EVALUATION AND TREATMENT OF MYOPATHIES Second Edition SERIES EDITOR Sid Gilman, MD, FRCP William J. Herdman Distinguished University Professor of Neurology University of Michigan Contemporary Neurology Series 69 PALLIATIVE CARE IN NEUROLOGY 77 CLINICAL NEUROPHYSIOLOGY Raymond Voltz, MD, James L. Bernat, MD, OF THE VESTIBULAR SYSTEM Gian Domenico Borasio, MD, DipPallMed, Fourth Edition Ian Maddocks, MD, David Oliver, FRCGP, Robert W. Baloh, MD, FAAN, and and Russell K. Portenoy, MD Kevin A. Kerber, MD 70 THE NEUROLOGY OF EYE 78 THE NEURONAL CEROID MOVEMENTS LIPOFUSCINOSES (BATTEN DISEASE) Fourth Edition Second Edition R. John Leigh, MD, FRCP and David Sara E. Mole, PhD, Ruth D. Williams, MD, S. Zee, MD and Hans H. Goebel, MD, Editors 71 PLUM AND POSNER’S DIAGNOSIS 79 PARANEOPLASTIC SYNDROMES OF STUPOR AND COMA Robert B. Darnell, MD, PhD, and Jerome Fourth Edition B. Posner, MD Jerome B. Posner, MD, Clifford B. Saper, 80 JASPER’S BASIC MECHANISMS MD, PhD, Nicholas D. Schiff, MD, and OF THE EPILEPSIES Fred Plum, MD Jeffrey L. Noebels, MD, PhD, Massimo Avoli, 72 PRINCIPLES OF DRUG THERAPY MD, PhD, Michael A. Rogawski, MD, IN NEUROLOGY PhD, Richard W. Olsen, PhD, Antonio Second Edition V. Delgado-Escueta, MD Michael V. Johnston, MD, and Robert 81 MYASTHENIA GRAVIS AND A. Gross, MD, PhD, Editors MYASTHENIC DISORDERS 73 NEUROLOGIC COMPLICATIONS Second Edition OF CANCER Andrew G. Engel, MD Second Edition 82 MOLECULAR PHYSIOLOGY AND Lisa M. DeAngelis, MD, and Jerome METABOLISM OF THE NERVOUS B. Posner, MD SYSTEM 74 NEUROLOGIC COMPLICATIONS Gary A. Rosenberg, MD OF CRITICAL ILLNESS 83 SEIZURES AND EPILEPSY Third Edition Second Edition Eelco F. M. Wijdicks, MD, PhD, FACP Jerome Engel, Jr., MD, PhD 75 CLINICAL NEUROPHYSIOLOGY 84 MULTIPLE SCLEROSIS Third Edition Moses Rodriguez, MD, Orhun Jasper R. Daube, MD, and Devon I Rubin, H. Kantarci, MD, Istvan Pirko, MD MD, Editors 85 FRONTOTEMPORAL DEMENTIA 76 PERIPHERAL NEUROPATHIES Bruce L. Miller, MD IN CLINICAL PRACTICE 86 AUTONOMIC NEUROLOGY Steven Herskovitz, MD, Stephen Eduardo E. Benarroch, MD N. Scelsa, MD, and Herbert H. Schaumburg, MD EVALUATION AND TREATMENT OF MYOPATHIES Second Edition Edited By Emma Ciafaloni, MD Associate Professor of Neurology and Pediatrics University of Rochester School of Medicine and Dentistry Department of Neurology Rochester, New York Patrick F. Chinnery, FRCP, FMedSci Director, Institute of Genetic Medicine Newcastle University Newcastle upon Tyne, UK Robert C. Griggs, MD Professor of Neurology, Medicine, Pediatrics, Pathology and Laboratory Medicine, Center for Human Experimental Therapeutics University of Rochester School of Medicine and Dentistry Department of Neurology Rochester, New York 1 1 Oxford University Press is a department of the University of Oxford. It furthers the University’s objective of excellence in research, scholarship, and education by publishing worldwide. 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 offices in Argentina Austria Brazil Chile Czech Republic France Greece Guatemala Hungary Italy Japan Poland Portugal Singapore South Korea Switzerland Thailand Turkey Ukraine Vietnam Oxford is a registered trademark of Oxford University Press in the UK and certain other countries. Published in the United States of America by Oxford University Press 198 Madison Avenue, New York, NY 10016 © Oxford University Press 2014 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, without the prior permission in writing of Oxford University Press, or as expressly permitted by law, by license, or under terms agreed with the appropriate reproduction rights organization. Inquiries concerning reproduction outside the scope of the above should be sent to the Rights Department, Oxford University Press, at the address above. You must not circulate this work in any other form and you must impose this same condition on any acquirer. Library of Congress Cataloging-in-Publication Data Evaluation and treatment of myopathies / edited by Robert C. Griggs, Emma Ciafaloni, Patrick F. Chinnery. — Second edition. p. ; cm. Preceded by Evaluation and treatment of myopathies / Robert C. Griggs, Jerry R. Mendell, Robert G. Miller. c1995. Includes bibliographical references and index. ISBN 978–0–19–987393–7 (alk. paper) I. Griggs, Robert C., 1939– editor of compilation. II. Ciafaloni, Emma, editor of compilation. III. Chinnery, Patrick F., editor of compilation. IV. Griggs, Robert C., 1939– Evaluation and treatment of myopathies. Preceded by (work): [DNLM: 1. Muscular Diseases—diagnosis. 2. Muscular Diseases—therapy. WE 550] RC925 616.7′44—dc23 2013039999 The science of medicine is a rapidly changing field. As new research and clinical experience broaden our knowledge, changes in treatment and drug therapy occur. The author and publisher of this work have checked with sources believed to be reliable in their efforts to provide information that is accurate and complete, and in accordance with the standards accepted at the time of publication. However, in light of the possibility of human error or changes in the practice of medicine, neither the author, nor the publisher, nor any other party who has been involved in the preparation or publication of this work warrants that the information contained herein is in every respect accurate or complete. Readers are encouraged to confirm the information contained herein with other reliable sources, and are strongly advised to check the product information sheet provided by the pharmaceutical company for each drug they plan to administer. 9 8 7 6 5 4 3 2 1 Printed in the United States of America on acid-free paper Emma Ciafaloni would like to dedicate this book to Nicholas. And to her patients, who teach her every day, not only about muscle diseases, but about life. Patrick Chinnery dedicates this textbook to Rachel, Sarah, Catherine, Lucy, James, Arthur and Jasper. Berch Griggs dedicates the textbook to his wife Rosalyne. Contents Foreword xiii Preface xv Contributors xvii SECTION 1 APPROACH TO THE Patient WITH MUSCLE DISEASE 1. STRUCTURE AND FUNCTION OF NORMAL MUSCLE 3 Robert C. Griggs THE MOTOR UNIT 3 MUSCLE FIBER TYPES 4 Neural Control of Muscle Fiber Type • Activation of Motor Units According to Muscle Fiber Type Voluntary CONTROL OF MOTOR UNIT ACTIVITY 6 Relationship of Size to the Recruitment of Single Motor Units • Firing Rates of Single Motor Units • Impaired Voluntary Control of Motor Units MUSCLE STRUCTURE AND FUNCTION 7 2. EVALUation OF THE Patient WITH MYopatHY 14 Robert C. Griggs and Emma Ciafaloni INTRODUCTION 15 DEFINITION OF Myopathy 15 The Hereditary Myopathies • The Inflammatory Myopathies • Myopathies Due to Systemic Diseases CLINICAL Evaluation 18 History • Paresthesias and Dysesthesias • Examination • General Examination DIFFERENTIAL DIAGNOSIS 28 Disorders Presenting at Birth With Hypotonia • Disorders Presenting in Infancy • Disorders Presenting in Childhood With Progressive Proximal Weakness • Disorders Presenting in Adulthood Laboratory Evaluation 35 Blood Studies • Urine Studies • Muscle Imaging Procedures ELECTRODIAGNOSIS 39 The Technique of Electromyography • Abnormal Spontaneous Activity • Voluntary Activity • Quantitative Electromyography • Electrical Stimulation Tests: Nerve Conduction Studies • Repetitive Nerve Stimulation vii viii Contents MUSCLE BIOPSY 49 Indications for Biopsy • Selection of Biopsy Sites • Tissue Removal and Preparation • Histologic Techniques • Differentiating Neuropathy From Myopathy • Preferential Fiber Type Involvement • Sources of Diagnostic Error Nerve BIOPSY 57 Indications for Biopsy • Selection of Biopsy Sites • Tissue Removal and Preparation 3. GENETIC EVALUation OF THE Patient AND FAMILY 60 Gerald Pfeffer and Patrick F. Chinnery CLINICAL Evaluation 61 Clinical History • Physical Examination • Clinical Investigations Guiding Genetic Testing MOLECULAR GENETIC TESTING IN A CLINICAL CONTEXT 62 Conventional Genetic Testing • Next-Generation Sequencing Implications OF A POSITIVE GENETIC TEST Result 64 Diagnostic Testing for Affected Family Members • Predictive Testing for Unaffected Family Members • Prenatal Diagnosis • Personalized or Precision Medicine SECTION 2 SPECIFIC MYOPATHIES 4. THE MUSCULAR DYSTROPHIES 69 Emma Ciafaloni and Robert C. Griggs DUCHENNE AND BECKER MUSCULAR DYSTROPHIES 70 Epidemiology • Genetics of Duchenne and Becker Muscular Dystrophies • Carrier Detection and Prenatal Testing • Clinical Features: DMD • Clinical Features: Becker Muscular Dystrophy • Differential Diagnosis • Diagnosis and Tests • Treatment • Other Drugs and Supplements • Respiratory Care • Perioperative Management • Cardiac Care • Bone Health and Orthopedic Management • Nutrition • Physical Therapy • Speech, Cognitive, and Behavioral Management • Palliative Care • Therapies Under Investigation Emery-DREIFUSS MUSCULAR DYSTROPHY 82 Genetics • Clinical Features • Laboratory Features and Diagnostic Tests • Differential Diagnosis • Treatment THE MYOTONIC MUSCULAR DYSTROPHIES 86 Genetics • Clinical Features • Laboratory Features and Diagnostic Tests • Differential Diagnosis • Treatment • Future Directions FACIOSCAPULOHUMERAL MUSCULAR DYSTROPHY 92 Genetics • Clinical Features • Laboratory Features and Diagnostic Tests • Differential Diagnosis • Treatment LIMB-GIRDLE MUSCULAR DYSTROPHIES 96 Genetics • Clinical Features • Laboratory Features and Diagnostic Tests • Differential Diagnosis • Treatment