The Behavioral Neurology of White Matter This page intentionally left blank The Behavioral Neurology of White Matter SECOND EDITION CHRISTOPHER M. FILLEY PROFESSOR OF NEUROLOGY AND PSYCHIATRY DIRECTOR, BEHAVIORAL NEUROLOGY SECTION UNIVERSITY OF COLORADO SCHOOL OF MEDICINE NEUROLOGY SERVICE CHIEF DENVER VETERANS AFFAIRS MEDICAL CENTER AURORA, CO 1 1 Oxford University Press, Inc., publishes works that further Oxford University’s objective of excellence in research, scholarship, and education. Oxford New York Auckland Cape Town Dar es Salaam Hong Kong Karachi Kuala Lumpur Madrid Melbourne Mexico City Nairobi New Delhi Shanghai Taipei Toronto With offi ces in Argentina Austria Brazil Chile Czech Republic France Greece Guatemala Hungary Italy Japan Poland Portugal Singapore South Korea Switzerland Th ailand Turkey Ukraine Vietnam Copyright © 2012 Oxford University Press Published by Oxford University Press, Inc. 198 Madison Avenue, New York, New York 10016 www.oup.com Oxford is a registered trademark of Oxford University Press All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior permission of Oxford University Press. ______________________________________________________________________ Library of Congress Cataloging-in-Publication Data Filley, Christopher M., 1951- Th e behavioral neurology of white matter/Christopher M. Filley. — 2nd ed. p.; cm. Includes bibliographical references and index. ISBN 978-0-19-974326-1 (hardcover) I. Title. [DNLM: 1. Brain Diseases — physiopathology. 2. Brain Diseases — psychology. 3. Behavior — physiology. 4. Brain — physiology. 5. Mental Disorders — physiopathology. 6. Neural Pathways — physiopathology. WL 348] 616.8'047 — dc23 2011044187 ______________________________________________________________________ Th is material is not intended to be, and should not be considered, a substitute for medical or other professional advice. Treatment for the conditions described in this material is highly dependent on the individual circumstances. And, while this material is designed to off er accurate information with respect to the subject matter covered and to be current as of the time it was written, research and knowledge about medical and health issues is constantly evolving and dose schedules for medications are being revised continually, with new side eff ects recognized and accounted for regularly. Readers must therefore always check the product information and clinical procedures with the most up-to-date published product information and data sheets provided by the manufacturers and the most recent codes of conduct and safety regulation. Th e publisher and the authors make no representations or warranties to readers, express or implied, as to the accuracy or completeness of this material. Without limiting the foregoing, the publisher and the authors make no representations or warranties as to the accuracy or effi cacy of the drug dosages mentioned in the material. Th e authors and the publisher do not accept, and expressly disclaim, any responsibility for any liability, loss or risk that may be claimed or incurred as a consequence of the use and/or application of any of the contents of this material. 9 8 7 6 5 4 3 2 1 Printed in the United States of America on acid-free paper For, in the fi rst place, the brain is essentially a place of currents, which run in organized paths. —William James This page intentionally left blank CONTENTS Foreword from the First Edition xi Preface to the First Edition xiii Preface to the Second Edition xv PART ONE Th e Brain, the Mind, and White Matter 1. Th e Neurologic Background 3 White Matter in the History of Neurology 4 Th e Concept of Subcortical Dementia 10 White Matter and Higher Function 12 Th e Perspective of Behavioral Neurology 17 2. White Matter Structure and Function 23 Neuroanatomy 24 Neurophysiology 34 3. Neuroimaging 43 Computed Tomography 43 Magnetic Resonance Imaging 44 Magnetic Resonance Spectroscopy 50 Magnetization Transfer Imaging 51 Diff usion Tensor Imaging 51 Functional Neuroimaging 56 Mapping Neural Networks 58 4. Development and Aging 65 Development of White Matter 65 White Matter Changes in Aging 68 PART TWO Disorders of White Matter 5. Genetic Disorders 81 Leukodystrophies 82 Fragile X Tremor/Ataxia Syndrome 92 viii CONTENTS Aminoacidurias 93 Phakomatoses 95 Mucopolysaccharidoses 98 Muscular Dystrophy 99 Callosal Agenesis 101 6. Demyelinative Diseases 113 Multiple Sclerosis 113 Neuromyelitis Optica 123 Acute Disseminated Encephalomyelitis 124 Schilder’s Disease 125 Marburg’s Disease 126 Balò’s Concentric Sclerosis 126 Tumefactive Multiple Sclerosis 126 7. Infectious Diseases 135 Human Immunodefi ciency Virus Infection 135 Progressive Multifocal Leukoencephalopathy 140 Subacute Sclerosing Panencephalitis 141 Progressive Rubella Panencephalitis 142 Varicella Zoster Vasculopathy 142 Cytomegalovirus Encephalitis 143 Lyme Encephalopathy 143 8. Infl ammatory Diseases 151 Systemic Lupus Erythematosus 151 Behçet’s Disease 155 Sjögren’s Syndrome 156 Wegener’s Granulomatosis 156 Temporal Arteritis 157 Polyarteritis Nodosa 157 Scleroderma 158 Primary Angiitis of the Central Nervous System 158 Sarcoidosis 159 9. Toxic Leukoencephalopathy 163 Radiation 163 Th erapeutic Drugs 167 Drugs of Abuse 169 Environmental Toxins 176 Th e Spectrum of Toxic Leukoencephalopathy 178 CONTENTS ix 10. Metabolic Disorders 187 Cobalamin Defi ciency 187 Folate Defi ciency 190 C entral Pontine Myelinolysis 191 Hypoxia 192 Hypertensive Encephalopathy 194 Eclampsia 195 High-Altitude Cerebral Edema 196 11. Vascular Diseases 201 Binswanger’s Disease 201 Leukoaraiosis 206 Cerebral Amyloid Angiopathy 210 CADASIL 211 Migraine 214 White Matter Disease of Prematurity 215 12. Traumatic Disorders 225 Traumatic Brain Injury 225 Shaken Baby Syndrome 230 Corpus Callosotomy 231 Frontal Lobotomy 233 13. Neoplasms 241 Gliomas 241 Gliomatosis Cerebri 246 Primary Central Nervous System Lymphoma 248 Focal White Matter Tumors 250 14. Hydrocephalus 257 Early Hydrocephalus 257 Hydrocephalus Ex Vacuo 260 Normal Pressure Hydrocephalus 261 PART THREE White Matter and Higher Function 15. Cognitive Dysfunction and Dementia 273 Cognitive Dysfunction 274 White Matter Dementia 278 Why Another Dementia Syndrome? 293