek M, Baron K, Beck M, Stoeter P. White matter lesion severity in male and female patients with Fabry disease. Neurology 2005;65: 600–602. Bisschops RH, van der Graaf Y, Mali WP, van der Grond J. High total cerebral blood flow is associated with a decrease of white matter lesions. J Neurol 2004;251:1481– 1485. Gupta S, Ries M, Kotsopoulos S, Schiffmann R. The relationship of vascular glycolipid storage to clinical manifestations of Fabry disease: a cross-sectional study of a large cohort of clinically affected heterozygous women. Medicine 2005;84:261–268. Hilz MJ, Kolodny EH, Brys M, Stemper B, Haendl T, Marthol H. Reduced cerebral blood flow velocity and impaired cerebral autoregulation in patients with Fabry disease. J Neurol 2004;251:564–570. Moore DF, Altarescu G, Barker WC, Patronas NJ, Herscovitch P, Schiffmann R. White matter lesions in Fabry disease occur in ‘prior’ selectively hypometabolic and hyperperfused brain regions. Brain Res Bull 2003; 62:231–240. Moore DF, Herscovitch P, Schiffmann R. Selective arterial distribution of cerebral hyperperfusion in Fabry disease. J Neuroimaging 2001;11:303–307. Moore DF, Scott LT, Gladwin MT, et al. Regional cerebral hyperperfusion and nitric oxide pathway dysregulation in Fabry disease: reversal by enzyme replacement therapy. Circulation 2001;104:1506–1512. Beck M, Ricci R, Widmer U, et al. Fabry disease: overall effects of agalsidase alfa treatment. Eur J Clin Invest 2004; 34:838–844. Moore DF, Altarescu G, Ling GS, et al. Elevated cerebral blood flow velocities in Fabry disease with reversal after enzyme replacement. Stroke 2002;33:525–531.

Smoking and family history and risk of aneurysmal subarachnoid hemorrhage

D. Woo, MD J. Khoury, PhD M.M. Haverbusch, RN P. Sekar, MS M.L. Flaherty, MD D.O. Kleindorfer, MD B.M. Kissela, MD C.J. Moomaw, PhD R. Deka, PhD J.P. Broderick, MD

Address correspondence and reprint requests to Dr. Daniel Woo, Department of Neurology, University of Cincinnati College of Medicine, 260 Stetson Street ML 0525, Cincinnati, OH 45267-0525 [email protected].

ABSTRACT

Objective: Smoking and family history of aneurysmal subarachnoid hemorrhage (aSAH) are independent risk factors for aSAH. Using a population-based case-control study of hemorrhagic stroke, we hypothesized that having both a first-degree relative with a brain aneurysm or SAH (⫹FH) and current smoking interact to increase the risk of aSAH.

Methods: Cases of aneurysmal SAH were prospectively recruited from all 17 hospitals in the five-county region around the University of Cincinnati. Controls were identified by random digit dialing. Controls were matched to cases of aSAH by age (⫾5 years), race, and sex. Conditional multiple logistic regression was used to identify independent risk factors. For deviation from the additive model, the interaction constant ratio test was used. Results: A total of 339 cases of aSAH were matched to 1,016 controls. Compared to current nonsmokers with no first-degree relatives with aSAH (⫺FH), the odds ratio (OR) for aSAH for current nonsmokers with ⫹FH was 2.5 (95% confidence interval [CI] 0.9 – 6.9); for current smokers with ⫺FH, OR ⫽ 3.1 (95% CI 2.2– 4.4); and for current smokers with ⫹FH, OR ⫽ 6.4 (95% CI 3.1–13. 2). The interaction constant ratio, which measured the deviation from the additive model, was significant: 2.19 (95% CI 0.80 –5.99). The lower bound of the 95% CI ⬎0.5 signifies a departure from the additive model. Conclusion: Evidence of a gene– environment interaction with smoking exists for aneurysmal subarachnoid hemorrhage. This finding is important to counseling family members and for screening of intracranial aneurysm (IA) as well as the design and interpretation of genetic epidemiology of IA studies. Neurology® 2009;72:69–72 GLOSSARY aSAH ⫽ aneurysmal subarachnoid hemorrhage; CI ⫽ confidence interval; GERFHS ⫽ Genetic and Environmental Risk Factors of Hemorrhagic Stroke; IA ⫽ intracranial aneurysm; ICH ⫽ intracerebral hemorrhage; ICR ⫽ interaction contrast ratio; OR ⫽ odds ratio.

One of the challenges in genetic epidemiology of complex traits is identification of gene– environment interactions. Environmental and behavioral factors may be necessary for triggering the manifestation of risk or benefit of some genetic variations, or enhancing the effect. Current and past smoking has been consistently found to be associated with aneurysmal subarachnoid hemorrhage (aSAH) and is considered to be the most significant modifiable risk factor for aSAH.1,2 In population-based or cohort studies, 70 –75% of persons with SAH have a history of smoking, and 50 – 60% are current smokers.1,2 Smoking behavior is known to aggregate within families, and similarly, a family history of brain aneurysm or aSAH have been found to aggregate within families, independent of smoking.1,3,4 However, few studies have explored the possibility that current smoking and a positive family history may interact to further increase the risk of aSAH than their individual risks. Such evidence for a gene– environment interaction may have significant implications for

From the University of Cincinnati Department of Neurology (D.W., M.M.H., M.L.F., D.O.K., B.M.K., C.J.M., J.P.B.), Cincinnati Children’s Hospital Medical Center–Center for Epidemiology and Biostatistics (J.K.), and University of Cincinnati Department of Environmental Health (P.S., R.D.), OH. Funded by a grant from the NIH (National Institute of Neurological Disorders and Stroke NS36695). Disclosure: The authors report no disclosures. Copyright © 2009 by AAN Enterprises, Inc.

69

Table 1

these risk factors was greater than additive in risk.

Subject characteristics

Variable

Cases (n ⴝ 339)

Controls (n ⴝ 1,016)

Age, y

51.2 ⫾ 12.9

51.6 ⫾ 12.8

Female

229 (67.6)

687 (67.6)

African American

70 (20.7)

209 (20.6)

Body mass index

26.9 ⫾ 6.3

28.9 ⫾ 7.3*

Current smoking

211 (62.2)

296 (29.1)*

Former smoking

54 (15.9)

311 (30.6)

Never smoking

74 (21.8)

409 (40.3)

Family history of subarachnoid hemorrhage or brain aneurysm (first-degree relative)

37 (11.0)

42 (4.1)*

History of diabetes History of hypertension

22 (6.5)

108 (10.6)

163 (48.1)

381 (37.5)*

Frequent alcohol use

42 (12.4)

46 (4.5)*

High school education

134 (39.5)

547 (53.8)

Matched analysis for all except age, gender, and race. Data expressed as mean ⫾ standard deviation or n (%). *p ⬍ 0.001.

screening family members of patients with an aneurysmal SAH, analysis of genetic association studies, and counseling of family members regarding smoking behavior. An additive or “no interaction” relationship between risk factors is one in which the presence of both factors yields a risk that is equivalent to adding the individual risks together. An interaction occurs when the presence of both factors leads to a greater (or lesser) risk of the outcome than simply adding the individual risks. For most interactions, however, a minority of cases will have both risk factors (without bias, roughly equivalent to the prevalence of each factor multiplied together). Thus, the power to identify interactions using traditional logistic regression methods is limited in power as a function of the analytical technique. Newer methods to identify interactions seek to identify a significant departure from the additive model. We used the interaction constant ratio as described in Methods and estimated the 95% confidence interval (CI) of the result to determine significance. We hypothesized that current smoking and having a first-degree relative were independent risk factors and that the coexistence of 70

Neurology 72

January 6, 2009

METHODS The methods of the Genetic and Environmental Risk Factors of Hemorrhagic Stroke (GERFHS) Study (National Institute of Neurological Disorders and Stroke: NS36695) have been published previously.5,6 Institutional Review Board approval was obtained from all participating hospitals and informed consent was obtained from all subjects. HIPAA authorization was obtained from all subjects after April 2003. All patients with a potential intracerebral hemorrhage (ICH) or SAH who reside within 50 miles of the University of Cincinnati are identified by surveillance of hospital emergency and radiology departments and hospital discharge diagnoses. Aneurysmal SAH was identified in patients with SAH by review of neuroimaging, including CT, MRI, and angiography scanning. Intracranial aneurysms (IA) were identified by CTA or MRA if ⬎4 mm, by cerebral angiography, or at autopsy. Fusiform aneurysms, aneurysms related to arteriovenous malformations, and subarachnoid hemorrhage related to trauma or brain tumor were excluded. Patients were eligible if ⱖ18 years of age. A subset of cases consented to direct interview and genetic sampling (50% of all cases). This subset was previously reported to be similar to non-interviewed cases with respect to major risk factors such as smoking history and family history of aSAH by chart abstraction.1 If a patient was unable to be interviewed, a proxy was interviewed (99 cases). If the case agreed to be interviewed, two matched controls (age ⫾ 5 years, race, and gender), identified by random digit dialing (50% response rate of potential participants meeting demographic criteria), underwent an identical interview that included smoking history, average packyears, and family history of brain aneurysm or subarachnoid hemorrhage. As part of the overall GERFHS study, ICH cases also had been interviewed and matched to controls. To maximize power for the current analysis by using three controls for each case, an extra control from the pool of ICH controls, if available, was matched to each aSAH case. Statistical analysis was done using SAS, version 9.1 (SAS Institute, Cary, NC). A mixed general linear model and conditional logistic regression were used, as appropriate, to compare cases to controls for the continuous and categorical variables. As the study design involved matching, all analyses involved the use of statistical methods for matched data. In order to investigate the effect of family history of a first-degree relative with SAH or IA and current smoking status on aSAH, conditional multiple logistic regression was used. The initial model included a multiplicative interaction term; then further modeling incorporated dummy variables that defined an additive interaction. The reference condition for the additive interaction was no family history and no current smoking. The methodology described by Botto and Khoury7 was used for examination of the multiplicative and additive interaction effects and deviations from these assumptions. We estimated the deviation from the additive model using the interaction contrast ratio (ICR).8 An ICR of 0 denotes an additive interaction, and 0.5 or greater would be considered to be greater than additive. With a lower 95% CI ⬎0.5, we would conclude that the interaction is more than additive. RESULTS Between July 1998 and July 2006, we recruited 339 cases of angiogram-confirmed aSAH. All but one case was matched to three controls; the remaining case had two control matches. Thus, there

Table 2

Conditional logistic regression results for additive interaction model of family history of intracranial aneurysm and smoking history Cases Controls (n ⴝ 335) (n ⴝ 1,016) Unadjusted OR Adjusted OR*

Family history and current smoking

25

16

8.9 (4.5–17.6)

6.4 (3.1–13.2)

Family history and former smoking

5

10

2.3 (0.7–7.2)

1.8 (0.5–6.4)

Family history, no smoking

7

16

2.6 (1.0–7.2)

2.5 (0.9–6.9)

No family history, current smoking

185

280

3.9 (2.8–5.5)

3.1 (2.2–4.4)

No family history, former smoking

48

298

0.9 (0.6–1.4)

0.8 (0.5–1.3)

Neither family history nor smoking

65

392

Reference

Reference

Family history refers to family history of intracranial aneurysm/subarachnoid hemorrhage. *Adjusting for history of diabetes, history of hypertension, frequent alcohol use, education, and body mass index. OR ⫽ odds ratio.

were a total of 1,016 controls. Table 1 presents the demographic data for the cases and controls. Because controls were matched to cases on a case-by-case basis, there were no significant differences in the average age, percent female, or percent black between cases and controls. Table 2 presents the results for the analysis of factors representing the family history by smoking additive interaction. Both current smoking (p ⬍ 0.0001) and a family history of brain aneurysm/SAH (p ⫽ 0.03) were independently associated with aSAH. However, having both aSAH and a family history of SAH was associated with a markedly increased risk of aSAH (odds ratio ⫽ 6.4, p ⬍ 0.0001) after adjustment for risk factors. These latter comparisons were made using the absence of current smoking and a family history of SAH as the referent group. We examined the models of both multiplicative and additive interactions. A formal test for a multiplicative interaction was not significant (p ⫽ 0.80). We then examined for deviation from the additive model using the ICR. The ICR was 2.19 with a 95% CI of 0.80 to 5.99. The lower bound of 0.80, being ⬎0.50, suggests departure from the additive model. These models were adjusted for hypertension, diabetes, frequent alcohol use, body mass index, and education level. We report evidence of an interaction between current smoking and the familial aggregation of IA/SAH. We were unable to find a similar association with former smoking and family history of IA/SAH, which suggests that the risk conferred by an interaction may be lowered by quitting smoking. This finding has relevance for both clinical management as well as investigation of the genetic epidemiology of aSAH. Clinicians should assess family history and smoking exposure to quantify and decrease risk to family members of a patient with aSAH. An understanding of the interaction between DISCUSSION

smoking exposure and family history of aSAH is necessary to enable future genetic research that will allow us to best understand the biology of aneurysm formation and rupture. Clinically, family members of persons with aSAH should be advised of the markedly increased risk for aSAH with the combination of family history and smoking exposure. While all smokers should be advised to quit smoking, recent evidence suggests that a lifealtering event, specifically aSAH, has a significant impact on the behavior of smoking9 and may also be used in counseling family members about the importance of not initiating smoking behavior. Information from the current study may help to increase the potential for quitting prior to life-threatening aSAH, which is fatal in 35– 40% of patients.10 Our data also emphasize the importance of screening family members with a family history of aSAH who smoke. Our results are congruent with the recent findings from the Familial Intracranial Aneurysm Study, which reported identifying intracranial aneurysms in 20% of family members without a known history of IA when screened only if they had a history of smoking or hypertension.11 This high rate of detection suggests that the use of risk factors may increase the yield of identifying unruptured intracranial aneurysms in relatives of cases. Almost all linkage studies for IA reported thus far did not include smoking behavior.12-16 If a gene– environment interaction exists, it is possible that without analyzing this critical trait a potential factor may have been missed. The Familial Intracranial Aneurysm Study recently reported that three of four chromosomal regions with possible linkage to IA appeared to have greater effect in those families with the heaviest smoking.11 A multiplicative interaction (the risk for a disease in those with both risk factors is equal to or greater than the multiplied risk ratios of each risk factor alone) is the most parsimonious determination of interaction. Restriction to accepting only this type of interaction would eliminate the possibility of identifying non-multiplicative interactions (e.g., the observed risk for a disease in those with both risk factors is greater than adding the individual risk ratios of each risk factor separately).17,18 Our findings suggest that we cannot reject a multiplicative interaction (one may still exist). The use of the ICR test is inappropriate for diseases that are not rare (⬎5%). However, the test is appropriate for this phenotype given the low prevalence (1% prevalence of IA). One explanation for a non-multiplicative interaction is that the same risk factor does not exist consistently across all families and thus, a purely multiplicative interaction is unlikely to be identified. Neurology 72

January 6, 2009

71

Intracranial aneurysm is likely a complex polygenic trait, and thus, different genetic factors may have different degrees of interaction with risk factors (smoking and otherwise) that influence the result. Familial aggregation of a particular phenotype does not necessarily indicate a genetic factor has led to that familial aggregation. Many nongenetic factors such as behavioral or cultural aggregation of risk factors may explain a familial aggregation of a phenotype. However, we have included the major known risk factors for aSAH and have found that the association of a positive family history was independent of their presence, which suggests this would have a limited impact on the finding. A reporting bias may also occur among patients with IA/SAH compared to controls wherein cases are more likely to report a positive family history. However, we would anticipate that the reporting rate would be similar between subjects with and without smoking. Therefore the possibilities are that the finding is spurious (requires confirmation), is associated with some nongenetic familial factor that has not been controlled for, or that provides evidence of a gene– environment interaction. Received April 7, 2008. Accepted in final form September 23, 2008. REFERENCES 1. Kissela BM, Sauerbeck L, Woo D, et al. Subarachnoid hemorrhage: a preventable disease with a heritable component. Stroke 2002;33:1321–1326. 2. Broderick JP, Viscoli CM, Brott T, et al. Major risk factors for aneurysmal subarachnoid hemorrhage in the young are modifiable. Stroke 2003;34:1375–1381. 3. Nakagawa T, Hashi K, Kurokawa Y, Yamamura A. Family history of subarachnoid hemorrhage and the incidence of asymptomatic, unruptured cerebral aneurysms. J Neurosurg 1999;91:391–395. 4. Kubota M, Yamaura A, Ono J. Prevalence of risk factors for aneurysmal subarachnoid haemorrhage: results of a Japanese multicentre case control study for stroke. Br J Neurosurg 2001;15:474–478. 5. Woo D, Sauerbeck LR, Kissela BM, et al. Genetic and environmental risk factors for intracerebral hemorrhage:

72

Neurology 72

January 6, 2009

6.

7.

8. 9.

10.

11.

12.

13.

14.

15.

16.

17.

18.

preliminary results of a population-based study. Stroke 2002;33:1190–1195. Woo D, Sekar P, Chakraborty R, et al. Genetic epidemiology of intracerebral hemorrhage. J Stroke Cerebrovasc Dis 2005;14:239–243. Botto LD, Khoury MJ. Commentary: facing the challenge of gene-environment interaction: the two-by-four table and beyond. Am J Epidemiol 2001;153:1016–1020. Rothman KJ, Grenland S. Modern Epidemiology. Philadelphia, PA: Lippincott Williams & Wilkins; 1998. Sauerbeck LR, Khoury JC, Woo D, Kissela BM, Moomaw CJ, Broderick JP. Smoking cessation after stroke: education and its effect on behavior. J Neurosci Nurs 2005;37: 316–319, 325. Hop JW, Rinkel GJ, Algra A, van Gijn J. Case-fatality rates and functional outcome after subarachnoid hemorrhage: a systematic review. Stroke 1997;28:660–664. Foroud T, Koller D, Lai D, et al. Genome-wide SNP linkage screen for intracranial aneurysm susceptibility genes. Stroke 2007;38:455. Abstract. Nahed BV, Seker A, Guclu B, et al. Mapping a Mendelian form of intracranial aneurysm to 1p34.3-p36.13. Am J Hum Genet 2005;76:172–179. Mineharu Y, Inoue K, Inoue S, et al. Model-based linkage analyses confirm chromosome 19q13.3 as a susceptibility locus for intracranial aneurysm. Stroke 2007;38:1174– 1178. Ozturk AK, Nahed BV, Bydon M, et al. Molecular genetic analysis of two large kindreds with intracranial aneurysms demonstrates linkage to 11q24-25 and 14q23-31. Stroke 2006;37:1021–1027. Roos YB, Pals G, Struycken PM, et al. Genome-wide linkage in a large Dutch consanguineous family maps a locus for intracranial aneurysms to chromosome 2p13. Stroke 2004;35:2276–2281. Verlaan DJ, Dube MP, St-Onge J, et al. A new locus for autosomal dominant intracranial aneurysm, ANIB4, maps to chromosome 5p152-143. J Med Genet 2006; 43:e31. Khoury MJ, Adams Jr. MJ, Flanders WD. An epidemiologic approach to ecogenetics. Am J Hum Genet 1988;42: 89–95. Moore JH, Williams SM. Traversing the conceptual divide between biological and statistical epistasis: systems biology and a more modern synthesis. Bioessays 2005;27:637– 646.

Oral fingolimod (FTY720) in multiple sclerosis Two-year results of a phase II extension study

P. O’Connor, MD G. Comi, MD X. Montalban, MD J. Antel, MD E.W. Radue, MD A. de Vera, MD H. Pohlmann, MSc L. Kappos, MD For the FTY720 D2201 Study Group*

Address correspondence and reprint requests to Dr. Paul O’Connor, St. Michael’s Hospital, Toronto, ON, Canada [email protected]

ABSTRACT

Objective: To report the results of a 24-month extension of a phase II trial assessing the efficacy, safety, and tolerability of the once-daily oral sphingosine-1-phosphate receptor modulator, fingolimod (FTY720), in relapsing multiple sclerosis (MS).

Methods: In the randomized, double-blind, placebo-controlled core study, 281 patients received placebo or FTY720, 1.25 or 5.0 mg/day, for 6 months. During the subsequent dose-blinded extension, patients assigned to placebo were re-randomized to either dose of FTY720; those originally assigned to FTY720 continued at the same dose. Patients receiving FTY720 5.0 mg were switched to 1.25 mg during the month 15 to month 24 study visits. Results: Of 281 patients randomized in the core study, 250 (89%) entered the extension phase, and 189 (75.6%) received treatment for 24 months. During the core study, FTY720 significantly reduced gadolinium-enhanced (Gd⫹) lesions and annualized relapse rate (ARR) compared with placebo, with no differences between doses. During the extension phase, patients who switched from placebo to FTY720 showed clear reductions in ARR and lesion counts compared with the placebo phase; ARR and lesion counts remained low in patients who continued FTY720 treatment. After 24 months, 79 to 91% of patients were free from Gd⫹ lesions and up to 77% of patients remained relapse free. FTY720 was well tolerated; no new safety concerns emerged during months 7 to 24 compared with the 6-month core study.

Conclusions: Once-daily oral treatment with FTY720, 1.25 or 5.0 mg, for up to 2 years, was well tolerated and was associated with low relapse rates and lesion activity. Neurology® 2009;72:73–79 GLOSSARY AE ⴝ adverse event; ALT ⴝ alanine aminotransferase; ARR ⴝ annualized relapse rate; BP ⴝ blood pressure; DLCO ⴝ carbon monoxide diffusion capacity; EDSS ⴝ Expanded Disability Status Scale; FEV1 ⴝ forced expiratory volume in 1 second; FVC ⴝ forced vital capacity; Gdⴙⴝ adolinium-enhanced; MoA ⴝ mechanism of action; MS ⴝ multiple sclerosis; MSFC ⴝ Multiple Sclerosis Functional Composite; SAE ⴝ serious adverse event; ULN ⴝ upper limit of normal.

Current first-line disease-modifying therapies for multiple sclerosis (MS)—interferon-␤ and glatiramer acetate— have modest efficacy, reducing relapse rates by approximately 30% and marginally affecting disability progression.1 Frequent parenteral administration is inconvenient, and interferon-related flu-like reactions can impair quality of life and treatment adherence.2 Natalizumab, an ␣4 integrin antagonist, has demonstrated better efficacy than first-line therapies,3 but is administered by monthly infusion. An effective, well-tolerated, orally active treatment for MS is needed.4 Oral fingolimod (FTY720; Novartis Pharma, Basel, Switzerland) is a sphingosine-1phosphate receptor modulator in phase III development for the treatment of MS. FTY720 undergoes phosphorylation5 and binds to sphingosine-1-phosphate type 1 receptors6,7 on lymphocytes. This induces receptor internalization, depriving cells of the mechanism to sense the Supplemental data at www.neurology.org *Members of the FTY720 D2201 Study Group are listed in the appendix. From St. Michael’s Hospital (P.O.), Toronto, ON, Canada; Ospedale San Raffaele (G.C.), Milan, Italy; University Hospital Edif. EUI (X.M.), Barcelona, Spain; Montreal Neurological Institute (J.A.), Montreal, QC, Canada; MS MRI Evaluation Centre (E.W.R.) and Neurology and Department of Biomedicine (L.K.), University Hospital, Basel; and Novartis Pharma AG (A.d.V., H.P.), Basel, Switzerland. Supported by Novartis Pharma AG, Basel, Switzerland. Disclosure: Author disclosures are provided at the end of the article. Copyright © 2009 by AAN Enterprises, Inc.

73

stimulus to egress from lymphoid tissue; hence, lymphocytes are retained.8 In rodents with experimental autoimmune encephalomyelitis, FTY720 prevents disease development following immunization with myelin antigens and reverses established neurologic deficits.9-11 We report the 24-month efficacy, safety, and tolerability results of a phase II proof-ofconcept study extension of FTY720 for relapsing MS.12 METHODS This randomized, double-blind, placebocontrolled study with active-drug extension was performed at 32 centers in 11 countries in Europe and Canada from May 2003 to April 2006. The protocol was approved by review boards at participating centers, and the study was conducted per the principles of the Declaration of Helsinki and the International Conference on Harmonisation Guidelines for Good Clinical Practice. Trial registration: NCT0023540.

Study design. The study design and inclusion/exclusion criteria have been published.12 Briefly, patients aged 18 to 60 years with relapsing MS13 (relapsing-remitting or secondary progressive) with at least one relapse during the previous year or at least two relapses during the previous 2 years, or at least one gadolinium-enhanced (Gd⫹) lesion on MRI, and an Expanded Disability Status Scale (EDSS)14 score of 0 to 6 were randomized to placebo or once-daily oral FTY720 (1.25 or 5.0 mg) for 6 months (core study). On core study completion, patients could enter a doseblinded extension. Placebo recipients were re-randomized to one of the FTY720 doses; those already receiving FTY720 continued at the same dose. Initial treatment allocations were not revealed to patients or site personnel. During the month 15 to 24 study visits, patients receiving FTY720 5.0 mg were switched to 1.25 mg because a benefit-risk assessment indicated that the higher dose offered no efficacy advantage and possibly a less favorable safety profile. Because some patients received 5.0 mg for almost 24 months before switching, results for patients initiating FTY720 1.25 or 5.0 mg are presented separately.

Assessments. Extension study visits occurred at 3-month intervals. Efficacy assessments included MS relapses, EDSS score, and Multiple Sclerosis Functional Composite (MSFC) score.15 EDSS was measured at scheduled visits and after relapses, by certified16 independent neurologists who were not involved in treatment, were blinded to treatment allocation, and had no access to patient medical records. “Confirmed relapse” was defined as the occurrence of new symptoms (or worsening of previously stable/ improving symptoms) and signs not associated with fever, lasting ⬎24 hours, occurring after ⱖ14 days’ stability or improvement, and accompanied by an increase of ⱖ0.5 points in overall EDSS score or 1 point for at least one functional system (excluding bowel, bladder, and mental functional systems). “Confirmed disability progression” was defined as an increase of ⱖ1 EDSS point from core study baseline (or 0.5 points if baseline score was ⱖ5.5) at any visit during the first 24 months and confirmed in a scheduled visit 3 months later. MRI assessments were performed at core baseline, months 1, 2, 3, 4, 5, 6, and 12, and annually thereafter; a protocol amendment permitted another evaluation at month 18. Spin-echo T174

Neurology 72

January 6, 2009

weighted images before and 10 minutes after injection of a double dose (0.2 mmol/kg) of gadopentetate dimeglumine, as well as dual fast spin-echo proton density/T2-weighted images, were acquired in 1.5 T scans. All scans were evaluated by blinded raters at the MS MRI Evaluation Centre in Basel. Measures of inflammatory activity (Gd⫹ lesions, new T2 lesions), T2 burden of disease, and change in brain volume from baseline (data not shown) were evaluated. Adverse events (AEs) were recorded by the treating physician at each visit. The 3-month laboratory evaluation (hematology, clinical chemistry, urinalysis) was assessed centrally. Pulmonary function testing, including forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and carbon monoxide diffusion capacity (DLCO), was performed every 6 months. This testing was introduced in a late protocol amendment; pretreatment values are available only for a subset of patients. Because FTY720 induces a transient pulse rate decrease after initial administration,17 patients entering the core study underwent pulse rate monitoring for 6 hours after initiating treatment. In renal transplant recipients, macular edema was reported in 1.3% to 2.2% of patients receiving FTY720 plus cyclosporine, but not in patients receiving mycophenolate mofetil plus cyclosporine.18 This observation was made during the present study and consequently all patients in the extension underwent ophthalmologic examination including visual acuity testing, ophthalmoscopy, and optic coherence tomography or fluorescein angiography (or both).

Statistical methods. For this extension-phase analysis, efficacy was assessed in the intent-to-treat population (all randomized patients who received at least one dose of FTY720 during the core or extension; n ⫽ 271). AEs are presented for patients who received at least one dose of FTY720 during the extension (extension population, n ⫽ 250). Efficacy and safety were assessed in patients receiving FTY720 1.25 mg throughout the core and extension (FTY720 1.25 mg), FTY720 5.0 mg throughout the core and extension (FTY720 5.0 mg), patients switched from placebo to FTY720 1.25 mg for the extension (placebo-FTY720 1.25 mg), and patients switched from placebo to FTY720 5.0 mg (placeboFTY720 5.0 mg). Annualized relapse rate (ARR) in each group was calculated as the total number of confirmed relapses per treatment group/total time in study interval per treatment group ⫻ 365.25. Probability of first-confirmed relapse was calculated by the Kaplan-Meier method, and proportions of relapse-free patients at month 24 were calculated from the Kaplan-Meier estimations. All available MRI scans collected up to the month 24 visit were included in analyses. All extension-phase analyses used observed data only; missing data were not imputed. Between-group differences in the number of Gd⫹ lesions or new T2 lesions were assessed in post hoc analyses using the Wilcoxon rank sum test. Between-group differences in the proportions of patients free from Gd⫹ lesions or new T2 lesions were assessed in post hoc analyses using the ␹2 test. Other extension phase analyses are presented as descriptive statistics without inferential significance testing.

Of the 250 patients who entered the extension, 189 (75.6%) completed to month 24 (figure 1). The most common reasons for treatment discontinuation in the extension, across groups, were AEs (10.4%) and withdrawal of consent (8.8%; figure 1). Demographic characteristics and disease history of pa-

RESULTS

Figure 1

Patient disposition

Note that number of discontinued interventions and completers of the core phase are based on the core intent-to-treat (ITT) population.

tients entering the extension were generally similar to the randomized population of the core study (table 1).12 Efficacy. MRI outcomes. In patients switched from pla-

cebo to FTY720 at the start of the extension, levels of inflammatory activity after the first 6 months of FTY720 treatment (table e-1 on the Neurology® Web site at www.neurology.org) were consistent with those of FTY720-treated patients during the core study, where FTY720 1.25 and 5.0 mg significantly reduced the number of Gd⫹ lesions relative to placebo (p ⬍ 0.001).12 At month 24, this pattern was sustained; the majority of patients in all groups were

free from Gd⫹ lesions (79 to 91%) or new T2 lesions (66 to 74%), showing little change from month 12 values, with the exception of 18% more Gd⫹ lesionfree patients in the placebo-FTY720 5.0 mg group. Median T2 lesion volume was reduced in all groups. However, as the range of T2 lesion volumes was large in all groups and the differences in T2-volume change were relatively small, interpretation of these data is precluded. Both doses of FTY720 had a similar impact on MRI outcomes during the core and extension studies (table e-1). There were no significant differences beNeurology 72

January 6, 2009

75

Table 1

Baseline demographic characteristics and disease history of patients entering the extension (extension population) FTY720 1.25 mg (n ⴝ 87)

FTY720 5 mg* (n ⴝ 80)

Placebo-FTY720 Placebo-FTY720 1.25 mg 5.0 mg* (n ⴝ 40) (n ⴝ 43)

Mean

37.5

37.2

35.9

38.6

Range

19–60

18–59

19–56

22–56

21 (24)

25 (31)

14 (35)

15 (35)

Age, y

Male, n (%) Duration of disease, y Mean ⴞ SD

8.3 ⫾ 7.3

Median (range)

8.4 ⫾ 8.2

8.7 ⫾ 6.7

8.1 ⫾ 6.1

6.9 (0.3–50.2) 6.5 (0.5–42.2) 7.0 (0.5–28.8)

6.9 (0.2–26.6)

79 (91)

70 (88)

36 (90)

40 (93)

8 (9)

10 (13)

4 (10)

Course of disease Relapsing-remitting, n (%) Secondary progressive, n (%)

3 (7)

EDSS score Mean ⴞ SD

2.54 ⫾ 1.3

2.48 ⫾ 1.3

2.40 ⫾ 1.4

2.57 ⫾ 1.3

Median (range)

2.0 (0.0–6.0)

2.0 (0.0–6.0)

2.0 (0.0–6.0)

2.0 (0.0–6.0)

*Initial dose of FTY720; during months 15 to 24 all patients in these two groups were switched to the lower 1.25 mg dose of FTY720. EDSS ⫽ Expanded Disability Status Scale.

tween patients treated continuously with FTY720 1.25 or 5.0 mg for number of Gd⫹ or new T2 lesions, or for the proportion of patients who were free from Gd⫹ lesions or new T2 lesions at month 6, 12, or 24 (p ⬎ 0.05 for all comparisons). For each treatment group, all MRI outcome measures improved or remained stable following reduction of FTY720 dose Figure 2

Kaplan-Meier plot of time to first confirmed relapse (intent-to-treat population)

from 5.0 to 1.25 mg from month 15 onwards. In patients who started treatment with FTY720 5.0 mg, comparison of the means/medians of MRI outcome measures at month 12 (after patients had received FTY720 5.0 mg for 6 to 12 months) with those at month 24 (all patients had switched to FTY720 1.25 mg between months 15 and 24) provided no indication that lowering the dose was associated with a reduction in efficacy (table e-1). The number of Gd⫹ lesions remained stable at 0.2 at both months 12 and 24 in the continuous-FTY720 5.0 mg group and was reduced from 0.3 at month 12 to 0.2 at month 24 in the placebo-FTY720 5.0 mg group (table e-1). Clinical outcomes. ARR at month 6 was significantly lower in patients assigned to FTY720 at core baseline than in placebo recipients (relative reduction: 55% for FTY720 1.25 mg and 53% for FTY720 5.0 mg; p ⱕ 0.01 for both comparisons)12 and remained low during the extension (ARR: 0.14 to 0.17; table e-1). In placebo-FTY720 patients, ARR decreased markedly during the first 6 months of the extension (0.70 for FTY720 1.25 mg and 0.69 for 5.0 mg for months 0 to 6 vs 0.21 for 1.25 mg and 0.10 for 5.0 mg for months 7 to 12), and was low throughout the extension (ARR for months 7 to 24: 0.12 to 0.26; table e-1). At month 24, most patients in the continuous-FTY720 groups (75 to 77%) were relapse-free (figure 2). As reported previously, EDSS scores at month 12 were similar across groups.12 At month 24, mean EDSS scores remained stable in all groups. The proportions of patients with 3-month confirmed disability progression at any time during the extension were similar among groups: 17.1% for FTY720 1.25 mg, 24.7% for FTY720 5.0 mg, 18.9% for placeboFTY720 1.25 mg, and 25.6% for placebo-FTY720 5.0 mg. In line with EDSS findings, MSFC scores showed negligible fluctuation throughout the extension (data not shown). Safety and tolerability. During the extension, most

*A confirmed relapse was defined as the occurrence of new symptoms (or worsening of previously stable or improving symptoms) and signs not associated with fever, lasting more than 24 hours, occurring after ⱖ14 days’ stability or improvement, and accompanied by an increase of ⱖ0.5 points in the EDSS score or 1 point in the score for at least one functional system (excluding the bowel, bladder, and mental functional systems). 76

Neurology 72

January 6, 2009

AEs, including serious AEs (SAEs), were more common in the FTY720 5.0-mg groups than in the FTY720 1.25-mg groups (table 2). Most AEs were mild or moderate in intensity. The AE profile in placebo-FTY720 groups was similar to that in continuous-FTY720 groups. The most common AEs (ⱖ10% of patients in any group) during the extension were nasopharyngitis, headache, influenza, and lymphopenia. The only AE that led to permanent treatment discontinuation in more than one patient in any group was lymphopenia (two patients in each continuous-FTY720 group). During the extension, SAEs were reported in 26 patients (10%), with the highest incidence in the continuous-FTY720 5.0 mg groups (table 2). With

Table 2

Incidence of most commonly reported AEs (>10% of patients in any group) during months 7 to 24 (extension population)

At least one AE

FTY720 1.25 mg (n ⴝ 87)

FTY720 5 mg (n ⴝ 80)

Placebo-FTY720 1.25 mg (n ⴝ 40)

Placebo-FTY720 5.0 mg (n ⴝ 43)

35 (87.5)

39 (90.7)

2 (5.0)

4 (9.3)

77 (88.5)

76 (95.0)

Discontinuations due to AEs

9 (10.3)

9 (11.3)

Any SAE

7 (8.0)

12 (15.0)

2 (5.0)

5 (11.6)

Any severe AE

9 (10.3)

11 (13.8)

5 (12.5)

6 (14.0)

Nasopharyngitis

17 (19.5)

21 (26.3)

5 (12.5)

8 (18.6)

Headache

13 (14.9)

9 (11.3)

7 (17.5)

8 (18.6)

Influenza

8 (9.2)

13 (16.3)

7 (17.5)

4 (9.3)

10 (11.5)

12 (15.0)

4 (10.0)

4 (9.3)

8 (9.2)

3 (3.8)

6 (15.0)

8 (18.6)

AEs

Lymphopenia Fatigue Leukopenia

10 (11.5)

11 (13.8)

1 (2.5)

3 (7.0)

ALT increased

5 (5.7)

4 (5.0)

5 (12.5)

6 (14.0)

Back pain

5 (5.7)

3 (3.8)

4 (10.0)

5 (11.6)

Hypertension

9 (10.3)

4 (5.0)

2 (5.0)

2 (4.7)

Upper respiratory tract infection

4 (4.6)

9 (11.3)

0 (0)

4 (9.3)

Depression

5 (5.7)

3 (3.8)

0 (0)

5 (11.6)

Migraine

3 (3.4)

2 (2.5)

4 (10.0)

3 (7.0)

All values are n (%). AE ⫽ adverse event; ALT ⫽ alanine aminotransferase; SAE ⫽ serious adverse event.

the exception of asthma (reported in two patients receiving FTY720 5.0 mg), no SAEs occurred in more than one patient. In the placebo-FTY720 1.25 mg group, arrhythmia, bradycardia, palpitations, enterocolitis, dengue fever, and abnormal heart rate were reported during the extension. In the placeboFTY720 5.0 mg group, abdominal pain, nausea, herpes zoster, otitis externa, joint dislocation, bronchospasm, and varicose ulceration were reported. Unconfirmed macular edema, peripheral edema, hepatitis, jaundice, MS relapse, hirsutism, and flushing were reported as SAEs in the continuous-FTY720 1.25 mg group. In the continuous-FTY720 5.0 mg group, neutropenia, adrenal mass, unconfirmed macular edema, acute abdomen, inguinal hernia, salpingitis, drug exposure during pregnancy, dizziness, syncope, pregnancy, and hypertension were reported as SAEs. During the core study (months 0 to 6), one basal cell and one squamous cell carcinoma were reported in the FTY720 5.0-mg group; the patient with basal cell carcinoma had a history of multiple skin lesions. During the extension (months 7 to 24), one case of basal cell carcinoma (preexisting before study start) was reported in the placebo-FTY720 5.0 mg group. All skin lesions were successfully excised. Asymptomatic liver enzyme elevations, predominantly alanine aminotransferase (ALT), were observed during FTY720 treatment. Over 24 months,

ALT elevations exceeding three times the upper limit of normal (3 ⫻ ULN) occurred in 15% of the placebo-FTY720 1.25 mg group, 12% of the placebo-FTY720 5.0 mg group, 16% of the FTY720 1.25 mg group, and 15% of the FTY720 5.0 mg group. Similar to the core study,12 elevated ALT was reversed on discontinuation of FTY720 in all patients with follow-up. In all instances, concomitant elevations of liver enzymes and total bilirubin remained below the threshold indicative of substantial hepatocellular injury (ALT above 3 ⫻ ULN; total bilirubin above 2 ⫻ ULN). Mean arterial blood pressure (BP) decreased within the first hour after the first dose of FTY720 was administered and had decreased to 5 to 6 mm Hg below baseline at 4 to 5 hours postdose, but few patients had notable BP abnormalities during this period. Within the first 6 hours after treatment initiation, low systolic (ⱕ90 mm Hg)/diastolic (ⱕ45 mm Hg) BPs were observed in 11%/5% of patients treated with FTY720 1.25 mg, 15%/9% of those treated with FTY720 5.0 mg, and 9%/4% of those receiving placebo. On day 7, BP had returned to baseline values. After 2 months of treatment, BP elevation to 4 to 6 mm Hg above baseline was observed, but with no further increase through month 24. At month 24, the mean increase in sitting BP from core baseline was 4.1 to 6.3 mm Hg across groups. In the extension, hypertension was reported as an AE in 5 to 10% of patients (table 2). As expected from the mechanism of action (MoA) of FTY720,17 circulating lymphocytes decreased up to 75% compared with baseline values, reaching a mean of approximately 500 to 600 cells/mm3 within hours of initial treatment, but did not decrease further with continued treatment. At month 24, lymphocyte counts ⬍150/mm3 were more common among patients receiving FTY720 5.0 mg than 1.25 mg (17% vs 7%); one patient receiving FTY720 5.0 mg presented a lymphocyte count ⬍100/mm3 at one visit. Consistent with the core study results and with the MoA of FTY720,12,19,20 patients who switched to FTY720 treatment at month 6 had a reduction in pulse rate that was apparent ⱕ1 hour after the first dose and was maximal after 4 to 5 hours, attenuating thereafter. One patient who switched from placebo to FTY720 reported symptoms of bradycardia (cold sensations), which resolved without intervention. At month 24, pulse rate was similar to pretreatment levels across groups (data not shown). At core study completion, pulmonary function tests showed a reduction in FEV1 in patients who received FTY720 5.0 mg compared with placebo recipients (p ⫽ 0.003).12 FEV1 was not significantly Neurology 72

January 6, 2009

77

different between patients who received FTY720 1.25 mg and placebo recipients. No clinically relevant changes in FVC or DLCO were seen. During the extension, dyspnea or asthma were reported more frequently with FTY720 5.0 mg (seven patients in the continuous FTY720 5.0 mg group, three in the placebo-FTY720 5.0 mg group) than FTY720 1.25 mg (one patient in each group reported one event of mild dyspnea, which resolved without treatment). Ophthalmic examinations revealed no confirmed case of macular edema in patients receiving FTY720 for up to 24 months; reports of macular edema as AEs or SAEs were reviewed centrally by retinal experts, and a diagnosis of macular edema was not confirmed in any patient. The 6-month, placebo-controlled core study demonstrated that once-daily oral treatment with FTY720 provides significant and rapid improvements in MRI measures of inflammation and relapse-related clinical endpoints in patients with relapsing MS.12 This extension study indicates that patients treated with FTY720 for 24 months continue to exhibit low levels of disease activity, as demonstrated by the high proportion (⬎70%) remaining free from clinical relapses, the low ARR during months 7 to 24, and the low levels of inflammatory activity on MRI. Similarly, patients who switched from placebo to FTY720 had marked improvements in clinical and MRI outcomes, corroborating results of the core study. Furthermore, use of a double dose of gadolinium as an MRI contrast agent improves the detection of enhancing lesions compared with the standard single dose,21 so the proportion of patients free from Gd⫹ lesions at month 24 following FTY720 treatment (79 to 91%) is likely to be a conservative estimate. The study was not powered to evaluate clinical endpoints. However, the proportion of patients with 3-month confirmed disability progression was low (17 to 26%). The absence of a control group in the extension, the use of open-label treatment, and the possible confounding effect of dropouts preclude firm conclusions about the true long-term efficacy of FTY720. Also, because only data up to the discontinuation of treatment are analyzed, there is a potential for censoring bias of efficacy and safety data. Nevertheless, the low incidence of relapses and MRI inflammatory lesions is encouraging and suggests that the treatment effects of FTY720 in relapsing MS are sustained. FTY720 treatment was well tolerated for up to 24 months; the AE profile during the extension was similar to that in the core study.12 As in the core study, DISCUSSION

78

Neurology 72

January 6, 2009

AEs occurred more frequently with FTY720 5.0 mg than with 1.25 mg; nonserious infections were the most common AEs. Although headache was reported frequently in all groups throughout the study, no clear association with FTY720 was observed. Some AEs, such as dyspnea (more common with 5.0 than 1.25 mg FTY720), gastrointestinal disorders, and somnolence, were reported following treatment initiation in the core study, but the incidences of these events decreased with time on treatment and were less common during the extension. SAEs were also reported more frequently in the FTY720 5.0 mg groups; the majority were reported in no more than one patient. The pharmacodynamic effects observed during FTY720 treatment included effects on FEV1, pulse rate, and BP. These effects were either transient or stable up to 24 months. The large phase III program will further characterize the safety and tolerability profile of FTY720 and increase our understanding of this promising new oral treatment for relapsing MS. ACKNOWLEDGMENT The authors thank Oxford PharmaGenesis Ltd. for assistance in collating the comments of authors and other named contributors and editing the article for submission.

DISCLOSURE This study was sponsored by Novartis Pharma AG, Basel, Switzerland. P. O’Connor and J. Antel report having received honoraria (⬎$10,000) from Novartis Pharmaceuticals Corporation during the course of the study. P. O’Connor and L. Kappos report having received grants (⬎$10,000) from Novartis Pharmaceuticals Corporation, East Hanover, NJ, for other research activities not reported in this article. G. Comi reports having received honoraria (⬍$10,000) from Novartis Pharmaceuticals Corporation during the course of the study and has given expert testimony related to the subject of this article (⬍$10,000). A. de Vera has equity interests ⬍$10,000, and H. Pohlmann has equity interests ⬎$10,000; both are current employees of Novartis Pharma AG, Basel, Switzerland. X. Montalban and E.W. Radue report no conflicts of interest.

APPENDIX The following people participated in the study (names of principal investigators are in boldface type). Data and Safety Monitoring Board: J.D. Easton (Chair), RI Hospital-Brown Medical School, Providence, RI; J. Kesselring, Chefarzt Neurologie Rehabilitationszentrum, Valens, Switzerland; B.G. Weinshenker, Mayo Clinic College of Medicine, Rochester, MN; A. Laupacis, Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Canada; M. Zarbin, Institute of Ophthalmology and Visual Sciences, UMDNJ Medical School/Ophthalmology, Newark, NJ; T. Calandra, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; N. Temkin, University of Washington, Redmond, WA; J. DiMarco, University VA Health System-Cardiology, Charlottesville, VA; L.D. Hudson, University of Washington, Seattle, WA. Steering Committee: L. Kappos (Chair), University Hospital, Basel, Switzerland; J. Antel, Le Centre Universitaire de Sante´ McGill, Montreal Neurological Institute, McGill University, Montreal, Canada; G. Comi, San Raffaele Hospital, Milan, Italy; X. Montalban, Hospital Vall d’Hebron, Barcelona, Spain; P. O’Connor, St. Michael’s Hospital, Toronto, Canada; E.W. Radue, University Hospital, Basel, Switzerland. Study Group—Canada: J. Antel, L. Durcan, A. Bar Or, Le Centre Universitaire de Sante´ McGill, Montreal Neurological Institute, McGill University, Montreal; P. Duquette, G. Bernier, Centre Hospitalier Universitaire-Notre-Dame Hospital, Montreal;

M. Freedman, H. MacLean, F. Costello, Ottawa Hospital, Ottawa; P. O’Connor, T.A. Gray, M. Hohol, St Michael’s Hospital, Toronto; V. Devonshire, S. Hashimoto, UBC Hospital, Vancouver. Denmark: P.S.G. Sørensen, P. Datta, J.C. Faber-Rod, Neurocentert, Rigshospitalet, Copenhagen; J. Frederiksen, S. Knudsen, V. Petrenaite, Kobenhavns Amts Sygehus, Glostrup. Finland: H. Harno, M. Fa¨rkkila, J. Halavaara, Postitalon La¨a¨ka¨riasema Oy, Helsinki; I. Elovaara, H. Kuusisto, J. Palmio, Finn-Medi Tutkimus Oy, Tampere; L. Airas, V. Kaasinen, M. Laaksonen, Turku University Hospital, Turku. France: P. Vermersch, Hoˆpital Roger Salengro, Lille; J. Pelletier, L. Feuillet, L. Suchet, Hoˆpital de la Timone, Marseille. Germany: E. Mauch, C. Gunser, K. Oberbeck, Akademisches KH der Universita¨t Ulm, Schwendi; P. Rieckmann, M. Buttmann, M. Klein, Julius-Maximilians-Universita¨t, Wu¨rzburg. Italy: A. Ghezzi, M. Zaffaroni, S. Baldini, Ospedale S. Antonio Abate, Gallarate; G. Mancardi, F. Cioli, E. Capello, Ospedale S. Martino Universita` degli Study di Genova, Genoa; G. Comi, M. Rodegher, M. Radaelli, San Raffaele Hospital, Milan; C. Pozzilli, E. Onesti, S. Romano, Ospedale Sant’Andrea Universita` La Sapienze, Rome. Poland: A. Czlonkowska, T. Litwin, L. Darda-Ledzion, Instytut Psychiatrii i Neurologii, Warsaw; H. Kwiecinski, M. Golebiowski, A. Podlecka, K. Nojszewska Klinika Neurologii AM, Warsaw, Portugal: L. Cunha, L. Sousa, F. Matias, Hospitais da Universidade de Coimbra, Coimbra; R. Pedrosa, M. Almeida, J. Esteves Pena, Hospital Sto. Anto´nio dos Capuchos, Lisbon; J. de Sa´, J. Ferreira, M. Rosa, Hospital de Santa Maria, Centro de Estudos Egas Moniz, Lisbon. Spain: T. Arbizu, O. Carmona, V. Casado, Ciutat Sanita`ria i Universita`ria de Bellvitge, Barcelona; X. Montalban, M. Tintore, R. Pelayo, Hospital Vall d’Hebron, Barcelona; R. Arroyo, M. Bartolome, V. De las Heras, Hospital Clinico San Carlos, Madrid; B. Casanova, I. Bosca, Hospital La Fe, Valencia; O. Fernandez, A. Leon, F. Romero, Hospital Carlos Haya, Malaga; G. Izquierdo, M. Gamero, J. Maria Garcia, Hospital Virgen de la Macarena, Seville. Switzerland: L. Kappos, J. Kuhle, M. Mehling, L. Achtnichts, University Hospital, Basel; N. Goebels, C. Skulina, J. Waskoenig, University Hospital, Zurich. United Kingdom: D. Bates, P. Nichols, Royal Victoria Infirmary, Newcastleupon-Tyne. MS-MRI Evaluation Center: University Hospital, Basel: E.W. Radue, K. Bendfeldt, Novartis Pharma, Basel, Switzerland; and East Hanover, NJ: G. Karlsson, P. Burtin, T. Zubal.

8.

9.

10.

11.

12.

13.

14.

15.

16. Received April 1, 2008. Accepted in final form September 24, 2008. REFERENCES 1. Goodin DS, Frohman EM, Garmany Jr. GP, et al. Disease modifying therapies in multiple sclerosis: report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology and the MS Council for Clinical Practice Guidelines. Neurology 2002; 58:169–178. 2. Calabresi PA. Considerations in the treatment of relapsing-remitting multiple sclerosis. Neurology 2002;58: S10–22. 3. Polman CH, O’Connor PW, Havrdova E, et al. A randomized, placebo-controlled trial of natalizumab for relapsing multiple sclerosis. N Engl J Med 2006;354:899–910. 4. Hafler DA. Multiple sclerosis. J Clin Invest 2004;113: 788–794. 5. Billich A, Bornancin F, Devay P, Mechtcheriakova D, Urtz N, Baumruker T. Phosphorylation of the immunomodulatory drug FTY720 by sphingosine kinases. J Biol Chem 2003;278:47408–47415. 6. Brinkmann V, Davis MD, Heise CE, et al. The immune modulator FTY720 targets sphingosine 1-phosphate receptors. J Biol Chem 2002;277:21453–21457. 7. Mandala S, Hajdu R, Bergstrom J, et al. Alteration of lymphocyte trafficking by sphingosine-1-phosphate receptor agonists. Science 2002;296:346–349.

17.

18.

19.

20.

21.

Brinkmann V, Cyster JG, Hla T. FTY720: sphingosine 1-phosphate receptor-1 in the control of lymphocyte egress and endothelial barrier function. Am J Transplant 2004;4: 1019–1025. Fujino M, Funeshima N, Kitazawa Y, et al. Amelioration of experimental autoimmune encephalomyelitis in Lewis rats by FTY720 treatment. J Pharmacol Exp Ther 2003; 305:70–77. Webb M, Tham CS, Lin FF, et al. Sphingosine 1-phosphate receptor agonists attenuate relapsingremitting experimental autoimmune encephalitis in SJL mice. J Neuroimmunol 2004;153:108–121. Rausch M, Hiestand P, Foster CA, Baumann DR, Cannet C, Rudin M. Predictability of FTY720 efficacy in experimental autoimmune encephalomyelitis by in vivo macrophage tracking: clinical implications for ultrasmall superparamagnetic iron oxide-enhanced magnetic resonance imaging. J Magn Reson Imaging 2004;20:16–24. Kappos L, Antel J, Comi G, et al. Oral fingolimod (FTY720) for relapsing multiple sclerosis. N Engl J Med 2006;355:1124–1140. McDonald WI, Compston A, Edan G, et al. Recommended diagnostic criteria for multiple sclerosis: guidelines from the International Panel on the diagnosis of multiple sclerosis. Ann Neurol 2001;50:121–127. Kurtzke JF. Rating neurologic impairment in multiple sclerosis: an expanded disability status scale (EDSS). Neurology 1983;33:1444–1452. Fischer JS, Rudick RA, Cutter GR, Reingold SC. The Multiple Sclerosis Functional Composite Measure (MSFC): an integrated approach to MS clinical outcome assessment. National MS Society Clinical Outcomes Assessment Task Force. Mult Scler 1999;5:244–250. Kappos L, Lechner-Scott J, Lienert C. Neurostatus training and documentation CD-ROM for a standardized neurological examination and assessment of Kurtzke’s functional systems and expanded disability status scale for MS patients. Basel, Switzerland: Point de Vue Audiovisuelle Produktionen, 2003. Available at: www.neurostatus. net/training/index.php. Accessed June 13, 2008. Schmouder R, Serra D, Wang Y, et al. FTY720: placebocontrolled study of the effect on cardiac rate and rhythm in healthy subjects. J Clin Pharmacol 2006;46:895–904. Salvadori M, Budde K, Charpentier B, et al. FTY720 versus MMP with cyclosporine in de novo renal transplantation: a 1-year, randomized controlled trial in Europe and Australasia. Am J Transplant 2006;6:2912–2921. Koyrakh L, Roman MI, Brinkmann V, Wickman K. The heart rate decrease caused by acute FTY720 administration is mediated by the G protein-gated potassium channel I. Am J Transplant 2005;5:529–536. Sanna MG, Liao J, Jo E, et al. Sphingosine 1-phosphate (S1P) receptor subtypes S1P1 and S1P3, respectively, regulate lymphocyte recirculation and heart rate. J Biol Chem 2004;279:13839–13848. Uysal E, Erturk SM, Yildirim H, Seleker F, Basak M. Sensitivity of immediate and delayed gadolinium-enhanced MRI after injection of 0.5 M and 1.0 M gadolinium chelates for detecting multiple sclerosis lesions. AJR Am J Roentgenol 2007;188:697–702.

Neurology 72

January 6, 2009

79

VIEWS & REVIEWS

Delusional misidentifications and duplications Right brain lesions, left brain delusions

Orrin Devinsky, MD

Address correspondence and reprint requests to Dr. Orrin Devinsky, Departments of Neurology, Psychiatry, and Neurosurgery, NYU Epilepsy Center, 403 E. 34th Street, 4th floor, New York, NY 10016 [email protected]

ABSTRACT

When the delusional misidentification syndromes reduplicative paramnesia and Capgras syndromes result from neurologic disease, lesions are usually bifrontal and/or right hemispheric. The related disorders of confabulation and anosognosis share overlapping mechanisms and anatomic pathology. A dual mechanism is postulated for the delusional misidentification syndromes: negative effects from right hemisphere and frontal lobe dysfunction as well as positive effects from release (i.e., overactivity) of preserved left hemisphere areas. Negative effects of right hemisphere injury impair self-monitoring, ego boundaries, and attaching emotional valence and familiarity to stimuli. The unchecked left hemisphere unleashes a creative narrator from the monitoring of self, memory, and reality by the frontal and right hemisphere areas, leading to excessive and false explanations. Further, the left hemisphere’s cognitive style of categorization, often into dual categories, leads it to invent a duplicate or impostor to resolve conflicting information. Delusions result from right hemisphere lesions. But it is the left hemisphere that is deluded. Neurology® 2009;72:80–87

Delusions are pathologic beliefs that remain fixed despite clear evidence that they are incorrect. They are not conventional beliefs of a culture or religion. Often bizarre in content and held with absolute certainty, delusions can cause significant morbidity. Their pathogenesis in primary psychotic disorders and neurologic disorders remains unknown, with theories encompassing psychological, cognitive, neurochemical, and structural anomalies. This article reviews the cognitive and anatomic systems underlying two delusional misidentification syndromes, reduplicative paramnesia and Capgras syndromes, and related disorders of confabulation and anosognosia. The division between delusions in psychiatric (primary) and neurologic-systemic disorders (secondary) is artificial since psychiatric disorders with delusions (e.g., schizophrenia) have functional and structural brain pathology. Like psychiatric delusions, neurologic misidentification disorders may be associated with paranoia and are usually personally significant. Schizophrenic delusions usually involve 1) influence (e.g., thought control, broadcasting or insertion), 2) persecution or paranoia, and 3) self-significance (e.g., grandeur, reference, religious, guilt). Schizophrenic delusions are not consistently associated with lateralized or localized brain metabolic abnormalities.1 Delusional disorder is a psychotic syndrome with prominent non-bizarre delusions (e.g., my wife is having an affair) lasting for at least 1 month, including erotomania, grandiose, jealous, persecutory, somatic, and mixed. Simple delusions are unstructured, variable, and often paranoid. Complex delusions usually focus on specific content, with an elaborate web of explanations in patients with relatively preserved intellect, as intellect is recruited in the service of the delusion.2 Improved diagnostic techniques have increased identification of neurologic disorders among patients with delusions. For example, Capgras syndrome was a psychiatric disorder 50 years ago, but neurologic disorders are now recognized in most cases.3 A wide spectrum of systemic and neurologic disorders cause simple and complex delusions.4 Content-specific delusions From the Departments of Neurology, Psychiatry, and Neurosurgery, NYU Epilepsy Center, New York, NY. Disclosure: The author reports no disclosures. 80

Copyright © 2009 by AAN Enterprises, Inc.

Table 1

Content-specific delusions

Syndrome

Clinical features

Comments

Capgras3,5,6,13,14,20-22

Familiar persons are impostors or have doubles with different psychic identity

No autonomic response to familiar faces despite conscious recognition (converse of prosopagnosia)

Mirror sign (selfmisidentification)23,24

Misidentification of oneself in the mirror

Able to identify others in the mirror

Foreign reduplicative paramnesia (Capgras for places)25

Familiar place such as home is considered a duplicate in another location

Sometimes labeled reduplicative paramnesia

Disorientation for place26

A familiar place exists in another location

New York Hospital is in Manhattan but Manhattan is in Boston

Fregoli6,14,22,30

A stranger is believed to be a familiar person

A person takes on others’ appearances but retains psychic identity; often persecutes patient

Intermetamorphosis22

Familiar or unfamiliar people change both physical and mental identity

Usually transforms into someone familiar to the patient

Subjective doubles22

Familiar or unfamiliar person is mentally and physically transformed into the patient

The patient considers this other person a double

A place simultaneously exists in two or more physical locations

For example, a strange hospital is duplicated in a hometown setting

Othello (delusional jealousy)31

Belief that a loved one is involved in a sexual or love relation

Patient may repeatedly interrogate, search for evidence, or stalk partner

de Clerambault (erotomania)32

Belief in a reciprocal love relation, often with a famous stranger

Cotard syndrome

Belief that one is dead or dying

Delusional reduplicationmisidentification Loss of familiarity People

Places

Hyperfamiliarity People

Places Reduplicative paramnesia27-29 Other delusions

predominate in neurologic patients3,5,6 (table 1), usually misidentification and reduplication syndromes, with beliefs that places (reduplicative paramnesia), people (Capgras, Fregoli), or events are transformed in identity or duplicated. These delusional syndromes can coexist. RELATED NEUROLOGIC DISORDERS: CONFABULATION AND ANOSOGNOSIA Confabulation and

anosognosia are close kin to delusions. Confabulation refers to incorrect or distorted statements made without a conscious effort to deceive. Confabulation is usually associated with memory (medial temporal or diencephalic) and executive (bifrontal) dysfunction.7-9 If retrieved information cannot be contextually and temporally labeled, past memories blur with current experience. Conscious guidance and maintenance of the search to link the results with past and current experi-

ence, or strategic recall, is often impaired.8 In contrast, the automatic and faster associative recall is intact. Deficits in self-monitoring and linking a memory with its source impairs reality monitoring and the ability to distinguish memory from internally generated thoughts.9 Although confabulation and content-specific delusions can coexist, they differ in features, time course, and neuroanatomy. Patients who confabulate can usually be redirected and corrected while those with delusions cannot. When confabulation and delusional misidentifications concur, confabulation usually resolves first.10,11 The occurrence and resolution of ventromedial and orbital frontal lesions parallels the development and disappearance of confabulation.7,12 Although confabulation and delusions are often caused by bilateral lesions, when pathology is unilateral, there is no lateralized predominance with confabulation,9 but right-sided lesions predominate with delusions.6,13,14 Anosognosia is unawareness of a neurologic defiNeurology 72

January 6, 2009

81

cit, usually affecting vision (Anton syndrome) or movement (anosognosia for hemiplegia). The inability of self to recognize blindness or hemiplegia is striking. Anton syndrome is usually caused by bilateral occipital lesions, but can result from anterior visual system lesions, especially when combined with frontal pathology.15 Patients often confabulate about their visual loss; for example, “it’s just bad lighting.” Babinski coined anosognosia to describe unawareness of left hemiplegia.16 Patients often insist their left arm and leg “can move fine” despite obvious weakness. Although anosognosia for hemiplegia after stroke often recovers over months, the initial false belief in the limb’s strength is a delusion that resists rational explanations and visual demonstrations. Some patients deny ownership of their limb (asomatognosia), often claiming it belongs to someone else. Asomatognosia is a delusion in which the limb’s relation to the self is lost, “Capgras syndrome affecting the arm.”18 Other patients personify the limb with names such as “Floppy Joe” or “Silly Jimmy,” hate the limb (misoplegia), or recognize the deficit but show no concern (anosodiaphoria).17-19 Anosognosia for hemiplegia usually results from large nondominant hemisphere strokes involving parietal, frontal, and temporal lobes as well as the insula and subcortex. Pick reported a 67-year-old woman who developed amnesia, confabulations, paranoid delusions, and seizures after a stroke.27 She believed that the Prague hospital and its doctors, attendants, and patients were simultaneously duplicated in her birth town. When the doctor asked how he could be there as well, she said was “very pleased to see him here too.” When asked about the “peculiarities” of the two clinics, she responded, “today’s clinic is perhaps a continuation of the previous one.” Similarly, after a head injury, a man was repeatedly told and remembered that he was at the Jamaica Plain VA Hospital, but insisted the hospital was in his hometown of Taunton, Massachusetts.29 Some patients misidentify but do not reduplicate their environment. Reduplicative paramnesia most often occurs in patients with neurodegenerative disorders, stroke, and head trauma. Among psychiatric patients, it is associated with bilateral anterior cortical atrophy.28 Patients with reduplicative amnesia often confabulate, confusing memory and imagination. Like confabulation, reduplicative paramnesia is usually associated with executive and memory deficits, but visuospatial and geographic orientation skills are also often impaired.7,25 Patients with reduplicative paramnesia recognize familiar places, landmarks, and REDUPLICATIVE PARAMNESIA

82

Neurology 72

January 6, 2009

objects, suggesting that the ventral occipitotemporal cortex that recognizes these stimuli is preserved. The lesions usually involve bifrontal or right frontal areas.6,7,25 Frontal injury may disinhibit the intact familiarity and landmark areas in the temporal lobes while impairing self-monitoring, meta-memory, and error detection. Familiarity may be falsely triggered by novel stimuli but eludes error detection. Wish fulfillment and motivation may affectively color the choice of duplicated location. Virtually all patients believe that they are in or near their homes or hometowns.33 After resolution of the delusion that the hospital was in their home, four patients “each claimed that their confabulated stories resulted from a desire to be at home.”34 Rarely, patients believe that a familiar setting is reduplicated in a foreign place; i.e., foreign reduplicative paramnesia or Capgras for places. For example, a man with a right frontal hemorrhage returned home by taxi, recognized his wife and daughter, but was sure that his house was not his real home.25 He remarked how “striking it was that the owners of this house had the same ornaments as he had in ‘his’ house and what a coincidence it was that there were similar items beside the bed . . .” CAPGRAS SYNDROME Capgras and ReboulLachaux reported a 53-year-old paranoid megalomanic woman “who transformed everyone in her entourage, even those closest to her, such as her husband and daughter, into various and numerous doubles.”20 Delusional jealousy and grandeur began 8 years earlier, after four children died over a short period, leaving only a daughter. Later, she was convinced that her children were abducted and her surviving daughter was replaced by a look-alike. Thousands of doubles of her daughter passed before her eyes, “every day, sometimes many a day.” Her husband and even she were eventually replaced by doubles. Capgras attributed her delusions to an “agnosia of identification,” postulating that all sensory and memory images struggle between the emotional poles of familiarity and strangeness; he later proposed an Oedipal etiology.21 The Capgras delusion usually involves intimates—a spouse, sibling, child, or neighbor. The paradox of Capgras is the selective duplication of people with whom the patient has strong emotional bonds and associative memories. Capgras patients can consciously recognize familiar faces but cannot emotionally connect with them: the converse of prosopagnosia.35 Prosopagnosia results from bilateral or right-sided lesions in the facial recognition areas (fusiform gyri). Patients may fail to recognize their spouse’s or their own face but generate an uncon-

scious autonomic skin resistance response to familiar faces. Nonconscious and conscious awareness are dissociated. Psychiatric and neurologic Capgras patients fail to generate autonomic responses when viewing photographs of familiar people or famous people.35,36 In some patients, visual information reaches the facial recognition area leading to conscious recognition, but a temporal lesion may disconnect this from the limbic areas that infuse the sparkle of familiarity. This explanation cannot explain most Capgras cases since the temporal lobes may be spared and most cases involve visual and auditory modalities.6 The delusional misidentification-reduplication syndromes can be viewed as pathologic poles of decreased and increased familiarity. Capgras syndrome, the mirror sign, and foreign reduplicative paramnesia cause familiar people or places to become foreign. By contrast, in, Fregoli, intermetamorphosis, and reduplicative paramnesia syndromes, novel people and places “feel” very familiar. Paranoid ideation is common with Capgras syndrome, often preceding the delusion of the imposter.6 In contrast, paranoia is uncommon among patients with reduplicative paramnesia.27-29 LESION LOCALIZATION IN DELUSIONAL MISIDENTIFICATION SYNDROMES Neurologic patients

with delusions usually have lesions in the right hemisphere and/or bifrontal areas.3,5-7,13,14,22-25,37-39 In some cases, a “two-hit” sequence may cause delusions: baseline generalized atrophy with a subsequent right hemisphere injury.37,38 In one study, nine patients with right hemisphere infarctions at a stroke rehabilitation unit had frequent delusions. While size of the stroke did not correlate with delusions when compared to a control group, the presence of brain atrophy was a significant predictor of delusions.38 When delusions occur in patients with widespread brain involvement, if pathology predominates in one hemisphere, it is usually the right. For example, delusional patients with Alzheimer disease have significantly more right frontal hypometabolism.40,41 Reduplicative paramnesia and Capgras syndrome cases with unilateral brain lesions strongly implicate the right hemisphere, usually frontal with variable temporal or parietal involvement. 6,13,14,37,39 Among 69 patients with reduplicative paramnesia, lesions were primarily in the right hemisphere in 36 (52%), bilateral in 28 (41%), and left hemisphere in 5 (7%)39—a sevenfold increase of right- over left-sided lesions (p ⬍ 0.0001). Similarly, among 26 Capgras patients, lesions were primarily in the right hemisphere in 8 (32%), bilateral in 16 (62%), and leftsided in 2 (7%)—a fourfold increase of right-over left-sided lesions (p ⬍ 0.06). For both delusional

syndromes, many bilateral cases had maximal damage in the right hemisphere. Among 29 cases of delusional misidentification syndromes (overlap with prior review), all had right hemisphere pathology, while only 15 (52%) had left hemisphere damage. 6 Fourteen had exclusively right hemisphere damage but none had isolated lefthemisphere damage. When lateralized lesions are found, right hemisphere lesions are more common in other delusional misidentification (Fregoli syndrome, mirror sign) and content specific delusions (Othello, erotomania).24,30-32 Frontal lesions are strongly implicated in misidentification syndromes. Exclusively frontal lesions were associated with delusions in 10/29 (34.5%) cases6: four with right frontal and six with bifrontal lesions. None had lesions sparing the frontal lobes.6 Notably, temporal lesions were present in 7/11 (64%) patients who mistook familiar people, places, or body parts as foreign and 2/14 (14%) who mistook foreign objects or people as familiar. While frontal pathology is often critical for delusions to develop, associated temporal lesions may cause familiar places to appear foreign while temporal sparing may cause foreign places to appear familiar. Observations in patients with bilateral neurodegenerative disorders supports that misidentification of familiar places as foreign is associated with temporal and frontal pathology. A patient with Alzheimer disease with foreign reduplicative paramnesia believed that his home was duplicated in another city; pathology was maximal in frontal and temporal association cortices.42 One study found neurodegenerative disorder in 38/47 (81%) Capgras patients, with Lewy body disease in 26 (55%).3 Many patients believed that there were multiple impostors, and held other delusions such as reduplicative paramnesia. Visual hallucinations, present in 30/38 (79%) of neurodegenerative patients, correlate with the severity of Lewy body deposition in the amygdala, and parahippocampal and inferior temporal cortices.43 Dysfunction in these areas can cause paranoia and visual hallucinations. Patients with Lewy body disease may identify familiar faces, but cannot link the face and emotion. Frontal lobe dysfunction, a neuropsychological hallmark of Lewy body disease,44 may prevent patients from recognizing their errors and changing their false beliefs. The frontotemporal lesions may lead patients to see familiar people or places as foreign; temporal lesions may cause paranoia. PATHOGENESIS A spectrum of cognitive and behavioral disorders may cause or contribute to delusions (table 2).2-6,13-15,45-47 Nearly ubiquitous frontal pathology supports the role of impaired executive, Neurology 72

January 6, 2009

83

Table 2

Pathogenesis of delusions: Possible cognitive and behavioral disorders

Executive function Reasoning Judgment Self-monitoring Reality monitoring Meta-memory (knowledge of memory) Theory of mind Attention (increased signal to noise, false alerts, and threats) Probability-based decision-making Prediction-error signaling Time estimation, context, and sequencing Familiarity versus foreignness Working memory Short-term declarative memory Autobiographical memory Visuospatial Spatial attention Self-representation Ego boundaries Attachment of emotional valence to stimuli Psychiatric-psychological comorbidity Anxiety Paranoia Wish fulfillment Denial Projection Disconnection Frontal executive and temporal emotional areas Facial recognition and emotional areas

theory of mind, decision and prediction making, time estimation and sequencing, meta-memory, and working memory functions. Frontal dysfunction impairs the ability to monitor self and to recognize and correct inaccurate memories and familiarity assessments. The resistance of delusions to change despite clear evidence that they are wrong likely reflects frontal dysfunction. The right frontal lobe likely monitors the appropriateness of familiarity decisions, consistent with right frontal lesions in almost all delusional misidentification syndromes, while the right temporal lobe creates the glow of emotional familiarity.48 The anterior parahippocampal cortex (perirhinal cortex, Brodmann areas 35 and 36) is activated by familiarity, while the hippocampus and posterior parahippocampal cortex mediate recollection.49 Perirhinal cortex stimulation evokes de´ja` vu and de´ja` ve´cu (already experienced).50 Further, the right hemi84

Neurology 72

January 6, 2009

sphere dominates in familiarity decisions14,48; de´ja` vu is more common with right than left temporal lobe seizures or stimulation.48,51 Lesions that destroy or isolate stimuli from right perirhinal cortex may lead to loss of familiarity (e.g., Capgras syndrome) while hyperfamiliarity (i.e., misidentifying strange people as familiar [Fregoli syndrome]) may result from overactivity in right perirhinal cortex from stimulation or disinhibition. Two cases of nondelusional hyperfamiliarity for faces resulted from left-sided lesions (lateral temporal-occipital and anterior cingulate),52,53 possibly disinhibiting right hemisphere areas that imbue faces or places with familiarity. Delusions may develop preferentially after right hemisphere lesions because of 1) loss of self-related functions such as monitoring of reality, memory, and familiarity,6,14,48 and 2) left hemisphere overactivity after loss of right-sided influences. The right hemisphere dominates awareness and image of self and relating perceptual and emotional self to the external and internal environments.6,14,48 Thus, right hemisphere lesions may cause delusions by disrupting the relation between and the monitoring of psychic, emotional, and physical self to people, places, and even body parts.6,14 This explains why contentspecific delusions involve people, places, or things of personal significance and distort their relation to the self. The right hemisphere dominates selfrecognition,54 emotional familiarity,14,50 and ego boundaries.6,14,55 An example is the “response-tonext-patient-stimulation,” found in patients with acute right hemisphere strokes.55 When commands such as open your mouth were directed to the patient in the bed next to them, the stroke patients obeyed the commands. This inability to distinguish verbal information directed at others vs self is a disorder of the ego boundary. Left hemisphere hyperactivity may play a critical role in the pathogenesis of delusions. Jackson recognized many dramatic positive symptoms result from intact brain areas released from control by damaged areas.56 Lesions outside the right temporal lobe may cause nondelusional hyperfamiliarity syndromes by disinhibiting emotional familiarity. In corpus callosotomy patients, when an emotional visual stimulus is selectively presented to the right hemisphere, the left hemisphere may confabulate. One such patient blushed and giggled after her right hemisphere saw a nude picture. When asked what she saw, her left hemisphere responded, “Nothing, just a flash of light.” When asked why she was laughing—“Oh doctor, you have some machine!”57 Another callosotomy patient saw a snow scene in the right hemisphere (left visual field) and chicken claw in the left hemisphere (right visual field). Asked to choose a pic-

ture card that related to what was seen, the left hand chose a shovel and the right hand picked a chicken. When asked what he saw: “I saw a claw and I picked the chicken, and you have to clean out the chicken shed with a shovel.”58 Similarly, when a picture of a hurdler was flashed to the right hemisphere, the word “athlete” was offered, presumably by the right hemisphere. The left hemisphere then went on, “a basketball guy . . . had a uniform.”59 These confabulatory responses reflect the left hemisphere’s “creative and incorrect filling in.”59 Gazzaniga referred to the left hemisphere’s narrative talent that extends to fiction as the interpreter mechanism: “ . . . always hard at work, seeking the meaning of events. It is constantly looking for order and reason, even when there is none—which leads it continually to make mistakes. It tends to over-generalize, frequently constructing a potential past as opposed to a true one.”59 Release of the left hemisphere’s creative narrator from the monitoring of self, memory, and familiarity by the right frontal lobe may lead to excessive or false explanations. In callosotomy patients, testing is often done months after surgery and the frontal lobes are usually intact, accounting for the lack of delusions. For visual perception and mental imagery, the right hemisphere is stronger at encoding overall patterns, representing specific instances, and mapping coordinate spatial relations. The left hemisphere encodes component parts, represents categories, and encodes categorical relations.60 Spatially, the left hemisphere dominates at dual categorical choices such as up vs down and left vs right. In callosotomy patients, the right hemisphere can point to a state’s location and then draw its shape, but the left hemisphere can tell whether state is north/south or east/ west of another. Thus, a left hemisphere released from the right may be overbiased to categorize, but without the right hemisphere’s gestalt and emotional familiarity. This combination may explain the bizarre invention of an impostor or duplicate. The left hemisphere recognizes “she is my wife,” but fails to receive other information (sparkle of familiarity, global gestalt, and relation to self) and concludes that “she is not my wife.” The conflict is resolved with a fabrication, a dual category: a duplicate or impostor. She looks like my wife, but she really isn’t my wife. Right frontal injury impairs monitoring of feedback from others and self, leading to false memories and delusions that resist erasure, despite evidence that they are incorrect. Similarly, in anosognosic patients, the left hemisphere of an adult with superior verbal intelligence cannot understand evidence (i.e., the right side is weak) that a young child immediately grasps linguistically or visually. The left hemisphere just does not get it. Delusions result from right hemi-

sphere lesions. But it is the left hemisphere that is deluded. Our knowledge of delusions is limited by our ability to comprehend the patient’s irrational thought process. The hypothesis and mechanisms put forth in this article remain speculative. The presence of similar lesions without delusions argues against but is not a fatal flaw for the hypothesis. The pathogenesis of delusions likely includes many mechanisms that span overlapping psychological, cognitive, and neurologic disorders. Individual differences in the all three areas may interact to produce complex clinical patterns. Yet common elements may contribute to creation and persistence of delusions in diverse psychiatric and neurologic disorders. Future research should explore the psychological, cognitive, and physiologic-anatomic systems that change during the emergence and resolution of delusions, as well as strategies to treat delusions (e.g., reducing left hemisphere overactivity). Received July 29, 2008. Accepted in final form September 22, 2008.

REFERENCES 1. Lahti AC, Weiler MA, Holcomb HH, Tamminga CA, Carpenter WT, McMahon R. Correlations between rCBF and symptoms in two independent cohorts of drug-free patients with schizophrenia. Neuropsychopharmacology 2006;31:221–230. 2. Cummings JL. Organic delusions. Br J Psychiatry 1985; 46:184–197. 3. Joseph KA. Capgras syndrome and its relationship to neurodegenerative disease. Arch Neurol 2007;64:1762–1766. 4. Gorman DG, Cummings JL. Organic delusional syndrome. Semin Neurol 1990;10:229–238. 5. Malloy PF, Richardson ED. The frontal lobes and contentspecific delusions. J Neuropsychiatry 1994;6:455–466. 6. Feinberg TE, Deluca J, Giacino JT, Roane DM, Solms M. Right-hemisphere pathology and the self: delusional misidentification and reduplication. In: Feinberg TE, Keenan JP, eds. The Lost Self. New York: Oxford University Press; 2005:100 –130. 7. Benson DF, Djenderedjian A, Miller BL, et al. Neural basis of confabulation. Neurology 1996;46:1239–1243. 8. Moscovitch M, Melo B. Strategic recall and the frontal lobes: evidence from confabulation and amnesia. Neuropsychologia 1997;35:1017–1034. 9. Johnson MK, Hayes SM, D’Esposito M, Raye CL. Confabulation. In: Grafman J, Boller F. Handbook of Neuropsychology, 2nd Ed. Amsterdam: Elsevier Science; 2000: 383– 407. 10. Box O, Laing H, Kopelman M. The evolution of spontaneous confabulation, delusional misidentification and a related delusion in a case of severe head injury. Neurocase 1999;5:251–262. 11. Mattioli F, Miozzo A, Vignolo LA. Confabulation and delusional misidentification: A four year followup study. Cortex 1999;35:413–422. 12. Deluca J, Diamond BJ. Aneurysm of the anterior communicating artery: a review of neuroanatomical and neuropsyNeurology 72

January 6, 2009

85

13.

14.

15.

16.

17. 18. 19. 20.

21. 22.

23.

24.

25.

26. 27. 28.

29. 30.

31.

32.

33.

86

chologic sequelae. Clin Exp Neuropsychol 1995;17:100– 121. Malloy P, Cimino C, Westlake R. Differential diagnosis of primary and secondary Capgras delusions. Neuropsychiatry Neuropsychol Behav Neurol 1992;2:83–96. Devinsky O. Right cerebral hemisphere dominance for a sense of corporeal and emotional self. Epilepsy Behav 2000;1:60–73. Feinberg TE, Roane DM. Anosognosia, completion and confabulation: the neutral-personal dichotomy. Neurocase 1997;3:73–85. Babinski J. Contribution a l’etude des mentaux dans l’hemiplegie organique (anosognosie). Rev Neurol 1914; 27:845–848. Critchley M. Observations on anosodiaphoria. Encephale 1953;46:540–546. Critchley M. Personification of paralyzed limbs in hemiplegics. BMJ 1955;30:284. Critchley M. Misoplegia or hatred of hemiplegia. Mt Sinai J Med 1974;41:82–87. Capgras J, Reboul-Lachaux J. Illusion des sosies dans un delire systematise chronique. Bulletin de la societe clinique de medicine mentale 1923;2:6–16. Capgras J, Carette P. Illusion des sories et complexe d’Oedipe. Ann Medico-Psychologiques 1924;12:48. Fo¨rstl H, Almeida OP, Owen AM, Burns A, Howard R. Psychiatric, neurological and medical aspects of misidentification syndromes: a review of 260 cases. Psychol Med 1991;21:905–910. Breen N, Caine D, Coltheart M. Mirrored-self misidentification: two cases of focal onset dementia. Neurocase 2001;7:239–254. Postal KS. The mirror sign delusional misidentification symptom. In: Feinberg TE, Keenan JP. The Lost Self: Pathologies of the Brain and Identity. New York: Oxford University Press; 2005:131–146. Kapur N, Coughlan AK. Confabulation and frontal lobe dysfunction. J Neurol Neurosurg Psychiatry 1980;43: 461–463. Fisher CM. Disorientation for place. Arch Neurol 1982; 39:33–36. Pick A. Clinical studies. Brain 1903;26:242–267. Joseph AB, O’Leary DH, Kurland R, Ellis HD. Bilateral anterior cortical atrophy and subcortical atrophy in reduplicative paramnesia: a case-control study of computed tomography in 10 patients. Can J Psychiatry 1999;44:685–689. Benson DF, Gardner H, Meadows JC. Reduplicative paramnesia. Neurology 1976;26:147–151. de Pauw KW, Szulecka TK, Poltock TL. Fre´goli syndrome after cerebral infarction. J Nerv Ment Dis 1987;175:433– 438. Narumoto J, Nakamura K, Kitabayashi Y, Fukui K. Othello syndrome secondary to right orbitofrontal lobe excision. J Neuropsychiatry Clin Neurosci 2006;18:560– 561. El Gaddal YY. De Clerambault’s syndrome (erotomania) in organic delusional syndrome. Br J Psychiatry 1980;154: 714–716. Turnbull OH, Berry H, Evans CE. A positive emotional bias in confabulatory false beliefs about place. Brain Cogn 2004;55:490–494.

Neurology 72

January 6, 2009

34.

35.

36.

37.

38. 39.

40.

41.

42.

43.

44.

45.

46. 47.

48.

49.

50.

51.

52.

Ruff RL, Volpe BT. Environmental reduplication associated with right frontal and parietal lobe injury. J Neurol Neurosurg Psychiatry 1981;44:382–386. Ellis HD, Young AW, Quayle AH, de Pauw KW. Reduced autonomic responses to faces in Capgras delusion. Proc Biol Sci 1997;264:1085–1092. Hirstein W, Ramachandran VS. Capgras syndrome: a novel probe for understanding the neural representation of the identity and familiarity of persons. Proc Biol Sci 1997; 264:437–444. Alexander MP, Stuss DT, Benson DF. Capgras syndrome: a reduplicative phenomenon. Neurology 1979;29:334– 339. Levine DN, Grek A. The anatomic basis of delusions after right cerebral infraction. Neurology 1984;34:577–582. Feinberg TE, Shapiro RM. Misidentification-reduplication and the right hemisphere. Neuropsychiatry Neuropsychol Behav Neurol 1989;2:39–48. Sultzer DL, Brown CV, Mandelkern MA, et al. Delusional thoughts and regional frontal/temporal cortex metabolism in Alzheimer’s disease. Am J Psychiatry 2003;160:341– 349. Nakano S, Yamashita F, Matsuda H, Kodama C, Yamada T. Relationship between delusions and regional cerebral blood flow in Alzheimer’s disease. Dement Geriatr Cogn Disord 2006;21:16–21. von Gunten A, Miklossy J, Suva` ML, Hof PR, Glannakopoulos P. Environmental reduplicative paramnesia in a case of atypical Alzheimer’s disease. Neurocase 2005;11:216–226. Harding AJ, Broe GA, Halliday GM. Visual hallucinations in Lewy body disease relate to Lewy bodies in the temporal lobe. Brain 2002;125:391–403. McKeith IG, Perry RH, Fairbairn AF, Jabeen S, Perry EK. Operational criteria for senile dementia of Lewy body type (SDLT). Psychol Med 1992;22:911–922. Corlett PR, Murray GK, Honey GD, et al. Disrupted prediction-error signal in psychosis: evidence for an associative account of delusions. Brain 2007;130:2387–2400. Kunert HJ, Norra C, Hoff P. Theories of delusional disorders. Psychopathology 2007;40:191–202. Maher BA. Anomalous experience and delusional thinking: The logic of explanations. In: Oltmanns TF, Maher BA, eds. Delusional Beliefs. New York: Wiley; 1988: 15–33. Gainotti G. Face familiarity feelings, the right temporal lobe and the possible underlying neural mechanisms. Brain Res Rev 2007;56:214–235. Bowles B, Crupi C, Mirsattari SM, et al. Impaired familiarity with preserved recollection after anterior temporallobe resection that spares the hippocampus. Proc Natl Acad Sci 2007;104:16382–16387. Vignal J-P, Maillard L, McGonigal A, Chauvel P. The dreamy state: hallucinations of autobiographic memory evoked by temporal lobe stimulations and seizures. Brain 2007;130:88–89. Mullan S, Penfield W. Illusions of comparative interpretation and emotion. Arch Neurol Psychiatry 1959;81:269– 284. Vuilleumier P, Mohr C, Valenza N, Wetzel C, Landis T. Hyperfamiliarity for unknown faces after left lateral temporo-occipital venous infarction: a double dissociation with prosopagnosia. Brain 2003;126:889–907.

53.

Nente F, Carrillo-Mezo R, Mendez MF, RamirezBermudez J. Pathological hyperfamiliarity for others from a left anterior cingulate lesion. J Neuropsychiatry Clin Neurosci 2007;19:345–346. 54. Keenan JP, Wheeler M, Platek SM, Lardi G, Lassonde M. Self-face processing in a callosotomy patient. Eur J Neurosci 2003;18:2391–2395. 55. Bogousslavsky J, Regli F. Response-to-next-patient-stimulation: a right hemisphere syndrome. Neurology 1988;38:1225–1227. 56. Jackson JH. Evolution and dissolution of the nervous system. In: Taylor J, ed. Selected Writings of John Hughlings

57.

58. 59. 60.

Jackson, Volume 2. New York: Basic Books; 1884/1958: 45–75. Sperry RW, Zaidel E, Zaidel D. Self recognition and social awareness in the deconnected minor hemisphere. Neuropsychologia 1979;17:153–166. Gazzaniga MS. Cerebral specialization and interhemispheric communication. Brain 2000;123:1296–1326. Gazzaniga MS. The split brain revisited. Sci Am 1998;279: 50–55. Brown HD, Kosslyn SM. Cerebral lateralization. Curr Opin Neurobiol 1993;3:183–186.

Use Dendrite to Find Your Next Job Looking to take the next important step in your career? Or are you hoping to reach more than 21,000 neuroscience professionals for your open positions in neurology? Look no further than AAN Dendrite: Careers in Neurology! Search hundreds of employment opportunities in neurology across the US and Canada. Employers: maximize your range and impact for job postings with a Dendrite ad and find the perfect fit for your posting. Print and online listings for one price. Make your next step in neurology count; go now: www.aan.com/neurologyjobs.

New Categories of Resident & Fellow Section Clinical Reasoning: Case presentations to aid in developing clinical reasoning skills. Right Brain: Neurology and the medical humanities — history, literature, and arts. Child Neurology: Patient case with detailed discussion about topic of focus. Pearls and Oy-sters: Clinical insights (pearls) and advice for avoiding mistakes (oysters). International: Educational exchanges, experiences in low and middle income countries. Emerging Subspecialities: History of fields such as Pain Medicine and Headache. Continue to submit articles about education research and educational topics, training videos, and teaching NeuroImages!

Neurology 72

January 6, 2009

87

HISTORICAL NEUROLOGY

O. Buda, MD, PhD, Bphil D. Arsene, MD, PhD M. Ceausu, MD, PhD D. Dermengiu, MD, PhD G.C. Curca, MD, PhD

Address correspondence and reprint requests to Dr. Octavian Buda, Mina Minovici National Institute of Legal Medicine, Sos. Vitan-Birzesti 9, 042122 Bucharest 4, Romania [email protected]

Georges Marinesco and the early research in neuropathology

ABSTRACT

Objective: To present the scientific contributions of Georges Marinesco (1863–1938) and place his achievements within the context of early neuropathology research.

Background: Neuropathology is a relatively recent medical field, its origins dating to the late 19th century.

Results: One of the most important neuroscientists of that period was the Romanian-born Georges Marinesco. He became a neurologist under Charcot’s guidance at the Salpe ˆtrie `re Hospital, in Paris. In 1892, Paul Blocq and Marinesco gave a first account of senile plaques, having used their pathologic skills in the examination of nine deceased epileptic patients. They did not, however, relate the plaques to dementia. Marinesco made discoveries in neuropathology which he described from a histopathologic perspective, and introduced new medical terms such as neuronophagia, chromatolysis, and medullomyoblastoma. He also drew correlations between clinical neurologic findings and morphology, for example in congenital cerebellar ataxia, syringomyelia, and parkinsonism. From 1899 he used cinematography as a medical research tool.

Conclusion: Marinesco was a prolific researcher in the field of neuropathology, especially neurodegeneration but also in clinical neurology. He is now considered the founder of the modern Romanian school of neurology. Neurology® 2009;72:88–91

In 1672, Thomas Willis established a correlation between brain atrophy and cognitive impairment, in the earliest English work on the pathology of the brain and medical psychology, “Two Discourses Concerning the Soul of Brutes, Which is That of the Vital and Sensitive of Man.”1 This can be considered a modern impulse for the science which would, much later, become known as neuropathology. The search for the essential neuropathological ingredients of “involutional psychosis” started during the second half of the 19th century.2 In 1868, the French neurologist Jean-Martin Charcot initiated a series of 24 lectures on diseases affecting the elderly, at the Salpeˆtrie`re Hospital in Paris.3,4 Charcot’s first lecture concerned the “general characteristics of senile pathology.”5 During the same period, the Romanian-born Georges Marinesco (figure 1) undertook postgraduate training in neurology under Charcot’s guidance at the Salpeˆtrie`re. During his training, he also worked with some other leading names of French neurology, such as Pierre Marie, Joseph Babinski, and Fulgence Raymond. Marinesco was also keen to use histologic techniques in the study of microscopic lesions occurring within the brain, for example Golgi’s impregnation with silver nitrate (1873). Later Marinesco worked with Carl Weigert in Frankfurt and then with Emil Du Bois-Raymond in Berlin. In 1890, in collaboration with the French pathologist Paul Blocq, he wrote a study of the pathologic findings discovered in Friedreich disease. In 1891, Marinesco lectured on changes in the spinal marrow in cases of amputation at the French Society of Psychiatrists. In Berlin in 1892, Marinesco—together with Blocq and the Romanian pathologist and bacteriologist Victor Babes—published an atlas of the pathologic histology of the nervous system.6 During the 1890s, Marinesco also became interested in the mechanisms of neurodegeneration. His findings were one of the main elements later used by Alzheimer (together with his own painstaking clinical and GEORGES MARINESCO

From the Mina Minovici National Institute of Legal Medicine (O.B., M.C., D.D., G.C.C.) and Victor Babes National Institute of Pathology (D.A.), Bucharest, Romania. Disclosure: The authors report no disclosures. 88

Copyright © 2009 by AAN Enterprises, Inc.

Figure 1

Georges Marinesco, 1863–1938

pathologic observations) to create a cohesive description of senile dementia. In 1892, Blocq and Marinesco described a lesion in the postmortem brains of chronic epileptic patients which represented the now familiar senile plaques found in patients with dementia. The original French article,7 entitled “On the lesions and pathogeny of the so-called essential epilepsy,” was published in the Parisian medical journal La Semaine Me´dicale (figure 2). The study was conducted between 1890 and 1892 at the Salpeˆtrie`re Hospital (courtesy of Charcot), on eight deceased epileptic patients aged 50 to 68, and a ninth aged 29 at the time of death. Blocq and Marinesco performed their examinations using stains common to that period, such as hematoxylin and eosin, acidic fuchsin, and carmine, as well as Marchi’s impregnation, a technique used for demonstrating degenerate myelin with osmium tetroxide. They also modified the staining techniques for glia, previously developed by Santiago Ramon y Cajal. In their study, only one case received special attention because they found round, small aggregates, about 60 ␮m in diameter, disseminated in various layers of the cortex. These were contrasted with the background tissue by an intense stain and well defined contour. They considered these structures, which had a dot-like appearance, to be “nodules of nevroglial sclerosis.” Blocq and Marinesco summarized their research from a strictly anatomic point of view: in a certain number of idiopathic epilepsy cases, there are no detectable lesions of nervous centers. How-

Figure 2

Paris Medical Weekly, November 12, 1892

ever, when lesions are detected, they are very variable. The most constant lesions, when they exist, are found in psychomotor regions. In 1911, Simchowicz named the small, discrete masses of argyrophilic particles, having an average diameter of 50 – 60 ␮m, senile plaques. He was the one who concluded that there is an association between these degenerative changes and dementia.8,9 Blocq and Marinesco’s description of these aggregates disseminated within the cortex is, most probably, a first description of the senile plaques characteristic to the dementia associated with aging and Alzheimer disease.10,11 Marinesco also made some discoveries in neuropathology and coined new medical terms after he described them from a histopathologic standpoint. His other studies, published in French, encompassed aging,12 neurodegeneration, and also tumors and general histopathology of the nervous tissue. Marinesco bodies (MB) are eosinophilic ubiquitinated intranuclear inclusions found in pigmented neurons of the human substantia nigra and in the locus ceruleus of humans and monkeys.13 Their formation represents a cellular reaction to stress, but is not always associated with neuronal degeneration.14 Traditionally, MBs have been considered nonpathologic entities. However, MARINESCO’S FURTHER RESEARCH

Neurology 72

January 6, 2009

89

more recent studies indicate that they are associated with age-related degenerative changes in the substantia nigra and striatal loss of dopaminergic terminals. MBs could mark a pathologic process that may contribute to age-related motor dysfunction and Lewy body disorders.15 They are reported mainly in patients with hepatic encephalopathy but are also considered a reaction to stress in aging.16 Intranuclear ubiquitin immunoreactivity of the pigmented substantia nigra neurons in the midbrain, in the form of MBs, has been found to be induced by a fatal severe stress on the CNS in some cases of asphyxia and drowning.17 Marinesco studied the mechanism of aging related to the death of nerve cells, and presented a lecture on this topic to a session of the Acade´mie Royale des Sciences in Paris.18 In this study he detailed special concepts such as senile chromatolysis and neuronophagia (or neuronophagy). Chromatolysis is represented by the loss of Nissl substance in neurons, mostly in cases of cell injury with axotomy, but also in cases of motor neuron disease, Pick disease, corticonigral degeneration, or pellagra. The term was apparently correctly defined by Marinesco in 1909.19 Neuronophagia represented a collection of inflammatory cells around neurons, or in spaces where neurons had been detected in Werdnig-Hoffmann disease and polio infections.20 These two terms remain in the medical vocabulary today. Marinesco also performed research in the field of surgical neuropathology. In 1933, he introduced a special type of embryonic tumor of the nervous system, the medullomyoblastoma.21 This is a rare tumor of the cerebellum having both a primitive neuroectodermal and a striated muscle component.22 In the field of clinical neurology, Marinesco’s 1897 doctoral thesis described “The Succulent Hand in Syringomyelia,” a cold blue edematous hand with lividity of the skin which can be shown in some neurologic lesions such as syringomyelia. This clinical sign is now known as Marinesco’s hand. In 1893, Marinesco and Blocq reported a case of parkinsonian tremor due to a tumor in the substantia nigra. This case was the basis for Edouard Brissaud’s theory, announced the next year, that parkinsonism occurs as a consequence of damage to the substantia nigra.23 In 1931, Marinesco published the clinical features of a rare congenital disorder24 which is now known as the Marinesco-Sjo¨gren syndrome (MSS). This syndrome is characterized by cerebellar ataxia due to cerebellar atrophy with Purkinje and granule cell loss, myopathy by marked muscle replacement with fat and connective tissue, variation in fiber size, atrophic and necrotic myofibers, rimmed vacuoles, and auto90

Neurology 72

January 6, 2009

phagic vacuoles with membranous whirls on electron microscopy. Other cardinal clinical signs include bilateral cataracts, hypergonadotropic hypogonadism, and mild to severe mental retardation. Today MSS is defined as a disease of endoplasmic reticulum dysfunction. Recent studies have confirmed the genetic linkage of the disease phenotype to locus 5q31 and suggest that the disturbed SIL1-HSPA5 interaction and protein folding is the primary pathology in MSS.25 Another clinical feature described by Marinesco is the contraction of the muscles of the chin, in response to stimulation of the thumb. The phenomenon, known as the palmomental Marinesco-Radovici reflex, indicates damage to the corticobulbar tract in a variety of brain diseases, including vascular dementia, amyotrophic lateral sclerosis, or pyramidal lesions.26 Three years after the Lumie`re brothers presented their first movie, Marinesco recorded on film in 1899 the walk of several patients with equilibrium disturbances. He focused his studies particularly on organic locomotor ataxia, gait disorders, and hysteria. Between 1899 and 1902, Marinesco managed to use cinematography as a research tool in neurology and published five articles based on his film recordings.27 The year 2008 marks 145 years since the birth of Georges Marinesco and 70 years since his death. ACKNOWLEDGMENT The authors thank Katherine Watson, DPhil, of Oxford Brookes University, UK, and Mihai Herescu, DMD, DDS, of the Carol Davila Medical University, Bucharest, Romania, for comments regarding this article.

Received May 1, 2008. Accepted in final form September 23, 2008.

REFERENCES 1. Willis T. De Anima Brutorum quae Hominis Vitalis ac Sensitiva est. London: Davis; 1672. 2. Foerst H. Uncommon causes of dementia: an historical account, Int Psychogeriatr 2005;17:S3–S15. 3. Charcot JM. Clinical Lectures on Senile and Chronic Diseases. London: New Sydenham Society; 1881. 4. Berrios GE. Dementia and aging since the nineteenth century. In: Huppert FA, Brayne C, O’Connor DW, eds. Dementia and Normal Aging. New York: Cambridge University Press; 1994:15– 40. 5. Berrios GE. Affective disorders in old age: a conceptual history, Int J Geriatr Psychiatry 1991;6:337–346. 6. Blocq P, Babes V, Marinesco G. Atlas der pathologischen Histologie des Nervensystems. Berlin: Hirschwald; 1892. 7. Blocq P, Marinesco G. Sur les lesions et la pathogenie de l’epilepsie dite essentielle. La Semaine Medicale 1892;12: 445–446. 8. Simchowicz T. Histologische Studien ueber die senile Demenz. In: Nissl F, Alzheimer A, eds. Histologische und histopathologische Arbeiten uber die Grosshirnrinde mit besonderer Beruecksichtigung der pathologischen Anatomie der Geistekrankheiten. Jena: Fischer; 1911:267– 444.

9.

10. 11. 12. 13.

14.

15.

16.

17.

Roth M, Tomlinson BE, Blessed G. Correlation between scores for dementia and counts of ‘senile plaques’ in cerebral grey matter of elderly subjects. Nature 1966;209:109–110. Terry RD. Alzheimer’s disease and the aging brain. J Ger Psychiatry Neurol 2006;19:125–128. Goedert M, Ghetti B. Alois Alzheimer: his life and times. Brain Pathol 2007;17:57–62. Marinesco G. Nouvelles recherches sur les plaques seniles. L’Encephale 1928;8:697–723. Woulfe J, Gray D, Prichett-Pejic W, Munoz DG, Chretien M. Intranuclear rodlets in the substantia nigra: interactions with Marinesco bodies, ubiquitin, and promyelocytic leukemia protein. J Neuropathol Exp Neurol 2004;63: 1200–1207. Kumada S, Uchihara T, Hayashi M, et al. Promyelocytic leukemia protein is redistributed during the formation of intranuclear inclusions independent of polyglutamine expansion: an immunohistochemical study on Marinesco bodies. J Neuropathol Exp Neurol 2002;61:984–991. Beach TG, Walker DG, Sue LI, Newell A, Adler CC, Joyce JN. Substantia nigra Marinesco bodies are associated with decreased striatal expression of dopaminergic markers. J Neuropathol Exp Neurol 2004;63:329–337. Fujigasaki H, Uchihara T, Takahashi J, et al. Preferential recruitment of ataxin-3 independent of expanded polyglutamine: an immunohistochemical study on Marinesco bodies. J Neurol Neurosurg Psychiatry 2001;71:518–520. Quan L, Zhu BL, Ishida K, et al. Intranuclear ubiquitin immunoreactivity of the pigmented neurons of the substantia nigra in fatal acute mechanical asphyxiation and drowning. Int J Legal Med 2001;115:6–11.

18. 19.

20.

21.

22.

23.

24.

25.

26. 27.

Marinesco G. Mecanisme de la senilite et de la mort des cellules nerveuses. CR Hebd Acad Sci 1900;130:1136–1139. Afifi AK, Bergman RA. Neurohistology. In: Afifi AK, Bergman RA, eds. Functional Neuroanatomy. Text and Atlas. 2nd ed. New York: McGraw-Hill; 2005:1–23. Hirano A. Neurons and astrocytes. In: Davis RL, Robertson DM, eds. Textbook of Neuropathology. 3rd ed. Baltimore: Williams & Wilkins; 1997:1–109. Marinesco G, Goldstein M. Sur une forme anatomique, non encore decrite, de medulloblastome: medullo-myoblastome. Ann Anat Pathol 1933;10:513–525. Giordana MT, Wiestler OD. Medullomyoblastoma. In: Kleihues P, Cavenee WK, eds. Pathology and Genetics. Tumours of the Nervous System. Lyon: IARC Press; 2000: 104 –105. Blocq P, Marinesco G. Sur un cas de tremblement parkinsonien hemiplegique symptomatique d’une tumeur du pedoncle cerebral. CR Soc Biol 1893;5:105–111. Marinesco G, Draganescu S, Vasiliu D. Nouvelle maladie familiale caracterisee par une cataracte congenitale et un arret du developement somato-neuro-psychique. L’Encephale 1931;26:97–109. Anttonen AK, Mahjneh I, Hamalainen RH, et al. The gene disrupted in Marinesco-Sjogren syndrome encodes SIL1, an HSPA5 cochaperone. Nature Genet 2005;37: 1309–1311. Marinesco G, Radovici A. Sur un reflexe cutane nouveau: le reflexe palmo-mentonnier. Rev Neurol 1920;27:237–240. Barboi AC, Goetz CG, Musetoiu R. The origins of scientific cinematography and early medical applications. Neurology 2004;62:2082–2086.

Neurology 72

January 6, 2009

91

Clinical/Scientific Notes

Sashank Prasad, MD Robert W. Hurst, MD Scott E. Kasner, MD

POSTPARTUM THROMBOSIS OF A DEVELOPMENTAL VENOUS ANOMALY

Figure

MRI and angiography findings

Developmental venous anomaly (DVA) is a common congenital vascular abnormality that typically has a benign natural history. The lesion likely occurs after atresia or thrombosis of normal venous structures, leading to compensatory retention of embryologic medullary venules.1,2 These venules form an umbrella- shaped arrangement (caput medusae) and cluster into a large central vein that drains into the deep or superficial venous system.1,2 Spontaneous thrombosis of the central vein of a DVA can rarely occur, and lead to symptomatic nonhemorrhagic venous infarction.2-7 Most reported cases of DVA thrombosis demonstrate no underlying predisposition.2-6 One report of nonhemorrhagic venous infarction attributes thrombosis to hypercoagulability induced by puerperium, oral contraceptive use, and smoking.7 We report a case of DVA thrombosis occurring in a postpartum patient on hormonal contraception.

Supplemental data at www.neurology.org

92

Case report. A 16-year-old G1P1 woman presented after three brief simple motor seizures involving the right arm and face occurring over 3 days. She denied persistent symptoms. After the first seizure, she had presented to another hospital and was treated with phenytoin, but did not undergo any neuroimaging studies. Four years previously, she had three episodes of right face, arm, and leg shaking, lasting 2 minutes, without altered consciousness. A routine EEG revealed occipital slowing, but no epileptiform discharges. Brain MRI revealed multiple small vessels draining into an enlarged vein in the left frontal lobe, representing a venous angioma (figure, A). The patient was lost to follow-up, and no antiepileptic agents were started. Three weeks prior, in the 40th week of pregnancy, she was presumptively diagnosed with mild preeclampsia on the basis of elevated blood pressure (146/96 mm Hg) but without proteinuria or edema. She had a 20minute episode of right face and arm shaking with secondary generalization, which was presumed to be an eclamptic seizure. She was treated with IV magnesium and diazepam. A head CT was reportedly negative. She Neurology 72

January 6, 2009

Gadolinium-enhanced T1-weighted MRI revealed left frontal developmental venous anomaly (A, June 2003; B, September 2007, thrombosis within draining vein, with absent flow-void; C, November 2007, resolution of thrombosis). Conventional angiogram (D, left internal carotid artery injection, oblique view) revealed thrombosis of the draining vein (red arrow) of a DVA (yellow arrow). There is delayed emptying of the medullary veins into the late venous phase. See video on the Neurology® Web site at www.neurology.org.

underwent emergent Cesarean section. She recovered fully, and no additional studies were performed. The patient had no other medical illnesses, and there was no relevant family history. Immediately after her delivery, she had received the contraceptive

M. Bitoun, PhD J.A. Bevilacqua, MD, PhD B. Eymard, MD, PhD B. Prudhon, MSc M. Fardeau, MD P. Guicheney, PhD N.B. Romero, MD, PhD

depot medroxyprogesterone acetate (DMPA). She was on no other medications. She denied smoking. The entire examination was normal, including mental status, cranial nerves, strength, sensation, coordination, reflexes, and gait. Noncontrast CT scan of the head revealed a region of hyperdensity within the left frontal lobe. Brain MRI revealed a partially thrombosed venous angioma with surrounding areas of swelling and edema (figure, B). Diffusion-weighted imaging revealed no evidence of restricted diffusion. Gradient echo sequences showed susceptibility artifact within the venous angioma and many of its periventricular branches. Postgadolinium images demonstrated dilated medullary veins and hyperintensity within an enlarged superficial draining vein. Digital subtraction angiography was performed, and injection of the left common carotid artery demonstrated a tangle of small vessels in the posterior left frontal lobe filling during the late venous phase, compatible with a venous angioma (figure, D; video). Emptying of the medullary veins was delayed, suggesting thrombosis of the major draining vein. No aneurysm or arteriovenous malformation was noted and the dural venous sinuses were patent. Blood cell counts and coagulation profiles were normal. Protein C and S levels, antithrombin III level, and homocysteine level were normal. Activated protein C resistance was not present. Antinuclear antibody, anticardiolipin antibody, anti ␤2-glycoprotein antibody, factor V Leiden mutation, and prothrombin gene mutation were negative. The patient was treated with warfarin (goal INR 2.0 –3.0) and levetiracetam. At 3-month follow-up, she reported no further seizures. Repeat MRI and MRA demonstrated resolution of thrombosis within the DVA (figure, C). Warfarin was discontinued. At 6-month follow-up, levetiracetam was discontinued.

sinus thrombosis. Management of this condition should include evaluation for inherited thrombophilia and short-term anticoagulation. Given the relatively benign natural history of DVAs, the risks of hemorrhage during the course of short-term anticoagulation are expected to be minimal, while the benefits of anticoagulation for cerebral venous sinus thrombosis may be substantial. Surgical resection of a DVA is not recommended since the vessel may be the only venous drainage for the surrounding brain parenchyma.1

Discussion. Although DVAs are considered to be relatively benign, there is growing recognition that they may cause venous infarction or hemorrhage. Our patient demonstrates that thrombosis of a DVA may occur in the hypercoagulable state induced by puerperium and hormonal contraception, and possibly preeclampsia, which are risk factors for venous

6.

A NEW CENTRONUCLEAR MYOPATHY PHENOTYPE DUE TO A NOVEL DYNAMIN 2 MUTATION

identified in CNM.2,3 Mutations in the middle domain of the protein are mostly associated with the slowly progressive mild late-onset CNM,2 while mutations in the C-terminal part of the Pleckstrin homology (PH) domain cause a more severe neonatal phenotype.3 In addition, mutations in the N-terminal part of PH domain have been reported in intermediate and axonal CharcotMarie-Tooth disease (CMT).4-6 Here, we report a novel

Autosomal dominant centronuclear myopathy (CNM) is a rare congenital myopathy mostly characterized by delayed motor milestones, slowly progressive muscle weakness, and bilateral ptosis.1 Mutations in the DNM2 gene encoding dynamin 2 (DNM2), a large GTPase involved in membrane trafficking, have been

From the Departments of Neurology (S.P., S.E.K.) and Radiology (R.W.H.), Hospital of the University of Pennsylvania, Philadelphia. Disclosure: The authors report no disclosures. Received March 28, 2008. Accepted in final form July 3, 2008. Address correspondence and reprint requests to Dr. Sashank Prasad, Department of Neurology, Hospital of the University of Pennsylvania, 3W Gates Bldg., 3600 Spruce Street, Philadelphia, PA 19104; [email protected] Copyright © 2009 by AAN Enterprises, Inc. 1.

2.

3.

4.

5.

7.

Agazzi S, Regli L, Uske A, Maeder P, de Tribolet N. Developmental venous anomaly with an arteriovenous shunt and a thrombotic complication: case report. J Neurosurg 2001;94:533–537. Peltier J, Toussaint P, Desenclos C, Le Gars D, Deramond H. Cerebral venous angioma of the pons complicated by nonhemorrhagic infarction: case report. J Neurosurg 2004;101:690–693. Lai PH, Chen PC, Pan HB, Yang CF. Venous infarction from a venous angioma occurring after thrombosis of a drainage vein. AJR Am J Roentgenol 1999;172:1698– 1699. Konan AV, Raymond J, Bourgouin P, Lesage J, Milot G, Roy D. Cerebellar infarct caused by spontaneous thrombosis of a developmental venous anomaly of the posterior fossa. AJNR Am J Neuroradiol 1999;20:256–258. Masson C, Godefroy O, Leclerc X, Colombani JM, Leys D. Cerebral venous infarction following thrombosis of the draining vein of a venous angioma (developmental abnormality). Cerebrovasc Dis 2000;10:235–238. Vieira Santos A, Saraiva P. Spontaneous isolated nonhaemorrhagic thrombosis in a child with development venous anomaly: case report and review of the literature. Childs Nerv Syst 2006;22:1631–1633. Hammoud D, Beauchamp N, Wityk R, Yousem D. Ischemic complication of a cerebral developmental venous anomaly: case report and review of the literature. J Comput Assist Tomogr 2002;26:633–636.

Neurology 72

January 6, 2009

93

DNM2 CNM mutation in the CMT region. Among the DNM2-related CNM, the phenotype appears intermediate, with an onset at the end of the first decade and a more rapid progression relative to the mild lateonset DNM2-CNM. Case report. The patient is a 34-year-old woman from a nonconsanguineous family from central Africa without history of neuromuscular disorders. She had a normal mental and motor postnatal development with independent ambulation acquired at 13 months. Symptoms started at the age of 7 years with

Figure

difficulty walking and running. At 10 years, she had facial weakness, bilateral ptosis, and a marked weakness in paraspinal, upper, and lower limb muscles. Motor nerve conduction velocities of the left common peroneal (49.4 m/second) and ulnar nerves (53.5 m/second) and latencies were normal for age. Electromyography (EMG) revealed a myopathic pattern without neuropathic signs. From the ages of 10 to 30 years, axial and limb muscle strength deteriorated continuously, but with a more pronounced aggravation between 11 and 15 years. She developed a severe ophthalmoparesis and progressive

Summary of mutated DNM2 amino acids in human diseases and muscle features from the patient

(A) DNM2 is composed of a GTPase domain (GTPase), a middle domain (Middle), a Pleckstrin homology (PH) domain, a GTPase effector domain (GED), and a proline-rich domain (PRD). CNM mutations (amino acids indicated in bold) are located in the middle domain and in the C-terminal part of the PH domain. CMT mutations are located in the N-terminal part of the PH domain. The novel DNM2-CNM (boxed) mutation p.E560K was identified in the protein region involved in CMT. The amino acids were numbered according to the isoform 1 (accession number: NP_001005360) which includes the four amino acids GEIL at positions 516 –519. (B–F) Computer tomography scans of upper and lower limb muscles of the patient at 28 years of age. Axial scanning sections corresponding to (B) ⫽ arm, middle plane; (C) ⫽ forearm; (D) ⫽ pelvic girdle muscles; (E) ⫽ tight, middle plane; and (F) ⫽ legs, middle plane. In (B), muscles of the arm are relatively less affected than the other muscular groups. Posterior compartments of the forearms (C) and thighs (E) are relatively more affected than anterior compartments at same level. Signal in proximal lower limb muscles is hypointense (D). At the level of the legs (F), both anterior and posterior compartments are affected. (G–I) Deltoid muscle biopsy performed at the age of 10 years that shows characteristic CNM histopathologic findings. Representative fields show central nuclei in 37% of fibers (G: hematoxylineosin staining), radial distribution of sarcoplasmic strands in 22% of fibers (H: nicotinamide adenine dinucleotidetetrazolium reductase staining), and predominance and hypotrophy of type 1 fibers (I: ATPase preincubated at pH 9.4 staining). Type 1 fibers represent 98% of fibers. 94

Neurology 72

January 6, 2009

difficulty climbing stairs, frequent falls, and dysphagia. At age 30 years, her maximum distance for walking was 20 meters and muscle CT scan assessment showed a diffuse involvement of limb muscles (figure, B through F). The posterior compartment of the forearms and thighs were relatively more affected than anterior compartments. In the legs, both anterior and posterior compartments were severely affected but the posterior compartment showed more marked abnormalities. At the last examination (34 years), she had severe arm weakness (shoulder antepulsion limited to 50° and abduction to 40°), had recurrent back pain, and required a wheelchair. Deep tendon reflexes were abolished in the four limbs and EMG showed a myopathic pattern without neuropathic signs. The vital capacity was 51% of the expected value at 12 years, 58% at 23 years, 67% at 30 years, and 45% at 34 years, consistent with a restrictive respiratory syndrome. Electrocardiogram and echocardiogram were normal. Serum creatine kinase levels and leukocyte count were in the normal range. Deltoid muscle biopsy at the age of 10 years revealed nuclear centralization, predominance and hypotrophy of type 1 fibers, and radial arrangement of sarcoplasmic strands (figure, G–I). Moderate endomysial fibrosis was observed, without evidence of necrosis or regeneration. A DNA sample was extracted from blood and the DNM2 gene was sequenced. We identified a heterozygous mutation in exon 15. The mutation (c.G1678A) induces the change of the highly conserved glutamate 560 to lysine (p.E560K) located in the PH domain (figure, A). Discussion. We report a novel DNM2 mutation associated with CNM with a topography of muscle involvement similar to the already reported DNM2-CNM patients,7 but with an unusual progressive course. From the ages of 10 to 15 years, she developed severe, generalized muscle weakness and required a wheelchair from age 30 years. Among the DNM2-CNM patients reported until now, the association of a stable restrictive respiratory syndrome with a relatively rapid evolution, compared to the mild late-onset CNM in which loss of ambulation mostly occurs after the 5th decade, is unique. Consequently, our results enlarge the clinical spectrum of the DNM2-CNM, which includes the severe neonatal and the slow progressive adult mild forms, and also intermediate CNM between these two phenotypes. The p.E560K mutation is positioned in the region of the PH domain in which all the CMT mutations were identified.4-6 In particular, the p.K559del

mutation was showed to cause axonal CMT in a patient with nerve conduction anomalies typical of axonal CMT and without evidence of muscular involvement on EMG and muscle biopsy.6 Inversely, in the patient reported here, nerve conduction studies were normal at age 10 years, EMG revealed only a myopathic pattern at 10 and 34 years, and muscle biopsy displayed the characteristic features of CNM. Therefore, the N-terminal part of the PH domain is not specifically linked to CMT but the cause of the tissue-specific phenotype remains to be determined. From INSERM (M.B., J.A.B., B.P., P.G., N.B.R.), U582, Institut de Myologie, Paris; UPMC Univ Paris 06 (B.P., M.B., P.G., N.B.R.), UMR_S582; Departamento de Neurologı´a y Neurocirugı´a (J.A.B.), HCUCH and Instituto de Ciencias Biome´dicas Universidad de Chile, Santiago; and Centre de Re´fe´rence de Pathologie Neuromusculaire Paris-Est (B.E.), AP-HP (M.F., P.G., N.B.R.), and Association Institut de Myologie (AIM) (M.F.), Groupe Hospitalier Pitie´-Salpeˆtrie`re, Paris, France. Supported by Institut National de la Sante´ et de la Recherche Me´dicale (INSERM), the Association Franc¸aise contre les Myopathies (AFM), and the Programme of Collaboration ECOSSECyT (N° A02S02). Jorge A. Bevilacqua was supported by the Programme Alban, the European Union Programme of High Level Scholarships for Latin America, scholarship No. E04E028343CL. Disclosure: The authors report no disclosures. Received April 24, 2008. Accepted in final form July 8, 2008. Address correspondence and reprint requests to Dr. Marc Bitoun, INSERM U582, Institut de Myologie, Groupe Hospitalier Pitie´Salpeˆtrie`re, 75013, Paris, France; [email protected] Copyright © 2009 by AAN Enterprises, Inc. ACKNOWLEDGMENT The authors thank Dr. N. Clarke for advice.

REFERENCES 1.

2.

3.

4.

5.

6.

7.

Jeannet PY, Bassez G, Eymard B, et al. Clinical and histologic findings in autosomal centronuclear myopathy. Neurology 2004;62:1484–1490. Bitoun M, Maugenre S, Jeannet P, et al. Mutations in dynamin 2 cause dominant centronuclear myopathy. Nat Genet 2005;37:1207–1209. Bitoun MP, Bevilacqua JA, Prudhon B, et al. Dynamin 2 mutations cause sporadic centronuclear myopathy with neonatal onset. Ann Neurol 2007;62:666–670. Zu¨chner S, Noureddine M, Kennerson M, et al. Mutations in the pleckstrin homology domain of dynamin 2 cause dominant intermediate Charcot-Marie-Tooth disease. Nat Genet 2005;37:289–294. Fabrizi GM, Ferrarini M, Cavallaro T, et al. Two novel mutations in dynamin-2 cause axonal Charcot-MarieTooth disease. Neurology 2007;69:291–295. Bitoun M, Stojkovic T, Prudhon B, et al. A novel mutation in the dynamin 2 gene in a Charcot-Marie-Tooth type 2 patient: clinical and pathological findings. Neuromuscul Disord 2008;18:334–338. Fischer D, Herasse M, Bitoun M, et al. Characterization of the muscle involvement in dynamin 2 related centronuclear myopathy. Brain 2006;129:1463–1469.

Neurology 72

January 6, 2009

95

M. Wendt, MD J. Wohlrab, MD S. Zierz, MD M. Deschauer, MD

96

EFALIZUMAB-INDUCED ISOLATED CEREBRAL LUPUS-LIKE SYNDROME

Drug-induced lupus erythematosus has been recognized as a side effect of more than 80 drugs since its first description in association with sulfadiazine in 1945.1 Novel bioengineered agents for treatment of autoimmune disorders can also induce lupus-like syndromes. This is especially described for tumor necrosis factor alpha (TNF␣) antagonists.2,3 Efalizumab is an immunosuppressive recombinant humanized IgG1 kappa isotype monoclonal antibody that binds to human CD11a. It is indicated for the treatment of adult patients with chronic moderate to severe plaque type psoriasis.4 Although efalizumab was been used for treatment of refractory subacute cutaneous lupus erythematosus,5 this drug can also induce the cutaneous form of this disease.6 However, a cerebral lupus-like syndrome has not been reported in association with efalizumab. We report a 56-year-old man who was admitted to the hospital because of psychosyndrome and movement disorder. His wife reported a change of his character 2 weeks before. A few days previously he developed uncontrolled movements of all limbs, so that he could not walk alone. There was a history of a severe recalcitrant plaque type psoriasis, which was futilely treated with cyclosporine A, methotrexate, and fumaric acid esters. For 3 months the patient received efalizumab (60 mg subcutaneous once a week). Clinical examination showed an awake patient who was incompletely orientated to time, place, person, and situation. Memory was severely disturbed. There were psychomotor retardation and confabulations. Generalized myoclonia by activation made the patient unable to stand without help. Cranial nerves, sensory examination, and tendon reflexes were normal. Babinski sign was negative. There was a normochromatic and normocytic anemia with hemoglobin of 4.9 mmol/L (normal 8.7– 11.2), erythrocytes of 2.64 Tpt/L (normal 4.60 – 6.20), and a hematocrit of 0.23% (normal 0.42– 0.52). The combination of increased consumption of iron (transferrin 1.5 g/L, normal 2.0–3.6 and ferritin 713.0 ng/mL, normal 28.0 –365.0) caused by inflammation together with low vitamin B12 levels (128 pmol/L, normal 133– 675) might explain the observed normochromatic and normocytic anemia. Coombs test was negative, arguing against autoimmune hemolytic anemia. Blood sedimentation rate (BSR) was 60/ 105, leukocytes were 3.66 Gpt/L (normal 3.80 – 9.80), and C-reactive protein was 16.2 mg/L (normal ⬍5). Complement factor C3 was 0.63 g/L (normal 0.90 –1.80) and C4 was normal. ANA titer was higher than 1:640, with a homogenous pattern. AntidsDNA antibodies were 383.70 U/mL (normal Neurology 72

January 6, 2009

⬍30.00) and anti-histone antibodies 12.80 U/mL (normal ⬍1.00). Antineuronal antibodies (anti-Yo, anti-Hu, anti-Ri), anti-thyroid antibodies, ANCA, ammonia, serum creatinine, electrolytes, and liver enzymes were normal. Urine analysis showed no proteinuria. CSF revealed a slight impairment of blood– brain barrier and elevated protein of 1,300 mg/L (normal 200 – 400). There was no intrathecal synthesis of immunoglobulin and oligoclonal bands were negative. Cell count, glucose, lactate, protein 14-3-3, tauprotein, ␤-amyloid, and NSE were unremarkable. MRI of the brain at admission and 2 weeks later was normal. EEG revealed generalized theta-waves but no epileptic discharges or triphasic waves. The patient showed no clinical abnormalities of cardiac or pulmonary function. ECG and chest X-ray were normal. Gastroscopy, coloscopy, abdominal sonography, and skin biopsy were unremarkable. Suspecting an autoimmunologic disease as a side effect of efalizumab, this therapy was terminated and prednisolone (100 mg daily) was administered. During the following days, the clinical condition improved. He became oriented to all qualities. The movement disorder was no longer detectable and he walked unaided. By reduction of prednisolone to 40 mg daily, within 1 month the clinical findings remained stable. The patient only complained about a slightly disturbed memory. At that time ANA titer was 1:320, dsDNA 213.40 U/mL, hemoglobin 7.1 mmol/L, and BSR 20/43. EEG showed alpha-rhythm without any focal signs. After 14 months, the patient showed no clinical abnormalities and was able to work. Prednisolone was reduced to 10 mg and mycophenolate (2,000 mg) was introduced. Acute psychosyndrome and movement disorder that is reversible upon therapy with prednisolone can be a manifestation of different autoimmune disorders. The patient had the typical laboratory constellation of lupus erythematosus with dsDNA antibodies and elevated BSR. There was no evidence for other subacute diseases presenting with movement disorder and psychiatric symptoms, such as Hashimoto encephalopathy, CreutzfeldtJakob disease, or other metabolic, inflammatory, or paraneoplastic diseases. The clinical symptoms together with antibody findings can be interpreted as an isolated cerebral lupus-like syndrome without multisystemic involvement. Although it cannot entirely be excluded that the disease occurred spontaneously, the close temporal association with efalizumab treatment suggests a drug-induced lupus-like syndrome. The anti-histone antibodies also support the view that this case was drug-induced.1 Efalizumab-induced cutaneous lupus erythematosus has already been described.6 This re-

port shows that efalizumab might also induce an isolated cerebral lupus-like syndrome. From the Departments of Neurology (M.W., S.Z., M.D.) and Dermatology (J.W.), Martin Luther University of Halle-Wittenberg, Germany. Disclosure: The authors report no disclosures. Received April 25, 2008. Accepted in final form August 5, 2008. Address correspondence and reprint requests to Dr. Matthias Wendt, Department of Neurology, Martin Luther University of HalleWittenberg, Ernst-Grube-Str. 40, 06097 Halle (Saale), Germany; [email protected] Copyright © 2009 by AAN Enterprises, Inc. 1.

2. 3.

4.

5.

6.

Vasoo S. Drug-induced lupus: an update. Lupus 2006;15: 757–761.

Callen JP. Complications and adverse reactions in the use of newer biologic agents. Semin Cutan Med Surg 2007;26:6–14. De Bandt M, Sibilia J, Le Loet X, et al. Systemic lupus erythematosus induced by anti-tumour necrosis factor alpha therapy: a French national survey. Arthritis Res Ther 2005;7:R545–R551. Kerns MJ, Graves JE, Smith DI, Heffernan MP. Off-label uses of biologic agents in dermatology: a 2006 update. Semin Cutan Med Surg 2006;25:226–240. Clayton TH, Ogden S, Goodield M. Treatment of refractory subacute cutaneous lupus erythematosus with efalizumab. J Am Acad Dematol 2006;54:892–895. Bentley DD, Graves JE, Smith DI, Hefernan MP. Efalizumab-induced subacute cutaneous lupus erythematosus. J Am Acad Dematol 2006;54:S242–243.

www.neurology.org Offers Important Information to Patients and Their Families The Neurology® Patient Page provides: • A critical review of ground-breaking discoveries in neurologic research that are written especially for patients and their families • Up-to-date patient information about many neurologic diseases • Links to additional information resources for neurologic patients All Neurology Patient Page articles can be easily downloaded and printed, and may be reproduced to distribute for educational purposes. Click on the Patient Page icon on the home page (www. neurology.org) for a complete index of Patient Pages.

Activate Your Online Subscription At www.neurology.org, subscribers can now access the full text of the current issue of Neurology® and back issues. Select the “Login instructions” link that is provided on the Help screen. Here you will be guided through a step-by-step activation process. Neurology® online offers: • e-Pub ahead of print • Extensive search capabilities • Complete online Information for Authors • Access to Journal content in both Adobe Acrobat PDF and HTML formats • Links to PubMed • Examinations on designated articles for CME credit • Resident & Fellow section • Patient Page • Access to in-depth supplementary scientific data

Neurology 72

January 6, 2009

97

Clinical/Scientific Notes

Sashank Prasad, MD Robert W. Hurst, MD Scott E. Kasner, MD

POSTPARTUM THROMBOSIS OF A DEVELOPMENTAL VENOUS ANOMALY

Figure

MRI and angiography findings

Developmental venous anomaly (DVA) is a common congenital vascular abnormality that typically has a benign natural history. The lesion likely occurs after atresia or thrombosis of normal venous structures, leading to compensatory retention of embryologic medullary venules.1,2 These venules form an umbrella- shaped arrangement (caput medusae) and cluster into a large central vein that drains into the deep or superficial venous system.1,2 Spontaneous thrombosis of the central vein of a DVA can rarely occur, and lead to symptomatic nonhemorrhagic venous infarction.2-7 Most reported cases of DVA thrombosis demonstrate no underlying predisposition.2-6 One report of nonhemorrhagic venous infarction attributes thrombosis to hypercoagulability induced by puerperium, oral contraceptive use, and smoking.7 We report a case of DVA thrombosis occurring in a postpartum patient on hormonal contraception.

Supplemental data at www.neurology.org

92

Case report. A 16-year-old G1P1 woman presented after three brief simple motor seizures involving the right arm and face occurring over 3 days. She denied persistent symptoms. After the first seizure, she had presented to another hospital and was treated with phenytoin, but did not undergo any neuroimaging studies. Four years previously, she had three episodes of right face, arm, and leg shaking, lasting 2 minutes, without altered consciousness. A routine EEG revealed occipital slowing, but no epileptiform discharges. Brain MRI revealed multiple small vessels draining into an enlarged vein in the left frontal lobe, representing a venous angioma (figure, A). The patient was lost to follow-up, and no antiepileptic agents were started. Three weeks prior, in the 40th week of pregnancy, she was presumptively diagnosed with mild preeclampsia on the basis of elevated blood pressure (146/96 mm Hg) but without proteinuria or edema. She had a 20minute episode of right face and arm shaking with secondary generalization, which was presumed to be an eclamptic seizure. She was treated with IV magnesium and diazepam. A head CT was reportedly negative. She Neurology 72

January 6, 2009

Gadolinium-enhanced T1-weighted MRI revealed left frontal developmental venous anomaly (A, June 2003; B, September 2007, thrombosis within draining vein, with absent flow-void; C, November 2007, resolution of thrombosis). Conventional angiogram (D, left internal carotid artery injection, oblique view) revealed thrombosis of the draining vein (red arrow) of a DVA (yellow arrow). There is delayed emptying of the medullary veins into the late venous phase. See video on the Neurology® Web site at www.neurology.org.

underwent emergent Cesarean section. She recovered fully, and no additional studies were performed. The patient had no other medical illnesses, and there was no relevant family history. Immediately after her delivery, she had received the contraceptive

M. Bitoun, PhD J.A. Bevilacqua, MD, PhD B. Eymard, MD, PhD B. Prudhon, MSc M. Fardeau, MD P. Guicheney, PhD N.B. Romero, MD, PhD

depot medroxyprogesterone acetate (DMPA). She was on no other medications. She denied smoking. The entire examination was normal, including mental status, cranial nerves, strength, sensation, coordination, reflexes, and gait. Noncontrast CT scan of the head revealed a region of hyperdensity within the left frontal lobe. Brain MRI revealed a partially thrombosed venous angioma with surrounding areas of swelling and edema (figure, B). Diffusion-weighted imaging revealed no evidence of restricted diffusion. Gradient echo sequences showed susceptibility artifact within the venous angioma and many of its periventricular branches. Postgadolinium images demonstrated dilated medullary veins and hyperintensity within an enlarged superficial draining vein. Digital subtraction angiography was performed, and injection of the left common carotid artery demonstrated a tangle of small vessels in the posterior left frontal lobe filling during the late venous phase, compatible with a venous angioma (figure, D; video). Emptying of the medullary veins was delayed, suggesting thrombosis of the major draining vein. No aneurysm or arteriovenous malformation was noted and the dural venous sinuses were patent. Blood cell counts and coagulation profiles were normal. Protein C and S levels, antithrombin III level, and homocysteine level were normal. Activated protein C resistance was not present. Antinuclear antibody, anticardiolipin antibody, anti ␤2-glycoprotein antibody, factor V Leiden mutation, and prothrombin gene mutation were negative. The patient was treated with warfarin (goal INR 2.0 –3.0) and levetiracetam. At 3-month follow-up, she reported no further seizures. Repeat MRI and MRA demonstrated resolution of thrombosis within the DVA (figure, C). Warfarin was discontinued. At 6-month follow-up, levetiracetam was discontinued.

sinus thrombosis. Management of this condition should include evaluation for inherited thrombophilia and short-term anticoagulation. Given the relatively benign natural history of DVAs, the risks of hemorrhage during the course of short-term anticoagulation are expected to be minimal, while the benefits of anticoagulation for cerebral venous sinus thrombosis may be substantial. Surgical resection of a DVA is not recommended since the vessel may be the only venous drainage for the surrounding brain parenchyma.1

Discussion. Although DVAs are considered to be relatively benign, there is growing recognition that they may cause venous infarction or hemorrhage. Our patient demonstrates that thrombosis of a DVA may occur in the hypercoagulable state induced by puerperium and hormonal contraception, and possibly preeclampsia, which are risk factors for venous

6.

A NEW CENTRONUCLEAR MYOPATHY PHENOTYPE DUE TO A NOVEL DYNAMIN 2 MUTATION

identified in CNM.2,3 Mutations in the middle domain of the protein are mostly associated with the slowly progressive mild late-onset CNM,2 while mutations in the C-terminal part of the Pleckstrin homology (PH) domain cause a more severe neonatal phenotype.3 In addition, mutations in the N-terminal part of PH domain have been reported in intermediate and axonal CharcotMarie-Tooth disease (CMT).4-6 Here, we report a novel

Autosomal dominant centronuclear myopathy (CNM) is a rare congenital myopathy mostly characterized by delayed motor milestones, slowly progressive muscle weakness, and bilateral ptosis.1 Mutations in the DNM2 gene encoding dynamin 2 (DNM2), a large GTPase involved in membrane trafficking, have been

From the Departments of Neurology (S.P., S.E.K.) and Radiology (R.W.H.), Hospital of the University of Pennsylvania, Philadelphia. Disclosure: The authors report no disclosures. Received March 28, 2008. Accepted in final form July 3, 2008. Address correspondence and reprint requests to Dr. Sashank Prasad, Department of Neurology, Hospital of the University of Pennsylvania, 3W Gates Bldg., 3600 Spruce Street, Philadelphia, PA 19104; [email protected] Copyright © 2009 by AAN Enterprises, Inc. 1.

2.

3.

4.

5.

7.

Agazzi S, Regli L, Uske A, Maeder P, de Tribolet N. Developmental venous anomaly with an arteriovenous shunt and a thrombotic complication: case report. J Neurosurg 2001;94:533–537. Peltier J, Toussaint P, Desenclos C, Le Gars D, Deramond H. Cerebral venous angioma of the pons complicated by nonhemorrhagic infarction: case report. J Neurosurg 2004;101:690–693. Lai PH, Chen PC, Pan HB, Yang CF. Venous infarction from a venous angioma occurring after thrombosis of a drainage vein. AJR Am J Roentgenol 1999;172:1698– 1699. Konan AV, Raymond J, Bourgouin P, Lesage J, Milot G, Roy D. Cerebellar infarct caused by spontaneous thrombosis of a developmental venous anomaly of the posterior fossa. AJNR Am J Neuroradiol 1999;20:256–258. Masson C, Godefroy O, Leclerc X, Colombani JM, Leys D. Cerebral venous infarction following thrombosis of the draining vein of a venous angioma (developmental abnormality). Cerebrovasc Dis 2000;10:235–238. Vieira Santos A, Saraiva P. Spontaneous isolated nonhaemorrhagic thrombosis in a child with development venous anomaly: case report and review of the literature. Childs Nerv Syst 2006;22:1631–1633. Hammoud D, Beauchamp N, Wityk R, Yousem D. Ischemic complication of a cerebral developmental venous anomaly: case report and review of the literature. J Comput Assist Tomogr 2002;26:633–636.

Neurology 72

January 6, 2009

93

DNM2 CNM mutation in the CMT region. Among the DNM2-related CNM, the phenotype appears intermediate, with an onset at the end of the first decade and a more rapid progression relative to the mild lateonset DNM2-CNM. Case report. The patient is a 34-year-old woman from a nonconsanguineous family from central Africa without history of neuromuscular disorders. She had a normal mental and motor postnatal development with independent ambulation acquired at 13 months. Symptoms started at the age of 7 years with

Figure

difficulty walking and running. At 10 years, she had facial weakness, bilateral ptosis, and a marked weakness in paraspinal, upper, and lower limb muscles. Motor nerve conduction velocities of the left common peroneal (49.4 m/second) and ulnar nerves (53.5 m/second) and latencies were normal for age. Electromyography (EMG) revealed a myopathic pattern without neuropathic signs. From the ages of 10 to 30 years, axial and limb muscle strength deteriorated continuously, but with a more pronounced aggravation between 11 and 15 years. She developed a severe ophthalmoparesis and progressive

Summary of mutated DNM2 amino acids in human diseases and muscle features from the patient

(A) DNM2 is composed of a GTPase domain (GTPase), a middle domain (Middle), a Pleckstrin homology (PH) domain, a GTPase effector domain (GED), and a proline-rich domain (PRD). CNM mutations (amino acids indicated in bold) are located in the middle domain and in the C-terminal part of the PH domain. CMT mutations are located in the N-terminal part of the PH domain. The novel DNM2-CNM (boxed) mutation p.E560K was identified in the protein region involved in CMT. The amino acids were numbered according to the isoform 1 (accession number: NP_001005360) which includes the four amino acids GEIL at positions 516 –519. (B–F) Computer tomography scans of upper and lower limb muscles of the patient at 28 years of age. Axial scanning sections corresponding to (B) ⫽ arm, middle plane; (C) ⫽ forearm; (D) ⫽ pelvic girdle muscles; (E) ⫽ tight, middle plane; and (F) ⫽ legs, middle plane. In (B), muscles of the arm are relatively less affected than the other muscular groups. Posterior compartments of the forearms (C) and thighs (E) are relatively more affected than anterior compartments at same level. Signal in proximal lower limb muscles is hypointense (D). At the level of the legs (F), both anterior and posterior compartments are affected. (G–I) Deltoid muscle biopsy performed at the age of 10 years that shows characteristic CNM histopathologic findings. Representative fields show central nuclei in 37% of fibers (G: hematoxylineosin staining), radial distribution of sarcoplasmic strands in 22% of fibers (H: nicotinamide adenine dinucleotidetetrazolium reductase staining), and predominance and hypotrophy of type 1 fibers (I: ATPase preincubated at pH 9.4 staining). Type 1 fibers represent 98% of fibers. 94

Neurology 72

January 6, 2009

difficulty climbing stairs, frequent falls, and dysphagia. At age 30 years, her maximum distance for walking was 20 meters and muscle CT scan assessment showed a diffuse involvement of limb muscles (figure, B through F). The posterior compartment of the forearms and thighs were relatively more affected than anterior compartments. In the legs, both anterior and posterior compartments were severely affected but the posterior compartment showed more marked abnormalities. At the last examination (34 years), she had severe arm weakness (shoulder antepulsion limited to 50° and abduction to 40°), had recurrent back pain, and required a wheelchair. Deep tendon reflexes were abolished in the four limbs and EMG showed a myopathic pattern without neuropathic signs. The vital capacity was 51% of the expected value at 12 years, 58% at 23 years, 67% at 30 years, and 45% at 34 years, consistent with a restrictive respiratory syndrome. Electrocardiogram and echocardiogram were normal. Serum creatine kinase levels and leukocyte count were in the normal range. Deltoid muscle biopsy at the age of 10 years revealed nuclear centralization, predominance and hypotrophy of type 1 fibers, and radial arrangement of sarcoplasmic strands (figure, G–I). Moderate endomysial fibrosis was observed, without evidence of necrosis or regeneration. A DNA sample was extracted from blood and the DNM2 gene was sequenced. We identified a heterozygous mutation in exon 15. The mutation (c.G1678A) induces the change of the highly conserved glutamate 560 to lysine (p.E560K) located in the PH domain (figure, A). Discussion. We report a novel DNM2 mutation associated with CNM with a topography of muscle involvement similar to the already reported DNM2-CNM patients,7 but with an unusual progressive course. From the ages of 10 to 15 years, she developed severe, generalized muscle weakness and required a wheelchair from age 30 years. Among the DNM2-CNM patients reported until now, the association of a stable restrictive respiratory syndrome with a relatively rapid evolution, compared to the mild late-onset CNM in which loss of ambulation mostly occurs after the 5th decade, is unique. Consequently, our results enlarge the clinical spectrum of the DNM2-CNM, which includes the severe neonatal and the slow progressive adult mild forms, and also intermediate CNM between these two phenotypes. The p.E560K mutation is positioned in the region of the PH domain in which all the CMT mutations were identified.4-6 In particular, the p.K559del

mutation was showed to cause axonal CMT in a patient with nerve conduction anomalies typical of axonal CMT and without evidence of muscular involvement on EMG and muscle biopsy.6 Inversely, in the patient reported here, nerve conduction studies were normal at age 10 years, EMG revealed only a myopathic pattern at 10 and 34 years, and muscle biopsy displayed the characteristic features of CNM. Therefore, the N-terminal part of the PH domain is not specifically linked to CMT but the cause of the tissue-specific phenotype remains to be determined. From INSERM (M.B., J.A.B., B.P., P.G., N.B.R.), U582, Institut de Myologie, Paris; UPMC Univ Paris 06 (B.P., M.B., P.G., N.B.R.), UMR_S582; Departamento de Neurologı´a y Neurocirugı´a (J.A.B.), HCUCH and Instituto de Ciencias Biome´dicas Universidad de Chile, Santiago; and Centre de Re´fe´rence de Pathologie Neuromusculaire Paris-Est (B.E.), AP-HP (M.F., P.G., N.B.R.), and Association Institut de Myologie (AIM) (M.F.), Groupe Hospitalier Pitie´-Salpeˆtrie`re, Paris, France. Supported by Institut National de la Sante´ et de la Recherche Me´dicale (INSERM), the Association Franc¸aise contre les Myopathies (AFM), and the Programme of Collaboration ECOSSECyT (N° A02S02). Jorge A. Bevilacqua was supported by the Programme Alban, the European Union Programme of High Level Scholarships for Latin America, scholarship No. E04E028343CL. Disclosure: The authors report no disclosures. Received April 24, 2008. Accepted in final form July 8, 2008. Address correspondence and reprint requests to Dr. Marc Bitoun, INSERM U582, Institut de Myologie, Groupe Hospitalier Pitie´Salpeˆtrie`re, 75013, Paris, France; [email protected] Copyright © 2009 by AAN Enterprises, Inc. ACKNOWLEDGMENT The authors thank Dr. N. Clarke for advice.

REFERENCES 1.

2.

3.

4.

5.

6.

7.

Jeannet PY, Bassez G, Eymard B, et al. Clinical and histologic findings in autosomal centronuclear myopathy. Neurology 2004;62:1484–1490. Bitoun M, Maugenre S, Jeannet P, et al. Mutations in dynamin 2 cause dominant centronuclear myopathy. Nat Genet 2005;37:1207–1209. Bitoun MP, Bevilacqua JA, Prudhon B, et al. Dynamin 2 mutations cause sporadic centronuclear myopathy with neonatal onset. Ann Neurol 2007;62:666–670. Zu¨chner S, Noureddine M, Kennerson M, et al. Mutations in the pleckstrin homology domain of dynamin 2 cause dominant intermediate Charcot-Marie-Tooth disease. Nat Genet 2005;37:289–294. Fabrizi GM, Ferrarini M, Cavallaro T, et al. Two novel mutations in dynamin-2 cause axonal Charcot-MarieTooth disease. Neurology 2007;69:291–295. Bitoun M, Stojkovic T, Prudhon B, et al. A novel mutation in the dynamin 2 gene in a Charcot-Marie-Tooth type 2 patient: clinical and pathological findings. Neuromuscul Disord 2008;18:334–338. Fischer D, Herasse M, Bitoun M, et al. Characterization of the muscle involvement in dynamin 2 related centronuclear myopathy. Brain 2006;129:1463–1469.

Neurology 72

January 6, 2009

95

M. Wendt, MD J. Wohlrab, MD S. Zierz, MD M. Deschauer, MD

96

EFALIZUMAB-INDUCED ISOLATED CEREBRAL LUPUS-LIKE SYNDROME

Drug-induced lupus erythematosus has been recognized as a side effect of more than 80 drugs since its first description in association with sulfadiazine in 1945.1 Novel bioengineered agents for treatment of autoimmune disorders can also induce lupus-like syndromes. This is especially described for tumor necrosis factor alpha (TNF␣) antagonists.2,3 Efalizumab is an immunosuppressive recombinant humanized IgG1 kappa isotype monoclonal antibody that binds to human CD11a. It is indicated for the treatment of adult patients with chronic moderate to severe plaque type psoriasis.4 Although efalizumab was been used for treatment of refractory subacute cutaneous lupus erythematosus,5 this drug can also induce the cutaneous form of this disease.6 However, a cerebral lupus-like syndrome has not been reported in association with efalizumab. We report a 56-year-old man who was admitted to the hospital because of psychosyndrome and movement disorder. His wife reported a change of his character 2 weeks before. A few days previously he developed uncontrolled movements of all limbs, so that he could not walk alone. There was a history of a severe recalcitrant plaque type psoriasis, which was futilely treated with cyclosporine A, methotrexate, and fumaric acid esters. For 3 months the patient received efalizumab (60 mg subcutaneous once a week). Clinical examination showed an awake patient who was incompletely orientated to time, place, person, and situation. Memory was severely disturbed. There were psychomotor retardation and confabulations. Generalized myoclonia by activation made the patient unable to stand without help. Cranial nerves, sensory examination, and tendon reflexes were normal. Babinski sign was negative. There was a normochromatic and normocytic anemia with hemoglobin of 4.9 mmol/L (normal 8.7– 11.2), erythrocytes of 2.64 Tpt/L (normal 4.60 – 6.20), and a hematocrit of 0.23% (normal 0.42– 0.52). The combination of increased consumption of iron (transferrin 1.5 g/L, normal 2.0–3.6 and ferritin 713.0 ng/mL, normal 28.0 –365.0) caused by inflammation together with low vitamin B12 levels (128 pmol/L, normal 133– 675) might explain the observed normochromatic and normocytic anemia. Coombs test was negative, arguing against autoimmune hemolytic anemia. Blood sedimentation rate (BSR) was 60/ 105, leukocytes were 3.66 Gpt/L (normal 3.80 – 9.80), and C-reactive protein was 16.2 mg/L (normal ⬍5). Complement factor C3 was 0.63 g/L (normal 0.90 –1.80) and C4 was normal. ANA titer was higher than 1:640, with a homogenous pattern. AntidsDNA antibodies were 383.70 U/mL (normal Neurology 72

January 6, 2009

⬍30.00) and anti-histone antibodies 12.80 U/mL (normal ⬍1.00). Antineuronal antibodies (anti-Yo, anti-Hu, anti-Ri), anti-thyroid antibodies, ANCA, ammonia, serum creatinine, electrolytes, and liver enzymes were normal. Urine analysis showed no proteinuria. CSF revealed a slight impairment of blood– brain barrier and elevated protein of 1,300 mg/L (normal 200 – 400). There was no intrathecal synthesis of immunoglobulin and oligoclonal bands were negative. Cell count, glucose, lactate, protein 14-3-3, tauprotein, ␤-amyloid, and NSE were unremarkable. MRI of the brain at admission and 2 weeks later was normal. EEG revealed generalized theta-waves but no epileptic discharges or triphasic waves. The patient showed no clinical abnormalities of cardiac or pulmonary function. ECG and chest X-ray were normal. Gastroscopy, coloscopy, abdominal sonography, and skin biopsy were unremarkable. Suspecting an autoimmunologic disease as a side effect of efalizumab, this therapy was terminated and prednisolone (100 mg daily) was administered. During the following days, the clinical condition improved. He became oriented to all qualities. The movement disorder was no longer detectable and he walked unaided. By reduction of prednisolone to 40 mg daily, within 1 month the clinical findings remained stable. The patient only complained about a slightly disturbed memory. At that time ANA titer was 1:320, dsDNA 213.40 U/mL, hemoglobin 7.1 mmol/L, and BSR 20/43. EEG showed alpha-rhythm without any focal signs. After 14 months, the patient showed no clinical abnormalities and was able to work. Prednisolone was reduced to 10 mg and mycophenolate (2,000 mg) was introduced. Acute psychosyndrome and movement disorder that is reversible upon therapy with prednisolone can be a manifestation of different autoimmune disorders. The patient had the typical laboratory constellation of lupus erythematosus with dsDNA antibodies and elevated BSR. There was no evidence for other subacute diseases presenting with movement disorder and psychiatric symptoms, such as Hashimoto encephalopathy, CreutzfeldtJakob disease, or other metabolic, inflammatory, or paraneoplastic diseases. The clinical symptoms together with antibody findings can be interpreted as an isolated cerebral lupus-like syndrome without multisystemic involvement. Although it cannot entirely be excluded that the disease occurred spontaneously, the close temporal association with efalizumab treatment suggests a drug-induced lupus-like syndrome. The anti-histone antibodies also support the view that this case was drug-induced.1 Efalizumab-induced cutaneous lupus erythematosus has already been described.6 This re-

port shows that efalizumab might also induce an isolated cerebral lupus-like syndrome. From the Departments of Neurology (M.W., S.Z., M.D.) and Dermatology (J.W.), Martin Luther University of Halle-Wittenberg, Germany. Disclosure: The authors report no disclosures. Received April 25, 2008. Accepted in final form August 5, 2008. Address correspondence and reprint requests to Dr. Matthias Wendt, Department of Neurology, Martin Luther University of HalleWittenberg, Ernst-Grube-Str. 40, 06097 Halle (Saale), Germany; [email protected] Copyright © 2009 by AAN Enterprises, Inc. 1.

2. 3.

4.

5.

6.

Vasoo S. Drug-induced lupus: an update. Lupus 2006;15: 757–761.

Callen JP. Complications and adverse reactions in the use of newer biologic agents. Semin Cutan Med Surg 2007;26:6–14. De Bandt M, Sibilia J, Le Loet X, et al. Systemic lupus erythematosus induced by anti-tumour necrosis factor alpha therapy: a French national survey. Arthritis Res Ther 2005;7:R545–R551. Kerns MJ, Graves JE, Smith DI, Heffernan MP. Off-label uses of biologic agents in dermatology: a 2006 update. Semin Cutan Med Surg 2006;25:226–240. Clayton TH, Ogden S, Goodield M. Treatment of refractory subacute cutaneous lupus erythematosus with efalizumab. J Am Acad Dematol 2006;54:892–895. Bentley DD, Graves JE, Smith DI, Hefernan MP. Efalizumab-induced subacute cutaneous lupus erythematosus. J Am Acad Dematol 2006;54:S242–243.

www.neurology.org Offers Important Information to Patients and Their Families The Neurology® Patient Page provides: • A critical review of ground-breaking discoveries in neurologic research that are written especially for patients and their families • Up-to-date patient information about many neurologic diseases • Links to additional information resources for neurologic patients All Neurology Patient Page articles can be easily downloaded and printed, and may be reproduced to distribute for educational purposes. Click on the Patient Page icon on the home page (www. neurology.org) for a complete index of Patient Pages.

Activate Your Online Subscription At www.neurology.org, subscribers can now access the full text of the current issue of Neurology® and back issues. Select the “Login instructions” link that is provided on the Help screen. Here you will be guided through a step-by-step activation process. Neurology® online offers: • e-Pub ahead of print • Extensive search capabilities • Complete online Information for Authors • Access to Journal content in both Adobe Acrobat PDF and HTML formats • Links to PubMed • Examinations on designated articles for CME credit • Resident & Fellow section • Patient Page • Access to in-depth supplementary scientific data

Neurology 72

January 6, 2009

97

Clinical/Scientific Notes

Sashank Prasad, MD Robert W. Hurst, MD Scott E. Kasner, MD

POSTPARTUM THROMBOSIS OF A DEVELOPMENTAL VENOUS ANOMALY

Figure

MRI and angiography findings

Developmental venous anomaly (DVA) is a common congenital vascular abnormality that typically has a benign natural history. The lesion likely occurs after atresia or thrombosis of normal venous structures, leading to compensatory retention of embryologic medullary venules.1,2 These venules form an umbrella- shaped arrangement (caput medusae) and cluster into a large central vein that drains into the deep or superficial venous system.1,2 Spontaneous thrombosis of the central vein of a DVA can rarely occur, and lead to symptomatic nonhemorrhagic venous infarction.2-7 Most reported cases of DVA thrombosis demonstrate no underlying predisposition.2-6 One report of nonhemorrhagic venous infarction attributes thrombosis to hypercoagulability induced by puerperium, oral contraceptive use, and smoking.7 We report a case of DVA thrombosis occurring in a postpartum patient on hormonal contraception.

Supplemental data at www.neurology.org

92

Case report. A 16-year-old G1P1 woman presented after three brief simple motor seizures involving the right arm and face occurring over 3 days. She denied persistent symptoms. After the first seizure, she had presented to another hospital and was treated with phenytoin, but did not undergo any neuroimaging studies. Four years previously, she had three episodes of right face, arm, and leg shaking, lasting 2 minutes, without altered consciousness. A routine EEG revealed occipital slowing, but no epileptiform discharges. Brain MRI revealed multiple small vessels draining into an enlarged vein in the left frontal lobe, representing a venous angioma (figure, A). The patient was lost to follow-up, and no antiepileptic agents were started. Three weeks prior, in the 40th week of pregnancy, she was presumptively diagnosed with mild preeclampsia on the basis of elevated blood pressure (146/96 mm Hg) but without proteinuria or edema. She had a 20minute episode of right face and arm shaking with secondary generalization, which was presumed to be an eclamptic seizure. She was treated with IV magnesium and diazepam. A head CT was reportedly negative. She Neurology 72

January 6, 2009

Gadolinium-enhanced T1-weighted MRI revealed left frontal developmental venous anomaly (A, June 2003; B, September 2007, thrombosis within draining vein, with absent flow-void; C, November 2007, resolution of thrombosis). Conventional angiogram (D, left internal carotid artery injection, oblique view) revealed thrombosis of the draining vein (red arrow) of a DVA (yellow arrow). There is delayed emptying of the medullary veins into the late venous phase. See video on the Neurology® Web site at www.neurology.org.

underwent emergent Cesarean section. She recovered fully, and no additional studies were performed. The patient had no other medical illnesses, and there was no relevant family history. Immediately after her delivery, she had received the contraceptive

M. Bitoun, PhD J.A. Bevilacqua, MD, PhD B. Eymard, MD, PhD B. Prudhon, MSc M. Fardeau, MD P. Guicheney, PhD N.B. Romero, MD, PhD

depot medroxyprogesterone acetate (DMPA). She was on no other medications. She denied smoking. The entire examination was normal, including mental status, cranial nerves, strength, sensation, coordination, reflexes, and gait. Noncontrast CT scan of the head revealed a region of hyperdensity within the left frontal lobe. Brain MRI revealed a partially thrombosed venous angioma with surrounding areas of swelling and edema (figure, B). Diffusion-weighted imaging revealed no evidence of restricted diffusion. Gradient echo sequences showed susceptibility artifact within the venous angioma and many of its periventricular branches. Postgadolinium images demonstrated dilated medullary veins and hyperintensity within an enlarged superficial draining vein. Digital subtraction angiography was performed, and injection of the left common carotid artery demonstrated a tangle of small vessels in the posterior left frontal lobe filling during the late venous phase, compatible with a venous angioma (figure, D; video). Emptying of the medullary veins was delayed, suggesting thrombosis of the major draining vein. No aneurysm or arteriovenous malformation was noted and the dural venous sinuses were patent. Blood cell counts and coagulation profiles were normal. Protein C and S levels, antithrombin III level, and homocysteine level were normal. Activated protein C resistance was not present. Antinuclear antibody, anticardiolipin antibody, anti ␤2-glycoprotein antibody, factor V Leiden mutation, and prothrombin gene mutation were negative. The patient was treated with warfarin (goal INR 2.0 –3.0) and levetiracetam. At 3-month follow-up, she reported no further seizures. Repeat MRI and MRA demonstrated resolution of thrombosis within the DVA (figure, C). Warfarin was discontinued. At 6-month follow-up, levetiracetam was discontinued.

sinus thrombosis. Management of this condition should include evaluation for inherited thrombophilia and short-term anticoagulation. Given the relatively benign natural history of DVAs, the risks of hemorrhage during the course of short-term anticoagulation are expected to be minimal, while the benefits of anticoagulation for cerebral venous sinus thrombosis may be substantial. Surgical resection of a DVA is not recommended since the vessel may be the only venous drainage for the surrounding brain parenchyma.1

Discussion. Although DVAs are considered to be relatively benign, there is growing recognition that they may cause venous infarction or hemorrhage. Our patient demonstrates that thrombosis of a DVA may occur in the hypercoagulable state induced by puerperium and hormonal contraception, and possibly preeclampsia, which are risk factors for venous

6.

A NEW CENTRONUCLEAR MYOPATHY PHENOTYPE DUE TO A NOVEL DYNAMIN 2 MUTATION

identified in CNM.2,3 Mutations in the middle domain of the protein are mostly associated with the slowly progressive mild late-onset CNM,2 while mutations in the C-terminal part of the Pleckstrin homology (PH) domain cause a more severe neonatal phenotype.3 In addition, mutations in the N-terminal part of PH domain have been reported in intermediate and axonal CharcotMarie-Tooth disease (CMT).4-6 Here, we report a novel

Autosomal dominant centronuclear myopathy (CNM) is a rare congenital myopathy mostly characterized by delayed motor milestones, slowly progressive muscle weakness, and bilateral ptosis.1 Mutations in the DNM2 gene encoding dynamin 2 (DNM2), a large GTPase involved in membrane trafficking, have been

From the Departments of Neurology (S.P., S.E.K.) and Radiology (R.W.H.), Hospital of the University of Pennsylvania, Philadelphia. Disclosure: The authors report no disclosures. Received March 28, 2008. Accepted in final form July 3, 2008. Address correspondence and reprint requests to Dr. Sashank Prasad, Department of Neurology, Hospital of the University of Pennsylvania, 3W Gates Bldg., 3600 Spruce Street, Philadelphia, PA 19104; [email protected] Copyright © 2009 by AAN Enterprises, Inc. 1.

2.

3.

4.

5.

7.

Agazzi S, Regli L, Uske A, Maeder P, de Tribolet N. Developmental venous anomaly with an arteriovenous shunt and a thrombotic complication: case report. J Neurosurg 2001;94:533–537. Peltier J, Toussaint P, Desenclos C, Le Gars D, Deramond H. Cerebral venous angioma of the pons complicated by nonhemorrhagic infarction: case report. J Neurosurg 2004;101:690–693. Lai PH, Chen PC, Pan HB, Yang CF. Venous infarction from a venous angioma occurring after thrombosis of a drainage vein. AJR Am J Roentgenol 1999;172:1698– 1699. Konan AV, Raymond J, Bourgouin P, Lesage J, Milot G, Roy D. Cerebellar infarct caused by spontaneous thrombosis of a developmental venous anomaly of the posterior fossa. AJNR Am J Neuroradiol 1999;20:256–258. Masson C, Godefroy O, Leclerc X, Colombani JM, Leys D. Cerebral venous infarction following thrombosis of the draining vein of a venous angioma (developmental abnormality). Cerebrovasc Dis 2000;10:235–238. Vieira Santos A, Saraiva P. Spontaneous isolated nonhaemorrhagic thrombosis in a child with development venous anomaly: case report and review of the literature. Childs Nerv Syst 2006;22:1631–1633. Hammoud D, Beauchamp N, Wityk R, Yousem D. Ischemic complication of a cerebral developmental venous anomaly: case report and review of the literature. J Comput Assist Tomogr 2002;26:633–636.

Neurology 72

January 6, 2009

93

DNM2 CNM mutation in the CMT region. Among the DNM2-related CNM, the phenotype appears intermediate, with an onset at the end of the first decade and a more rapid progression relative to the mild lateonset DNM2-CNM. Case report. The patient is a 34-year-old woman from a nonconsanguineous family from central Africa without history of neuromuscular disorders. She had a normal mental and motor postnatal development with independent ambulation acquired at 13 months. Symptoms started at the age of 7 years with

Figure

difficulty walking and running. At 10 years, she had facial weakness, bilateral ptosis, and a marked weakness in paraspinal, upper, and lower limb muscles. Motor nerve conduction velocities of the left common peroneal (49.4 m/second) and ulnar nerves (53.5 m/second) and latencies were normal for age. Electromyography (EMG) revealed a myopathic pattern without neuropathic signs. From the ages of 10 to 30 years, axial and limb muscle strength deteriorated continuously, but with a more pronounced aggravation between 11 and 15 years. She developed a severe ophthalmoparesis and progressive

Summary of mutated DNM2 amino acids in human diseases and muscle features from the patient

(A) DNM2 is composed of a GTPase domain (GTPase), a middle domain (Middle), a Pleckstrin homology (PH) domain, a GTPase effector domain (GED), and a proline-rich domain (PRD). CNM mutations (amino acids indicated in bold) are located in the middle domain and in the C-terminal part of the PH domain. CMT mutations are located in the N-terminal part of the PH domain. The novel DNM2-CNM (boxed) mutation p.E560K was identified in the protein region involved in CMT. The amino acids were numbered according to the isoform 1 (accession number: NP_001005360) which includes the four amino acids GEIL at positions 516 –519. (B–F) Computer tomography scans of upper and lower limb muscles of the patient at 28 years of age. Axial scanning sections corresponding to (B) ⫽ arm, middle plane; (C) ⫽ forearm; (D) ⫽ pelvic girdle muscles; (E) ⫽ tight, middle plane; and (F) ⫽ legs, middle plane. In (B), muscles of the arm are relatively less affected than the other muscular groups. Posterior compartments of the forearms (C) and thighs (E) are relatively more affected than anterior compartments at same level. Signal in proximal lower limb muscles is hypointense (D). At the level of the legs (F), both anterior and posterior compartments are affected. (G–I) Deltoid muscle biopsy performed at the age of 10 years that shows characteristic CNM histopathologic findings. Representative fields show central nuclei in 37% of fibers (G: hematoxylineosin staining), radial distribution of sarcoplasmic strands in 22% of fibers (H: nicotinamide adenine dinucleotidetetrazolium reductase staining), and predominance and hypotrophy of type 1 fibers (I: ATPase preincubated at pH 9.4 staining). Type 1 fibers represent 98% of fibers. 94

Neurology 72

January 6, 2009

difficulty climbing stairs, frequent falls, and dysphagia. At age 30 years, her maximum distance for walking was 20 meters and muscle CT scan assessment showed a diffuse involvement of limb muscles (figure, B through F). The posterior compartment of the forearms and thighs were relatively more affected than anterior compartments. In the legs, both anterior and posterior compartments were severely affected but the posterior compartment showed more marked abnormalities. At the last examination (34 years), she had severe arm weakness (shoulder antepulsion limited to 50° and abduction to 40°), had recurrent back pain, and required a wheelchair. Deep tendon reflexes were abolished in the four limbs and EMG showed a myopathic pattern without neuropathic signs. The vital capacity was 51% of the expected value at 12 years, 58% at 23 years, 67% at 30 years, and 45% at 34 years, consistent with a restrictive respiratory syndrome. Electrocardiogram and echocardiogram were normal. Serum creatine kinase levels and leukocyte count were in the normal range. Deltoid muscle biopsy at the age of 10 years revealed nuclear centralization, predominance and hypotrophy of type 1 fibers, and radial arrangement of sarcoplasmic strands (figure, G–I). Moderate endomysial fibrosis was observed, without evidence of necrosis or regeneration. A DNA sample was extracted from blood and the DNM2 gene was sequenced. We identified a heterozygous mutation in exon 15. The mutation (c.G1678A) induces the change of the highly conserved glutamate 560 to lysine (p.E560K) located in the PH domain (figure, A). Discussion. We report a novel DNM2 mutation associated with CNM with a topography of muscle involvement similar to the already reported DNM2-CNM patients,7 but with an unusual progressive course. From the ages of 10 to 15 years, she developed severe, generalized muscle weakness and required a wheelchair from age 30 years. Among the DNM2-CNM patients reported until now, the association of a stable restrictive respiratory syndrome with a relatively rapid evolution, compared to the mild late-onset CNM in which loss of ambulation mostly occurs after the 5th decade, is unique. Consequently, our results enlarge the clinical spectrum of the DNM2-CNM, which includes the severe neonatal and the slow progressive adult mild forms, and also intermediate CNM between these two phenotypes. The p.E560K mutation is positioned in the region of the PH domain in which all the CMT mutations were identified.4-6 In particular, the p.K559del

mutation was showed to cause axonal CMT in a patient with nerve conduction anomalies typical of axonal CMT and without evidence of muscular involvement on EMG and muscle biopsy.6 Inversely, in the patient reported here, nerve conduction studies were normal at age 10 years, EMG revealed only a myopathic pattern at 10 and 34 years, and muscle biopsy displayed the characteristic features of CNM. Therefore, the N-terminal part of the PH domain is not specifically linked to CMT but the cause of the tissue-specific phenotype remains to be determined. From INSERM (M.B., J.A.B., B.P., P.G., N.B.R.), U582, Institut de Myologie, Paris; UPMC Univ Paris 06 (B.P., M.B., P.G., N.B.R.), UMR_S582; Departamento de Neurologı´a y Neurocirugı´a (J.A.B.), HCUCH and Instituto de Ciencias Biome´dicas Universidad de Chile, Santiago; and Centre de Re´fe´rence de Pathologie Neuromusculaire Paris-Est (B.E.), AP-HP (M.F., P.G., N.B.R.), and Association Institut de Myologie (AIM) (M.F.), Groupe Hospitalier Pitie´-Salpeˆtrie`re, Paris, France. Supported by Institut National de la Sante´ et de la Recherche Me´dicale (INSERM), the Association Franc¸aise contre les Myopathies (AFM), and the Programme of Collaboration ECOSSECyT (N° A02S02). Jorge A. Bevilacqua was supported by the Programme Alban, the European Union Programme of High Level Scholarships for Latin America, scholarship No. E04E028343CL. Disclosure: The authors report no disclosures. Received April 24, 2008. Accepted in final form July 8, 2008. Address correspondence and reprint requests to Dr. Marc Bitoun, INSERM U582, Institut de Myologie, Groupe Hospitalier Pitie´Salpeˆtrie`re, 75013, Paris, France; [email protected] Copyright © 2009 by AAN Enterprises, Inc. ACKNOWLEDGMENT The authors thank Dr. N. Clarke for advice.

REFERENCES 1.

2.

3.

4.

5.

6.

7.

Jeannet PY, Bassez G, Eymard B, et al. Clinical and histologic findings in autosomal centronuclear myopathy. Neurology 2004;62:1484–1490. Bitoun M, Maugenre S, Jeannet P, et al. Mutations in dynamin 2 cause dominant centronuclear myopathy. Nat Genet 2005;37:1207–1209. Bitoun MP, Bevilacqua JA, Prudhon B, et al. Dynamin 2 mutations cause sporadic centronuclear myopathy with neonatal onset. Ann Neurol 2007;62:666–670. Zu¨chner S, Noureddine M, Kennerson M, et al. Mutations in the pleckstrin homology domain of dynamin 2 cause dominant intermediate Charcot-Marie-Tooth disease. Nat Genet 2005;37:289–294. Fabrizi GM, Ferrarini M, Cavallaro T, et al. Two novel mutations in dynamin-2 cause axonal Charcot-MarieTooth disease. Neurology 2007;69:291–295. Bitoun M, Stojkovic T, Prudhon B, et al. A novel mutation in the dynamin 2 gene in a Charcot-Marie-Tooth type 2 patient: clinical and pathological findings. Neuromuscul Disord 2008;18:334–338. Fischer D, Herasse M, Bitoun M, et al. Characterization of the muscle involvement in dynamin 2 related centronuclear myopathy. Brain 2006;129:1463–1469.

Neurology 72

January 6, 2009

95

M. Wendt, MD J. Wohlrab, MD S. Zierz, MD M. Deschauer, MD

96

EFALIZUMAB-INDUCED ISOLATED CEREBRAL LUPUS-LIKE SYNDROME

Drug-induced lupus erythematosus has been recognized as a side effect of more than 80 drugs since its first description in association with sulfadiazine in 1945.1 Novel bioengineered agents for treatment of autoimmune disorders can also induce lupus-like syndromes. This is especially described for tumor necrosis factor alpha (TNF␣) antagonists.2,3 Efalizumab is an immunosuppressive recombinant humanized IgG1 kappa isotype monoclonal antibody that binds to human CD11a. It is indicated for the treatment of adult patients with chronic moderate to severe plaque type psoriasis.4 Although efalizumab was been used for treatment of refractory subacute cutaneous lupus erythematosus,5 this drug can also induce the cutaneous form of this disease.6 However, a cerebral lupus-like syndrome has not been reported in association with efalizumab. We report a 56-year-old man who was admitted to the hospital because of psychosyndrome and movement disorder. His wife reported a change of his character 2 weeks before. A few days previously he developed uncontrolled movements of all limbs, so that he could not walk alone. There was a history of a severe recalcitrant plaque type psoriasis, which was futilely treated with cyclosporine A, methotrexate, and fumaric acid esters. For 3 months the patient received efalizumab (60 mg subcutaneous once a week). Clinical examination showed an awake patient who was incompletely orientated to time, place, person, and situation. Memory was severely disturbed. There were psychomotor retardation and confabulations. Generalized myoclonia by activation made the patient unable to stand without help. Cranial nerves, sensory examination, and tendon reflexes were normal. Babinski sign was negative. There was a normochromatic and normocytic anemia with hemoglobin of 4.9 mmol/L (normal 8.7– 11.2), erythrocytes of 2.64 Tpt/L (normal 4.60 – 6.20), and a hematocrit of 0.23% (normal 0.42– 0.52). The combination of increased consumption of iron (transferrin 1.5 g/L, normal 2.0–3.6 and ferritin 713.0 ng/mL, normal 28.0 –365.0) caused by inflammation together with low vitamin B12 levels (128 pmol/L, normal 133– 675) might explain the observed normochromatic and normocytic anemia. Coombs test was negative, arguing against autoimmune hemolytic anemia. Blood sedimentation rate (BSR) was 60/ 105, leukocytes were 3.66 Gpt/L (normal 3.80 – 9.80), and C-reactive protein was 16.2 mg/L (normal ⬍5). Complement factor C3 was 0.63 g/L (normal 0.90 –1.80) and C4 was normal. ANA titer was higher than 1:640, with a homogenous pattern. AntidsDNA antibodies were 383.70 U/mL (normal Neurology 72

January 6, 2009

⬍30.00) and anti-histone antibodies 12.80 U/mL (normal ⬍1.00). Antineuronal antibodies (anti-Yo, anti-Hu, anti-Ri), anti-thyroid antibodies, ANCA, ammonia, serum creatinine, electrolytes, and liver enzymes were normal. Urine analysis showed no proteinuria. CSF revealed a slight impairment of blood– brain barrier and elevated protein of 1,300 mg/L (normal 200 – 400). There was no intrathecal synthesis of immunoglobulin and oligoclonal bands were negative. Cell count, glucose, lactate, protein 14-3-3, tauprotein, ␤-amyloid, and NSE were unremarkable. MRI of the brain at admission and 2 weeks later was normal. EEG revealed generalized theta-waves but no epileptic discharges or triphasic waves. The patient showed no clinical abnormalities of cardiac or pulmonary function. ECG and chest X-ray were normal. Gastroscopy, coloscopy, abdominal sonography, and skin biopsy were unremarkable. Suspecting an autoimmunologic disease as a side effect of efalizumab, this therapy was terminated and prednisolone (100 mg daily) was administered. During the following days, the clinical condition improved. He became oriented to all qualities. The movement disorder was no longer detectable and he walked unaided. By reduction of prednisolone to 40 mg daily, within 1 month the clinical findings remained stable. The patient only complained about a slightly disturbed memory. At that time ANA titer was 1:320, dsDNA 213.40 U/mL, hemoglobin 7.1 mmol/L, and BSR 20/43. EEG showed alpha-rhythm without any focal signs. After 14 months, the patient showed no clinical abnormalities and was able to work. Prednisolone was reduced to 10 mg and mycophenolate (2,000 mg) was introduced. Acute psychosyndrome and movement disorder that is reversible upon therapy with prednisolone can be a manifestation of different autoimmune disorders. The patient had the typical laboratory constellation of lupus erythematosus with dsDNA antibodies and elevated BSR. There was no evidence for other subacute diseases presenting with movement disorder and psychiatric symptoms, such as Hashimoto encephalopathy, CreutzfeldtJakob disease, or other metabolic, inflammatory, or paraneoplastic diseases. The clinical symptoms together with antibody findings can be interpreted as an isolated cerebral lupus-like syndrome without multisystemic involvement. Although it cannot entirely be excluded that the disease occurred spontaneously, the close temporal association with efalizumab treatment suggests a drug-induced lupus-like syndrome. The anti-histone antibodies also support the view that this case was drug-induced.1 Efalizumab-induced cutaneous lupus erythematosus has already been described.6 This re-

port shows that efalizumab might also induce an isolated cerebral lupus-like syndrome. From the Departments of Neurology (M.W., S.Z., M.D.) and Dermatology (J.W.), Martin Luther University of Halle-Wittenberg, Germany. Disclosure: The authors report no disclosures. Received April 25, 2008. Accepted in final form August 5, 2008. Address correspondence and reprint requests to Dr. Matthias Wendt, Department of Neurology, Martin Luther University of HalleWittenberg, Ernst-Grube-Str. 40, 06097 Halle (Saale), Germany; [email protected] Copyright © 2009 by AAN Enterprises, Inc. 1.

2. 3.

4.

5.

6.

Vasoo S. Drug-induced lupus: an update. Lupus 2006;15: 757–761.

Callen JP. Complications and adverse reactions in the use of newer biologic agents. Semin Cutan Med Surg 2007;26:6–14. De Bandt M, Sibilia J, Le Loet X, et al. Systemic lupus erythematosus induced by anti-tumour necrosis factor alpha therapy: a French national survey. Arthritis Res Ther 2005;7:R545–R551. Kerns MJ, Graves JE, Smith DI, Heffernan MP. Off-label uses of biologic agents in dermatology: a 2006 update. Semin Cutan Med Surg 2006;25:226–240. Clayton TH, Ogden S, Goodield M. Treatment of refractory subacute cutaneous lupus erythematosus with efalizumab. J Am Acad Dematol 2006;54:892–895. Bentley DD, Graves JE, Smith DI, Hefernan MP. Efalizumab-induced subacute cutaneous lupus erythematosus. J Am Acad Dematol 2006;54:S242–243.

www.neurology.org Offers Important Information to Patients and Their Families The Neurology® Patient Page provides: • A critical review of ground-breaking discoveries in neurologic research that are written especially for patients and their families • Up-to-date patient information about many neurologic diseases • Links to additional information resources for neurologic patients All Neurology Patient Page articles can be easily downloaded and printed, and may be reproduced to distribute for educational purposes. Click on the Patient Page icon on the home page (www. neurology.org) for a complete index of Patient Pages.

Activate Your Online Subscription At www.neurology.org, subscribers can now access the full text of the current issue of Neurology® and back issues. Select the “Login instructions” link that is provided on the Help screen. Here you will be guided through a step-by-step activation process. Neurology® online offers: • e-Pub ahead of print • Extensive search capabilities • Complete online Information for Authors • Access to Journal content in both Adobe Acrobat PDF and HTML formats • Links to PubMed • Examinations on designated articles for CME credit • Resident & Fellow section • Patient Page • Access to in-depth supplementary scientific data

Neurology 72

January 6, 2009

97

NEUROIMAGES

T-cell neurolymphomatosis involving cauda equina and sciatic nerves

Figure

CT-PET fusion images showing increased fluorodeoxyglucose (FDG) uptake in the sciatic nerves and cauda equina (arrows)

Left: Transaxial and coronal images demonstrate increased uptake in the distal sciatic nerves (arrows). Right: Sagittal image demonstrating increased uptake in the cauda equina (arrow) and multiple other areas (asterisks).

A 60-year-old man with T-cell lymphoma post chemotherapy presented with progressive left greater than right lower extremity weakness and allodynia. Fluorodeoxyglucose-PET was consistent with neoplastic infiltration of multiple lumbosacral roots and sciatic nerves (figure). Spinal fluid cytology showed malignant T-cells, supporting the diagnosis of neurolymphomatosis. Resolution of the imaging abnormalities and clinical improvement occurred following high dose intrathecal methotrexate. Neurolymphomatosis is an especially rare complication of T-cell malignancies.1 If spinal fluid cytology cannot make the diagnosis, as in this case, radiographic directed proximal nerve and root biopsy may be helpful.2 Steven C. Kosa, MD, Patrick J. Peller, MD, Christopher J. Klein, MD, Rochester, MN Disclosure: The authors report no disclosures. Address correspondence and reprint requests to Dr. Christopher Klein, Mayo Clinic Department of Neurology, 200 1st Street SW, Rochester, MN 55905; [email protected] 1. 2.

98

Kuroda Y, Nakata H, Kakigi R, Oda K, Shibasaki H, Nakashiro H. Human neurolymphomatosis by adult T-cell leukemia [see comment]. Neurology 1989;39:144–146. Dyck PJB, Spinner RJ, Amrami KK, Klein CJ, Engelstad JK, Dyck PJ. Targeted fascicular biopsy of proximal nerves with MRI abnormality may be diagnostically informative. J Periph Nerv Syst 2007;(suppl 1):27–28.

Copyright © 2009 by AAN Enterprises, Inc.

RESIDENT & FELLOW SECTION Section Editor Mitchell S.V. Elkind, MD, MS

Larry E. Davis, MD, FAAN Molly K. King, MD Betty J. Skipper, PhD

Education Research: Assessment of neurology resident clinical competencies in the neurology clinic ABSTRACT

Background: Objective evaluation of neurology resident clinical skills is required by the American Board of Psychiatry and Neurology and is important to insure improvement in clinical competency throughout their residency.

Methods: In this study, neurology residents from all 3 years of training and neurology faculty Address correspondence and reprint requests to Dr. Larry E. Davis, Neurology Service, New Mexico VA Health Care System, 1501 San Pedro Drive S.E., Albuquerque, NM 87108 [email protected]

independently completed a form on new clinic patients documenting their decisions on anatomic localization, diagnosis, diagnostic tests, and management.

Results: Compared to the attending patient evaluation, we found significant improvement in identical scoring by year of residency training. All resident years outperformed medical students in the neurology clerkship. Conclusion: Our clinical assessment form adds one more tool to the list of currently used assessment methods to evaluate resident clinical competency. Neurology® 2009;72:e1–e3

Neurology residency trains a physician to become a competent neurologist. For a neurology resident to qualify to take the American Board of Psychiatry and Neurology examination, the residency program director must certify that he or she has successfully completed the required training and verify successful mastery of in-residency clinical skills.1 Objective examinations including the National neurology in-service examination as well as departmental internal examinations assess attainment of an adequate neurologic knowledge base. The greater challenge is knowing that the trainees can apply that knowledge base to patients in clinical settings. We report a method that successfully evaluated neurology residents’ clinical competency on different parts of the patient encounter on multiple occasions in a general neurology clinic. METHODS We evaluated all neurology residents in this prospective study from July 2000 through December 2002 at the New Mexico VA Health Care System. Over the 2.5 years, 11 residents in postgraduate year (PGY) 2, 11 residents in PGY3, and 10 residents in PGY4 attended VA general neurology clinics and participated in this study approved by the VA research committee and University of New Mexico Human Research Review Committee. Similar to our published study on neurology clerkship medical students,2,3 residents completed forms on their new patients (see the form on the Neurology® Web site at www.neurology.org). Residents had available the written consultation request and the electronic medical record. Having conducted a history and examination, the residents then completed the form before they presented the patient to one of five board certified academic neurology attendings. The form requested information about the 1) anatomic location of the suspected lesion, 2) key diagnosis, 3) residents’ level of diagnostic certainty regarding the diagnosis, 4) diagnostic tests they would order, and 5) management they recommended. After the resident’s oral patient presentation, the attending and resident returned to the patient where the attending independently conducted a focused history and examination and separately completed on the resident’s form the same questions. Forms were collected and scored by the authors. The attending neurologist response was considered the definitive answer. Differences in anatomic localization were defined as close (two sites were anatomically adjacent in the nervous system) or anatomically distant from each other. Specific diagnosis was scored as identical or different. Then differing diagnoses were scored as close (i.e., both diagnoses in the same broad category as in diabetic vs alcoholic peripheral neuropathy) or distant (i.e., brain tumor and tension headache). We scored proposed diagnostic tests as identical or different. When different, the form was subscored as different on neuroimaging tests, physiologic tests, blood tests, and diagnostic consultations since residents could differ from faculty in more than one test category. We also recorded whether the resident ordered fewer, more, or a similar number of tests than the attending. Proposed treatments were scored as identical, close (such as different commonly used medication for the same condition), or distant Supplemental data at www.neurology.org From the Neurology Service (L.E.D., M.K.K.), New Mexico VA Health Care System; and the Departments of Neurology (L.E.D., M.K.K.) and Family and Community Medicine (B.J.S.), University of New Mexico School of Medicine, Albuquerque. Disclosure: The authors report no disclosures. Copyright © 2009 by AAN Enterprises, Inc.

e1

Table

Agreement between resident by year of training and attending on different parts of examination

PGY2, n (%)

PGY3, n (%)

PGY4, n (%)

All residents, n (%)

124 (69)

76 (72)

101 (84)

301 (74)

Close anatomically

32 (18)

17 (16)

14 (12)

Distant anatomically

19 (10)

8 (8)

4 (3)

31 (8)

6 (3)

4 (4)

1 (1)

11 (3)

Scoring category Anatomic location agreement Identical location

Resident did not know and left blank Faculty left blank so cannot score

1

2

2

63 (16)

5

Diagnosis agreement Identical diagnosis

129 (71)

78 (73)

93 (76)

Same ballpark diagnosis

24 (13)

12 (11)

16 (13)

52 (13)

Very different diagnosis

25 (14)

15 (14)

4 (3)

44 (11)

4 (2)

2 (2)

9 (7)

15 (4)

Resident did not know and left blank Faculty left blank so cannot score

0

0

0

300 (73)

0

Diagnostic test agreement Identical tests requested

110 (61)

59 (55)

94 (77)

263 (64)

Different

52 (29)

40 (37)

19 (16)

111 (27)

Resident did not know and left blank

19 (10)

8 (7)

9 (7)

36 (9)

Faculty left blank so cannot score

1

0

0

1

Number of diagnostic tests Same number of tests ordered

113 (70)

66 (67)

96 (84)

275 (74)

4 (2)

7 (7)

4 (4)

15 (4)

44 (27)

26 (26)

Faculty ordered more tests Resident ordered more tests Blank so cannot score

21

8

14 (12) 8

84 (22) 37

Diagnostic tests differing between resident and attending Blood test disagreement

22 (42)

11 (28)

5 (26)

38 (35)

Neuroimaging disagreement

20 (38)

16 (40)

8 (42)

44 (40)

Neurophysiologic test disagreement

18 (35)

22 (55)

9 (47)

49 (44)

2 (5)

3 (16)

11 (10)

236 (59)

Consult request disagreement

6 (12)

Treatment agreement Identical

96 (54)

61 (58)

79 (66)

Close

53 (30)

25 (24)

19 (16)

8 (4)

2 (2)

1 (1)

Resident did not know and left blank

21 (12)

17 (16)

21 (18)

Faculty left blank so cannot score

4

2

Distant

2

97 (24) 11 (3) 59 (15) 8

PGY ⫽ postgraduate year; n ⫽ number of evaluations.

(such as triptan vs anticonvulsant for a seizure patient). We scored categories blank when the resident placed a question mark in the area, entered only information not pertaining to the question, or left the space entirely blank. Data were entered onto a Microsoft Access database with a code for each resident and year of residency but without patient identifiers. Similarities and differences between the two responses were statistically analyzed using ␹2 and Mantel-Haenszel tests. e2

Neurology 72

January 6, 2009

RESULTS We evaluated 411 new patient encounters from 17 residents. Over the 30 consecutive months of the study, 182 encounters were from 11 residents in PGY2, 107 encounters were from 11 residents in PGY3, and 122 encounters were from 10 residents in PGY4. Three forms could not be scored because attendings failed to complete any part of their form and eight additional forms had specific parts of the faculty form incomplete.

The table shows the results by parts of the examination and by resident PGY. The percent of all resident years combined demonstrating identical agreement with attending differed by parts of the patient encounter (␹2 [3 df ] ⫽ 30.58; p ⬍ 0.001). For all residents, identical agreement was 74% for anatomic lesion location, 73% for specific diagnosis, 64% for diagnostic tests recommended, and 59% for proposed treatment. There were differences by year of resident training. Residents improved their scoring relative to faculty by year of training (table) as seen in the MantelHaenszel tests for trends across the 3 years of residency training for anatomic location agreement, diagnosis agreement, diagnostic test agreement, and treatment agreement (p ⬍ 0.001). There was an association between resident level of certainty of diagnosis and agreement with faculty specific diagnosis (␹2 [6 df ] ⫽ 30.42; p ⬍ 0.001). Among cases where resident diagnostic certainty was high, the all resident years–faculty agreement was identical for 86% compared to only 36% identical agreement for cases where residents reported low certainty. Residents ordered the same number of tests as the attendings in 74% of the visits but ordered more tests than attendings in 22%. The table shows how residents and attendings differed by type of test ordered. Residents and attendings differed more on types of neurophysiologic tests and neuroimaging tests ordered than in the ordering of blood tests or consultation requests. Residents agreed with attendings on identical treatment plans 54% of the time in PGY2, 58% in PGY3, and 66% in PGY4. When the two differed in treatment plans, residents tended to neglect to propose management that included patient education, simple lifestyle modifications, referral to family support groups, and recommendations for equipment to prevent secondary complications. Compared to our study on medical student attending the same general neurology clinics over the same time period,2 residents in all years of their training were in closer agreement to attendings than were the medical students for all broad categories (p ⬍ 0.001).

Although not unexpected, we were pleased to learn that residents in each training year outperformed those in previous years of training. Due to the limited 30-month duration of the study, we could not determine for an individual resident how he or she progressed over the 3 years. However, residents could easily be tracked using this form over the 3 years of residency to insure they were progressing in clinical competence. Once a residency program acquired sufficient experience with their residents using this form, specific standards for passing each year and certification of clinical competence could be developed. We also use this form to identify specific areas of clinical disease or neurophysiology where a resident is weak. When recognized, the resident is assigned a “learning issue” related to the deficiency. Limitations of this study include that residents were able to review the consult request and electronic medical record before seeing the patient. In some circumstances, the diagnosis may have been previously made by others but the resident would still have to decide if the other diagnosis was correct. However, this is the world they will function in when they become a practicing neurologist. It is possible that some residents working with an attending over 1–2 years may have recognized the types of tests usually ordered by a given attending or their particular treatment style. When questioned about this possibility, however, residents felt this was unlikely. To become a quality neurologist, the trainee must master large bodies of clinical and basic neuroscience knowledge. The final test of trainees’ efforts is not what they know but what they do.4 It is recognized that assessment drives learning. Careful objective as-

DISCUSSION

sessment has the potential to inspire learning, influence values, and reinforce competence.5 The challenge for a training program is to use objective assessment methods to evaluate clinical performance and determine both how the resident progresses from year to year and whether he or she achieves a level of clinical performance satisfactory to the training program and American Board of Psychiatry and Neurology. The clinical assessment form presented here adds one more tool to the list of currently used assessment methods utilized by many medical schools.6 AUTHOR CONTRIBUTIONS Statistical analysis was performed by B.J.S.

ACKNOWLEDGMENT The authors thank the University of New Mexico residents; Drs. John Adair, Kurt Fiedler, and Glenn Graham; and Keena Neal for data entry.

REFERENCES 1. American Board of Psychiatry and Neurology. Information for applicants for certification in neurology and neurology with special qualification in child neurology. Available at: www.abpn.com/Initial_Neuro.htm. Accessed January 20, 2008. 2. Davis LE, King MK. Assessment of medical student clinical competencies in the neurology clinic. Neurology 2007; 68:597–599. 3. Davis LE, King MK. Evaluating medical students’ performance in a clinical setting. Nature Clin Pract Neurol 2007;3:702–703. 4. Cooke M, Irby DM, Sullivan W, Ludmerer KM. American medical education 100 years after the Flexner Report. N Engl J Med 2006;355:1339–1344. 5. Epstein RM, Hundert EM. Defining and assessing professional competence. JAMA 2002;287:226–235. 6. Epstein RM. Assessment in medical education. N Engl J Med 2007;356:387–396.

Neurology 72

January 6, 2009

e3

RESIDENT & FELLOW SECTION Section Editor Mitchell S.V. Elkind, MD, MS

Ashok Kumar, MD, DM Amar Kumar Singh

Teaching NeuroImage: Inverted V sign in subacute combined degeneration of spinal cord Figure 1

Sagittal T2-weighted MR image of the cervical spinal cord shows hyperintensity in the dorsal aspect of the cord (C1 to C4)

Address correspondence and reprint requests to Dr. Ashok Kumar, Neurology Department, Indira Gandhi Institute of Medical Sciences, D4/3, I.G.I.M.S. Campus, Raja-Bazar, Sheikhpura, Patna, Bihar, India [email protected]

Figure 2

Transverse T2-weighted MR image of the cervical spinal cord at C2 level demonstrates bilateral symmetric signal intensity within the dorsal columns (inverted V sign)

weighted MRI of the cervical spine showed hyperintensity of the cord extending from the level of C1 to C4 (figure 1). Transverse T2-weighted MRI at the C2 level demonstrated bilateral symmetric signal intensity abnormality within the dorsal columns (inverted V sign; figure 2). Hematologic tests showed macrocytic, hypochromic anemia with pancytopenia and hypersegmented neutrophils. Mean corpuscular volume was 110 fL (normal 82–92 fL), and serum B12 concentration 108 pg/mL (normal 200 – 600 pg/mL). Subacute combined degeneration of the spinal cord due to vitamin B12 deficiency was diagnosed.1,2 A 60-year-old man presented with 3 months of finger paresthesias. Neurologic examination showed pseudoathetosis in arms, loss of joint position and vibration sensation in toes and fingers, brisk deep tendon reflexes in arms and knees with depressed ankle jerks, and extensor plantar responses. T2-

From Chaudhary Digital Imaging, Patna, India. Disclosure: The authors report no disclosures.

e4

Copyright © 2009 by AAN Enterprises, Inc.

REFERENCES 1. Michelle JN, Sam U Ho. Subacute combined degeneration. Radiology 2005;237:101–105. 2. Timms SR, Cure JK, Kurent JE. Subacute combined degeneration of spinal cord. Am J Neuroradiol 1993;14: 1224–1227.

Correspondence

CLINICAL SPECTRUM OF VOLTAGE-GATED POTASSIUM CHANNEL AUTOIMMUNITY

To the Editor: We were interested to see the report on the spectrum of voltage-gated potassium channel autoimmunity but feel that the results could be misleading. Tan et al.1 only tested sera for VGKC antibodies by direct radioimmunoprecipitation (RIA) if they had previously been found positive for binding to the molecular layer of the cerebellum on routine screening for paraneoplastic antibodies. Therefore, their sample does not include sera sent specifically for VGKC antibodies and is likely biased towards paraneoplastic cases as they state. This may explain why their numbers are surprisingly low: only 80 cases in 6 years. Over the last year, we received 3000 sera specifically for VGKC antibody testing by RIA, finding 250 positive sera (⬎0.1 nmol/L) of which 70 had values ⬎0.4 nmol/L. There were some clinical manifestations that were unexpected, which were extrapyramidal and cranial nerve/brainstem disorders. Other syndromes that have been reported in patients with VGKC antibodies include cortical and subcortical features, hypothalamic and sleep disturbance, myoclonus, and autonomic and peripheral nerve hyperexcitability. In particular, Morvan syndrome may be under-reported but can include the CNS and autonomic and peripheral disorders.2 Moreover, the bias towards paraneoplastic cases, confirmed by the finding that 47% had or were considered at high risk of developing tumors, indicates that some of the manifestations reported may represent features of a paraneoplastic panencephalitis rather than a syndrome specifically related to the VGKC antibodies. In addition, the levels of VGKC antibodies associated with any particular clinical manifestation, however broadly defined, were not stated. For example, it is unclear whether the patients with extrapyramidal disorders had relatively low titers and associated tumors. Low VGKC titers have previously been reported in paraneoplastic limbic encephalitis and may represent part of the immune response to the tumor.3 In our experience, high titers (above 0.4 nmol/L) are almost always associated with non-paraneoplastic limbic or epilepsy-

related syndromes4,5 although some (⬍10%) may have a thymoma. We agree that VGKC antibody testing can be helpful in routine testing and that the full clinical spectrum needs to be described. However, this should be based on patients screened primarily with the RIA unless a better method is established. In addition, it should be described separately for paraneoplastic and non-paraneoplastic cases and include details of the titers of VGKC antibodies associated with the different clinical phenotypes. Angela Vincent, Camila Buckley, Bethan Lang, Sarosh Irani, Oxford, UK Disclosure: The authors report that their department receives revenue for performing VGKC antibody assays (and others).

Reply from the Authors: We thank Vincent et al. for their comments. Per their suggestion, we applied the high-titer threshold of 0.4 nmol/L to analyze our RIA for VGKC autoantibodies and found that 51 of 72 patients (71%) in our report had high titers. Median age at onset of neurologic disorder was 64 years, 53% were female, and 56% were smokers.1 Of these patients, 31% had confirmed neoplasia and 14% had suspected neoplasia, 10% had neither seizures nor encephalopathy, and 41% had extracerebral manifestations. Extrapyramidal (20%) and brainstem/cranial nerve disorders (12%) remained prevalent in this high-titer cohort. To conclude, our experience does not support the correspondent’s suggestion that “high-titers” of VGKC autoantibodies “are almost always associated with non-paraneoplastic limbic or epilepsy-related syndromes.” As we stated, the method of ascertaining patients is crucial to defining the clinical spectrum of VGKC autoimmunity. Previous literature has focused on the association of VGKC autoantibodies with neurologically defined presentations including Isaacs syndrome, Morvan syndrome, and non-paraneoplastic limbic encephalitis.2–5 The problem with defining the neurologic and oncologic associations of an autoantibody on the basis of physician-requested testing is that it precludes recognition of a broader immunobiological spectrum of disease, as we have previously demonstrated for other markers of neurologic autoimmunity.6 –9 Neurology 72

January 6, 2009

99

Our serologic evaluation for neurologic autoimmunity is not restricted to an arbitrary panel of antigens.9 It is an algorithmic cascade which includes reflexive testing prompted by findings on a standardized immunofluorescence assay (screening for IgG binding selectively to neural tissues) and RIAs for cation channel autoantibodies. It is our experience that patients for whom VGKC autoantibody testing is physician-requested on the basis of “syndromic” neurologic presentation are frequently seronegative. Supporting our recommendation for a comprehensive serologic evaluation when an autoimmune neurologic disorder is suspected, 46% of patients with Isaacs syndrome are VGKC antibody negative and 19% of those are ganglionic neuronal acetylcholine receptor antibody positive.10 Our study avoided the bias inherent in defining the clinical spectrum associated with VGKC autoantibodies because testing by RIA was performed algorithmically without knowledge of clinical presentation, prompted strictly by detection of a VGKCcompatible staining pattern in immunofluorescence screening. We do not suggest that immunofluorescence is the most sensitive method for detecting VGKC autoantibodies. Our data support our conclusion “that VGKC autoantibody testing [is justified] in evaluation of patients with idiopathic neurologic disorders of subacute onset.”1 Sean J. Pittock, K. Meng Tan, Rochester, MN Disclosure: The authors report no disclosures. Copyright © 2009 by AAN Enterprises, Inc. 1.

2.

3.

4.

5.

6.

7.

8.

100

Tan KM, Lennon VA, Klein CJ, Boeve BF, Pittock SJ. Clinical spectrum of voltage-gated potassium channel autoimmunity. Neurology 2008;70:1883–1890. Liguori R, Vincent A, Clover L, et al. Morvan’s syndrome: peripheral and central nervous system and cardiac involvement with antibodies to voltage-gated potassium channels. Brain 2001;124:2417–2426. Pozo-Rosich P, Clover L, Saiz A, Vincent A, Graus F. Voltage-gated potassium channel antibodies in limbic encephalitis. Ann Neurol 2003;54:530 –533. Vincent A, Buckley C, Schott JM, et al. Potassium channel antibody-associated encephalopathy: a potentially immunotherapy-responsive form of limbic encephalitis. Brain 2004;127:701–712. Thieben MJ, Lennon VA, Boeve BF, Aksamit AJ, Keegan M, Vernino S. Potentially reversible autoimmune limbic encephalitis with neuronal potassium channel antibody. Neurology 2004;62:1177–1182. Pittock SJ, Lucchinetti CF, Parisi JE, et al. Amphiphysin autoimmunity: paraneoplastic accompaniments. Ann Neurol 2005;58:96 –107. Pittock SJ, Yoshikawa H, Ahlskog JE, et al. Glutamic acid decarboxylase autoimmunity with brainstem, extrapyramidal, and spinal cord dysfunction. Mayo Clin Proc 2006; 81:1207–1214. Lucchinetti CF, Kimmel DW, Lennon VA. Paraneoplastic and oncologic profiles of patients seropositive for type 1

Neurology 72

January 6, 2009

9.

10.

antineuronal nuclear autoantibodies. Neurology 1998;50: 652– 657. Pittock SJ, Kryzer TJ, Lennon VA. Paraneoplastic antibodies coexist and predict cancer, not neurological syndrome. Ann Neurol 2004;56:715–719. Vernino S, Lennon VA. Ion channel and striational antibodies define a continuum of autoimmune neuromuscular hyperexcitability. Muscle Nerve 2002;26:702–707.

MULTIPLE SCLEROSIS AND CANNABIS: A COGNITIVE AND PSYCHIATRIC STUDY

To the Editor: Drs. Ghaffar and Feinstein1 report important new data associating regular smoking of street cannabis in patients with multiple sclerosis (MS) with more extensive cognitive abnormalities compared to patients with MS who do not use cannabis. In 2006 we reported subtle deficits in specific neuropsychological domains in heavy, long-term cannabis users that were in the unintoxicated state.2 The Ghaffar and Feinstein report provides evidence that patients with MS might suffer additional cognitive decline when smoking cannabis regularly.1 However, cognitive deficits that have been attributed to regular recreational use of cannabis are not necessarily extended to controlled pharmaceutical use of cannabis-based medicinal extracts (CBMEs). However, the findings of Ghaffar and Feinsten form the basis on which to raise concern regarding potential cognitive adverse effects of long-term regular cannabis use in MS. We recently reviewed MS clinical trial data of CBMEs and specifically focused on parallel assessments of cognitive status in order to establish whether any disruptive effects on cognition had been documented in these trials.3 Available data indicated that no significant cognitive decline occurs after relatively short-term administration of CBMEs. However, safer and more valid conclusions will have to await the results of long-term, large-scale, systematic clinical trials of CBMEs. In addition, the Ghaffar and Feinstein report did not adjust for premorbid cognitive ability between groups of patients with MS.1 By matching groups on measures of crystallized intelligence that are relatively resilient to brain impairment (i.e., Wechsler Abbreviated Scale of Intelligence [Vocabulary scale] or National Adult Reading Test), groups may be more equal with regard to premorbid cognitive abilities. MS cannabis users reporting greater cognitive deficits may reflect premorbid cognitive impairments rather than consequences of cannabis exposure. Another important limitation of this study1 concerns the potential neurocognitive effects of cannabis withdrawal syndrome. This may have influenced the results as MS cannabis users were noted to have used cannabis 1–30 days before testing.4

Because the study does not provide mean duration of abstinence from cannabis use by patients with MS, we might assume that the findings regarding the more extensive cognitive abnormalities actually reflect acute effects of cannabis on cognition and cannot be certain that these differences would persist after adequate abstinence periods. Despite the important contribution of this new study, the findings should be interpreted within the context of these important caveats. Lambros Messinis, Panagiotis Papathanasopoulos, Patras, Greece Disclosure: The authors report no disclosures.

Reply from the Authors: Drs. Messinis and Papathanasopoulos raise interesting and pertinent questions related to our findings that inhaled cannabis is associated with greater impairment in speed of information processing in patients with MS.1 We agree that this finding may not apply to CBMEs and acknowledged this in our article’s concluding sentence. However, it is still unclear whether the long-term use of pharmaceutically derived CBMEs affects cognitive function, a point made by Drs. Messinis and Papathanasopoulos in their recent comprehensive review.3 Other factors could have influenced cognitive functioning in our sample apart from the use of inhaled cannabis. We did not use the ANART or the vocabulary subscale of the Wechsler Abbreviated Scale of Intelligence to control for premorbid intelligence, but rather relied on the number of years of completed education, which did not differ between our cannabis users and control subjects. We subsequently ran a second analysis which reviewed the possible differences in occupational category (professional and skilled versus other) and again did not find between-group differences (␹2 ⫽ 0.2; p ⫽ 0.0.72; Fisher exact test). While these data are not as robust as those obtained from psychometric measures, they indicate that inhaled cannabis rather than premorbid intellect explains the cognitive findings.

The question of whether the greater cognitive deficits recorded in our cannabis users were influenced by a cannabis withdrawal syndrome is intriguing. In general, while the data supporting the validity of this syndrome appear compelling, it is less clear whether altered cognition is part of the clinical picture. Only one out of 10 studies investigating the clinical picture of cannabis abstinence listed impaired concentration as the sole cognitive complaint,4 leading Budney et al.5 to omit any reference to impaired cognition as part of their suggested criteria for the syndrome. Based on the existing literature, it seems unlikely that the cognitive problems identified in our cannabis smokers are a function of a withdrawal syndrome, but we cannot be certain of this given the limitations in our data. We did not collect information on precisely how much time had elapsed between our subjects smoking cannabis and their completing the neuropsychological battery. As with so much in the field, further research is needed to explore these issues. Anthony Feinstein, Omar Ghaffar, Toronto, Ontario, Canada Disclosure on article to which this Correspondence refers: O.G. has received honoraria from Cerebrio, a continuing medical education company. A.F. has received lecture honoraria from Berlex Canada, Serono Canada, Serono USA, Teva Neuroscience, and Avanir Pharmaceuticals. Copyright © 2009 by AAN Enterprises, Inc. 1.

2.

3.

4.

5.

Ghaffar O, Feinstein A. Multiple sclerosis and cannabis: a cognitive and psychiatric study. Neurology 2008;71: 164 –169. Messinis L, Kyprianidou A, Malefaki S, Papathanasopoulos P. Neuropsychological deficits in long-term frequent cannabis users. Neurology 2006;66:737–739. Papathanasopoulos P, Messinis L, Lyros E, Kastellakis A, Panagis G. Multiple sclerosis, cannabinoids and cognition. J Neuropsychiatry Clin Neurosci 2008;20: 36 –51. Budney AJ, Hughes JR, Moore BA, et al. Review of the validity and significance of cannabis withdrawal syndrome. Am J Psychiatry 2004;161:1967–1977. Budney AJ, Hughes JR. The cannabis withdrawal syndrome. Curr Opin Psychiatry 2006;19:233–238.

Neurology 72

January 6, 2009

101

Correspondence

CLINICAL SPECTRUM OF VOLTAGE-GATED POTASSIUM CHANNEL AUTOIMMUNITY

To the Editor: We were interested to see the report on the spectrum of voltage-gated potassium channel autoimmunity but feel that the results could be misleading. Tan et al.1 only tested sera for VGKC antibodies by direct radioimmunoprecipitation (RIA) if they had previously been found positive for binding to the molecular layer of the cerebellum on routine screening for paraneoplastic antibodies. Therefore, their sample does not include sera sent specifically for VGKC antibodies and is likely biased towards paraneoplastic cases as they state. This may explain why their numbers are surprisingly low: only 80 cases in 6 years. Over the last year, we received 3000 sera specifically for VGKC antibody testing by RIA, finding 250 positive sera (⬎0.1 nmol/L) of which 70 had values ⬎0.4 nmol/L. There were some clinical manifestations that were unexpected, which were extrapyramidal and cranial nerve/brainstem disorders. Other syndromes that have been reported in patients with VGKC antibodies include cortical and subcortical features, hypothalamic and sleep disturbance, myoclonus, and autonomic and peripheral nerve hyperexcitability. In particular, Morvan syndrome may be under-reported but can include the CNS and autonomic and peripheral disorders.2 Moreover, the bias towards paraneoplastic cases, confirmed by the finding that 47% had or were considered at high risk of developing tumors, indicates that some of the manifestations reported may represent features of a paraneoplastic panencephalitis rather than a syndrome specifically related to the VGKC antibodies. In addition, the levels of VGKC antibodies associated with any particular clinical manifestation, however broadly defined, were not stated. For example, it is unclear whether the patients with extrapyramidal disorders had relatively low titers and associated tumors. Low VGKC titers have previously been reported in paraneoplastic limbic encephalitis and may represent part of the immune response to the tumor.3 In our experience, high titers (above 0.4 nmol/L) are almost always associated with non-paraneoplastic limbic or epilepsy-

related syndromes4,5 although some (⬍10%) may have a thymoma. We agree that VGKC antibody testing can be helpful in routine testing and that the full clinical spectrum needs to be described. However, this should be based on patients screened primarily with the RIA unless a better method is established. In addition, it should be described separately for paraneoplastic and non-paraneoplastic cases and include details of the titers of VGKC antibodies associated with the different clinical phenotypes. Angela Vincent, Camila Buckley, Bethan Lang, Sarosh Irani, Oxford, UK Disclosure: The authors report that their department receives revenue for performing VGKC antibody assays (and others).

Reply from the Authors: We thank Vincent et al. for their comments. Per their suggestion, we applied the high-titer threshold of 0.4 nmol/L to analyze our RIA for VGKC autoantibodies and found that 51 of 72 patients (71%) in our report had high titers. Median age at onset of neurologic disorder was 64 years, 53% were female, and 56% were smokers.1 Of these patients, 31% had confirmed neoplasia and 14% had suspected neoplasia, 10% had neither seizures nor encephalopathy, and 41% had extracerebral manifestations. Extrapyramidal (20%) and brainstem/cranial nerve disorders (12%) remained prevalent in this high-titer cohort. To conclude, our experience does not support the correspondent’s suggestion that “high-titers” of VGKC autoantibodies “are almost always associated with non-paraneoplastic limbic or epilepsy-related syndromes.” As we stated, the method of ascertaining patients is crucial to defining the clinical spectrum of VGKC autoimmunity. Previous literature has focused on the association of VGKC autoantibodies with neurologically defined presentations including Isaacs syndrome, Morvan syndrome, and non-paraneoplastic limbic encephalitis.2–5 The problem with defining the neurologic and oncologic associations of an autoantibody on the basis of physician-requested testing is that it precludes recognition of a broader immunobiological spectrum of disease, as we have previously demonstrated for other markers of neurologic autoimmunity.6 –9 Neurology 72

January 6, 2009

99

Our serologic evaluation for neurologic autoimmunity is not restricted to an arbitrary panel of antigens.9 It is an algorithmic cascade which includes reflexive testing prompted by findings on a standardized immunofluorescence assay (screening for IgG binding selectively to neural tissues) and RIAs for cation channel autoantibodies. It is our experience that patients for whom VGKC autoantibody testing is physician-requested on the basis of “syndromic” neurologic presentation are frequently seronegative. Supporting our recommendation for a comprehensive serologic evaluation when an autoimmune neurologic disorder is suspected, 46% of patients with Isaacs syndrome are VGKC antibody negative and 19% of those are ganglionic neuronal acetylcholine receptor antibody positive.10 Our study avoided the bias inherent in defining the clinical spectrum associated with VGKC autoantibodies because testing by RIA was performed algorithmically without knowledge of clinical presentation, prompted strictly by detection of a VGKCcompatible staining pattern in immunofluorescence screening. We do not suggest that immunofluorescence is the most sensitive method for detecting VGKC autoantibodies. Our data support our conclusion “that VGKC autoantibody testing [is justified] in evaluation of patients with idiopathic neurologic disorders of subacute onset.”1 Sean J. Pittock, K. Meng Tan, Rochester, MN Disclosure: The authors report no disclosures. Copyright © 2009 by AAN Enterprises, Inc. 1.

2.

3.

4.

5.

6.

7.

8.

100

Tan KM, Lennon VA, Klein CJ, Boeve BF, Pittock SJ. Clinical spectrum of voltage-gated potassium channel autoimmunity. Neurology 2008;70:1883–1890. Liguori R, Vincent A, Clover L, et al. Morvan’s syndrome: peripheral and central nervous system and cardiac involvement with antibodies to voltage-gated potassium channels. Brain 2001;124:2417–2426. Pozo-Rosich P, Clover L, Saiz A, Vincent A, Graus F. Voltage-gated potassium channel antibodies in limbic encephalitis. Ann Neurol 2003;54:530 –533. Vincent A, Buckley C, Schott JM, et al. Potassium channel antibody-associated encephalopathy: a potentially immunotherapy-responsive form of limbic encephalitis. Brain 2004;127:701–712. Thieben MJ, Lennon VA, Boeve BF, Aksamit AJ, Keegan M, Vernino S. Potentially reversible autoimmune limbic encephalitis with neuronal potassium channel antibody. Neurology 2004;62:1177–1182. Pittock SJ, Lucchinetti CF, Parisi JE, et al. Amphiphysin autoimmunity: paraneoplastic accompaniments. Ann Neurol 2005;58:96 –107. Pittock SJ, Yoshikawa H, Ahlskog JE, et al. Glutamic acid decarboxylase autoimmunity with brainstem, extrapyramidal, and spinal cord dysfunction. Mayo Clin Proc 2006; 81:1207–1214. Lucchinetti CF, Kimmel DW, Lennon VA. Paraneoplastic and oncologic profiles of patients seropositive for type 1

Neurology 72

January 6, 2009

9.

10.

antineuronal nuclear autoantibodies. Neurology 1998;50: 652– 657. Pittock SJ, Kryzer TJ, Lennon VA. Paraneoplastic antibodies coexist and predict cancer, not neurological syndrome. Ann Neurol 2004;56:715–719. Vernino S, Lennon VA. Ion channel and striational antibodies define a continuum of autoimmune neuromuscular hyperexcitability. Muscle Nerve 2002;26:702–707.

MULTIPLE SCLEROSIS AND CANNABIS: A COGNITIVE AND PSYCHIATRIC STUDY

To the Editor: Drs. Ghaffar and Feinstein1 report important new data associating regular smoking of street cannabis in patients with multiple sclerosis (MS) with more extensive cognitive abnormalities compared to patients with MS who do not use cannabis. In 2006 we reported subtle deficits in specific neuropsychological domains in heavy, long-term cannabis users that were in the unintoxicated state.2 The Ghaffar and Feinstein report provides evidence that patients with MS might suffer additional cognitive decline when smoking cannabis regularly.1 However, cognitive deficits that have been attributed to regular recreational use of cannabis are not necessarily extended to controlled pharmaceutical use of cannabis-based medicinal extracts (CBMEs). However, the findings of Ghaffar and Feinsten form the basis on which to raise concern regarding potential cognitive adverse effects of long-term regular cannabis use in MS. We recently reviewed MS clinical trial data of CBMEs and specifically focused on parallel assessments of cognitive status in order to establish whether any disruptive effects on cognition had been documented in these trials.3 Available data indicated that no significant cognitive decline occurs after relatively short-term administration of CBMEs. However, safer and more valid conclusions will have to await the results of long-term, large-scale, systematic clinical trials of CBMEs. In addition, the Ghaffar and Feinstein report did not adjust for premorbid cognitive ability between groups of patients with MS.1 By matching groups on measures of crystallized intelligence that are relatively resilient to brain impairment (i.e., Wechsler Abbreviated Scale of Intelligence [Vocabulary scale] or National Adult Reading Test), groups may be more equal with regard to premorbid cognitive abilities. MS cannabis users reporting greater cognitive deficits may reflect premorbid cognitive impairments rather than consequences of cannabis exposure. Another important limitation of this study1 concerns the potential neurocognitive effects of cannabis withdrawal syndrome. This may have influenced the results as MS cannabis users were noted to have used cannabis 1–30 days before testing.4

Because the study does not provide mean duration of abstinence from cannabis use by patients with MS, we might assume that the findings regarding the more extensive cognitive abnormalities actually reflect acute effects of cannabis on cognition and cannot be certain that these differences would persist after adequate abstinence periods. Despite the important contribution of this new study, the findings should be interpreted within the context of these important caveats. Lambros Messinis, Panagiotis Papathanasopoulos, Patras, Greece Disclosure: The authors report no disclosures.

Reply from the Authors: Drs. Messinis and Papathanasopoulos raise interesting and pertinent questions related to our findings that inhaled cannabis is associated with greater impairment in speed of information processing in patients with MS.1 We agree that this finding may not apply to CBMEs and acknowledged this in our article’s concluding sentence. However, it is still unclear whether the long-term use of pharmaceutically derived CBMEs affects cognitive function, a point made by Drs. Messinis and Papathanasopoulos in their recent comprehensive review.3 Other factors could have influenced cognitive functioning in our sample apart from the use of inhaled cannabis. We did not use the ANART or the vocabulary subscale of the Wechsler Abbreviated Scale of Intelligence to control for premorbid intelligence, but rather relied on the number of years of completed education, which did not differ between our cannabis users and control subjects. We subsequently ran a second analysis which reviewed the possible differences in occupational category (professional and skilled versus other) and again did not find between-group differences (␹2 ⫽ 0.2; p ⫽ 0.0.72; Fisher exact test). While these data are not as robust as those obtained from psychometric measures, they indicate that inhaled cannabis rather than premorbid intellect explains the cognitive findings.

The question of whether the greater cognitive deficits recorded in our cannabis users were influenced by a cannabis withdrawal syndrome is intriguing. In general, while the data supporting the validity of this syndrome appear compelling, it is less clear whether altered cognition is part of the clinical picture. Only one out of 10 studies investigating the clinical picture of cannabis abstinence listed impaired concentration as the sole cognitive complaint,4 leading Budney et al.5 to omit any reference to impaired cognition as part of their suggested criteria for the syndrome. Based on the existing literature, it seems unlikely that the cognitive problems identified in our cannabis smokers are a function of a withdrawal syndrome, but we cannot be certain of this given the limitations in our data. We did not collect information on precisely how much time had elapsed between our subjects smoking cannabis and their completing the neuropsychological battery. As with so much in the field, further research is needed to explore these issues. Anthony Feinstein, Omar Ghaffar, Toronto, Ontario, Canada Disclosure on article to which this Correspondence refers: O.G. has received honoraria from Cerebrio, a continuing medical education company. A.F. has received lecture honoraria from Berlex Canada, Serono Canada, Serono USA, Teva Neuroscience, and Avanir Pharmaceuticals. Copyright © 2009 by AAN Enterprises, Inc. 1.

2.

3.

4.

5.

Ghaffar O, Feinstein A. Multiple sclerosis and cannabis: a cognitive and psychiatric study. Neurology 2008;71: 164 –169. Messinis L, Kyprianidou A, Malefaki S, Papathanasopoulos P. Neuropsychological deficits in long-term frequent cannabis users. Neurology 2006;66:737–739. Papathanasopoulos P, Messinis L, Lyros E, Kastellakis A, Panagis G. Multiple sclerosis, cannabinoids and cognition. J Neuropsychiatry Clin Neurosci 2008;20: 36 –51. Budney AJ, Hughes JR, Moore BA, et al. Review of the validity and significance of cannabis withdrawal syndrome. Am J Psychiatry 2004;161:1967–1977. Budney AJ, Hughes JR. The cannabis withdrawal syndrome. Curr Opin Psychiatry 2006;19:233–238.

Neurology 72

January 6, 2009

101

Section Editors Christopher J. Boes, MD Kenneth J. Mack, MD, PhD

Book Review

PEDIATRIC CLINICAL NEUROPHYSIOLOGY

edited by Karin Edebol Eeg-Olofsson, 156 pp., MacKeith Press for the International Child Neurology Association, 2007, $119.95 This volume provides an invaluable overview and insight into the applicability of various modes of clinical neurophysiology in the practice of pediatric neurology. As stated in the preface, the aim is “to give pediatric neurologists an introduction to clinical neurophysiology and its applications, with special reference to children.” In addition to reviewing maturation of central and peripheral myelination in children, chapters address the techniques of nerve conduction studies, electromyography, evoked potentials, autonomic testing, electroencephalography, and transcranial magnetic stimulation. Authors are from the active and emeritus staff in the Departments of Neuroscience and Women and Children’s Health/Neuropaediatrics of the University Hospital in Uppsala, Sweden. These chapters reflect a wealth of experience and provide insight into the practical aspects of performing these tests, information about normal maturation, identification of technical factors that can affect results, and guidance about clinical applicability.

Two chapters deserve particular mention. The chapter by Erik Stalberg, “The Motor Unit and Electromyographic Methods,” is particularly effective at explaining to clinicians without training in neurophysiologic techniques how the pathophysiologic status of the motor unit can be inferred from observed changes in needle electromyography. In addition, a chapter written by Karin Edebol Eeg-Olofsson on “Transcranial Magnetic Stimulation” provides clear understanding both of the technique and potential clinical applications. (Transcranial magnetic stimulation is not currently approved for clinical use in the United States.) This book does not attempt to serve as a primer to prepare individuals to perform and interpret clinical neurophysiologic tests in children. Instead, it readily meets its goal of educating clinicians with respect to the value, as well as potential limitations, of these techniques as one approaches neurologic symptoms and signs in infants, children, and adolescents. It would be a valuable addition to the library of pediatric neurologists and their departments. Reviewed by Nancy Kuntz, MD, PDN Copyright © 2009 by AAN Enterprises, Inc.

Resident & Fellow Section: Call for Teaching Videos The Neurology® Resident section is featured online at www.neurology.org. The Editorial Team of this section is seeking teaching videos that will illustrate classic or uncommon findings on movement disorders. Such videos will aid in the recognition of such disorders. Instructions for formatting videos can be found in the Information for Authors at www.neurology.org.

102

Neurology 72

January 6, 2009

Calendar

2009 Neurology® publishes short announcements of meetings and courses related to the field. Items must be received at least 6 weeks before the first day of the month in which the initial notice is to appear. Send Calendar submissions to Calendar, Editorial Office, Neurology®, Suite 214, 20 SW 2nd Ave., P.O. Box 178, Rochester, MN 55903 [email protected]

JAN. 16 –18 AAN Winter Conference will be held at Disney Contemporary Resort in Orlando, FL. American Academy of Neurology: tel (800) 879-1960; www.aan.com/winter. FEB. 9 –11 Case Studies in Epilepsy Surgery will be held at the Silver Tree and Snowmass Conference Center in Snowmass, CO. Contact Martha Tobin at (216) 445-3449 or (800) 2232273, ext 53449, or at [email protected] for seminar details. FEB. 9 –13 The 22nd Annual Practicing Physician’s Approach to the Difficult Headache Patient will be held at the Camelback Inn, Scottsdale, AZ. Approved for AMA PRA Category 1 credit. Diamond Headache Clinic Research & Educational Foundation: tel (877) 706-6363 or (733) 883-2062; [email protected]; www.dhc-fdn.org. FEB. 16 –17 Fifth Annual Update Symposium on Clinical Neurology and Neurophysiology will be held in Tel Aviv, Israel. Presented by Weill Cornell Medical College, Department of Neurology, and Tel Aviv University, Adams Brain Supercenter. www.neurophysiology-symposium.com. FEB. 20 –22 International Symposium on Stereotactic Body Radiation Therapy and Stereotactic Radiosurgery will be held at the Floridian Resort & Spa in Lake Buena Vista, FL. Contact Martha Tobin at (216) 445-3449 or (800) 223-2273, ext 53449, or at [email protected] for seminar details. APR. 2– 4 The Innsbruck Colloquium on Status Epilepticus 2009 will be held at the Congress Innsbruck, Austria. [email protected]; www.innsbruck-SE2009.eu. APR. 3 5th Annual Contemporary Issues in Pituitary: Casebase Management Update will be held at the Cleveland Clinic Lerner Research Institute in Cleveland, OH. Contact Martha Tobin at (216) 445-3449 or (800) 223-2273, ext 53449, or at [email protected] for seminar details. APR. 20 –22 Leksell Gamma Knife® Perfexion™ Upgrade Course will be held at the Gamma Knife Center in Cleveland, OH. Contact Martha Tobin at (216) 445-3449 or (800) 2232273, ext 53449, or at [email protected] for seminar details. APR. 25–MAY 2 AAN Annual Meeting will be held in Seattle, Washington State Convention & Trade Center, WA. American Academy of Neurology: tel (800) 879-1960; www.aan.com/am. MAY 3– 6 2nd International Epilepsy Colloquium, Pediatric Epilepsy Surgery Cite´ Internationale will be held in Lyon, France. http://epilepsycolloquium2009ams.fr.

MAY 6 –10 International SFEMG Course and Xth Quantitative EMG conference will be held in Venice, Italy. tel 39041-951112; [email protected]; www.congressvenezia.it. MAY 8 The Office of Continuing Medical Education at the University of Michigan Medical School is sponsoring a CME conference entitled: Movement Disorders: A Practical Approach. It is located at The Inn at St. John’s in Plymouth, Michigan. tel (734) 763-1400; fax (734) 936-1641. MAY 11–12 Music and the Brain will be held at the InterContinental Hotel & Bank of America Conference Center in Cleveland, OH. Contact Martha Tobin at (216) 445-3449 or (800) 223-2273, ext 53449, or at [email protected] for seminar details. MAY 15–17 The Fifth International Conference on Alzheimer’s Disease and Related Disorders in the Middle East will be held in Limassol, Cyprus. www.worldeventsforum.com/alz. MAY 28 –30 6th International Headache Seminary. Focus on Headaches: New Frontier in Mechanisms and Management will be held at the Grand Hotel des Iles Borromees in Stresa (Italy); tel/fax 02 7063 8067; [email protected]. JUN. 8 –12 Leksell Gamma Knife® Perfexion™ Introductory Course will be held at the Gamma Knife Center in Cleveland, OH. Contact Martha Tobin at (216) 445-3449 or (800) 223-2273, ext 53449, or at [email protected] for seminar details. JUN. 12 Mellen Center Regional Symposium on Multiple Sclerosis will be held at the InterContinental Hotel & Bank of America Conference Center in Cleveland, OH. Contact Martha Tobin at (216) 445-3449 or (800) 223-2273, ext 53449, or at [email protected] for seminar details. JUN. 19 –24 Epileptology Symposium will be held at the InterContinental Hotel & Bank of America Conference Center, in Cleveland, OH. Contact Martha Tobin at (216) 445-3449 or (800) 223-2273, ext 53449, or at [email protected] for seminar details. JUL. 7–10 SickKids Centre for Brain & Behaviour International Symposium. [email protected]; www.sickkids.ca/ learninginstitute. JUL. 16 –18 Mayo Clinic Neurology in Clinical Practice2009 will be held at the InterContinental Hotel, Chicago, IL. Mayo CME: tel: (800) 323-2688; [email protected]; http:// www.mayo.edu/cme/neurology-neurologic-surgery.html. SEP. 12–15 13th Congress of the European Federation of Neurological Societies will be held in Florence, Italy. For more information: tel ⫹41 22 908 0488; http://www.kenes.com/efns2009/ index.asp; [email protected]. Neurology 72

January 6, 2009

103

SEP. 25 Practical Pearls in Neuro-Ophthalmology–International Symposium in Honour of Dr. James Sharpe will be held on September 25, 2009 at the University of Toronto Conference Centre, Toronto, Ontario. For further information contact the Office of Continuing Education & Professional Development, Faculty of Medicine, University of Toronto: tel (416) 978-2719; (888) 5128173; fax (416) 946-7028; [email protected]; http:// events.cmetoronto.ca/website/index/OPT0907. OCT. 8 –11 The Third World Congress on Controversies in Neurology. Full information is available at: ComtecMed Med-

ical Congresses, PO Box 68, Tel-Aviv, 61000 Israel; tel ⫹972–35666166; fax ⫹972–3-5666177; [email protected]; www. comtecmed.com/cony. OCT. 24 –30 19th World Congress of Neurology, WCN 2009, will be held in Bangkok, Thailand. www.wcn2009bangkok.com. NOV. 19 –22 The Sixth International Congress on Vascular Dementia will be held Barcelona, Spain. For further details, please contact: Kenes International 17 Rue du Cendrier, P.O. Box 1726, CH-1211, Geneva 1, Switzerland; tel ⫹41 22 908 0488; fax ⫹41 22 732 2850; [email protected]; http://www. kenes.com/vascular.

Save These Dates for AAN CME Opportunities! Mark these upcoming dates on your calendar for these exciting continuing education opportunities, where you can catch up on the latest neurology information. AAN Annual Meetings ● April 25—May 2, 2009, Seattle, Washington State Convention & Trade Center ● April 10 –17, 2010, Toronto, Ontario, Canada AAN Regional Conference ● January 16 –18, 2009, Disney Contemporary Resort in Orlando, FL

104

Neurology 72

January 6, 2009

In the next issue of Neurology® Volume 72, Number 2, January 13, 2009 www.neurology.org THE MOST WIDELY READ AND HIGHLY CITED PEER-REVIEWED NEUROLOGY JOURNAL

THIS WEEK IN Neurology®

105

171

Highlights of the January 13 issue

Cerebral microbleeds are a risk factor for warfarinrelated intracerebral hemorrhage S.-H. Lee, W.-S. Ryu, and J.-K. Roh

EDITORIALS

106

108

Parkinson disease(s): Is “Parkin disease” a distinct clinical entity? Christine Klein and Katja Lohmann

SPECIAL ARTICLES

177

Practice Parameter: Evaluation of distal symmetric polyneuropathy: Role of autonomic testing, nerve biopsy, and skin biopsy (an evidence-based review) J.D. England, G.S. Gronseth, G. Franklin, et al.

185

Practice Parameter: Evaluation of distal symmetric polyneuropathy: Role of laboratory and genetic testing (an evidence-based review) J.D. England, G.S. Gronseth, G. Franklin, et al.

Selection bias in observational studies: Out of control? Christopher A. Beck

ARTICLES

110

A multidisciplinary study of patients with early-onset PD with and without parkin mutations E. Lohmann, et al., The French Parkinson’s Disease Genetics Study Group

117

Comorbidity delays diagnosis and increases disability at diagnosis in MS R.A. Marrie, R. Horwitz, G. Cutter, et al.

125

135

CLINICAL/SCIENTIFIC NOTES

193

Postmenopausal hormone therapy and subclinical cerebrovascular disease: The WHIMS-MRI Study L.H. Coker, et al., for the Women’s Health Initiative Memory Study

Paroxysmal hypothermia as a clinical feature of multiple sclerosis N. Weiss, D. Hasboun, S. Demeret, et al.

195

Postmenopausal hormone therapy and regional brain volumes: The WHIMS-MRI Study S.M. Resnick, et al., for the Women’s Health Initiative Memory Study

HLA class II allele analysis in MuSK-positive myasthenia gravis suggests a role for DQ5 E. Bartoccioni, F. Scuderi, A. Augugliaro, et al.

NEUROIMAGES

A radiologic “alcohol breathalyzer” test S.H. Wong, T. Smith, and R.P. White

143

MRI correlates of cognitive decline in CADASIL: A 7-year follow-up study M.K. Liem, S.A.J. Lesnik Oberstein, J. Haan, et al.

198

149

Surrogate consent for dementia research: A national survey of older Americans S.Y.H. Kim, H.M. Kim, K.M. Langa, et al.

RESIDENT & FELLOW SECTION

156

162

165

␣-Internexin expression identifies 1p19q codeleted gliomas F. Ducray, E. Crinie `re, A. Idbaih, K. Mokhtari, et al.

e5

Clinical Reasoning: A 23-year-old woman with paresthesias and weakness C. Karam, A. Khorsandi, and D.J. MacGowan

CORRESPONDENCE

Visual evoked potentials with CRT and LCD monitors: When newer is not better A.M. Husain, S. Hayes, M. Young, and D. Shah

199

J. Clifford Richardson and 50 years of PSP

200

Reversal of TTH with hypertonic saline

Benefits and risks of stavudine therapy for HIVassociated neurologic complications in Uganda N. Sacktor, N. Nakasujja, R.L. Skolasky, et al.

FUTURE ISSUES

Abstracts In the Next Issue of Neurology姞

Subject to change.

THE OFFICIAL JOURNAL OF THE AMERICAN ACADEMY OF NEUROLOGY