Myotonic dystrophy, 3rd edition

Myotonic dystrophy, 3rd edition

Book Reviews Myotonic Dystrophy, 3rd Edition By P.S. Harper. 448 pp. Philadelphia: WB Saunders, 2001. $85.00. ISBN 0-7020-2152-0. In the past few year...

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Book Reviews Myotonic Dystrophy, 3rd Edition By P.S. Harper. 448 pp. Philadelphia: WB Saunders, 2001. $85.00. ISBN 0-7020-2152-0. In the past few years there have been monumental advances in our understanding of myotonic dystrophy, especially with respect to its identification as one of the trinucleotide repeat disorders. This fact had not been known at the time of the publication of the first two editions of the book, therefore making a third edition a mandatory and welcomed addition to the medical literature. As a Professor of Medical Genetics in Cardiff, Wales, Peter Harper has had a long-standing interest in this extremely intriguing, variable, and relatively common autosomal-dominant disorder, potentially involving virtually all systems of the body. Only recently has there been an explanation for this variability and multisystem involvement. Harper has organized this edition to provide not only neurologists and child neurologists who care for many of these patients and their families but also other specialists and family practitioners who are involved with their management, with encyclopedic information concerning the cardiorespiratory, anesthetic, ophthalmologic, genetic, and every other problem encountered in this disorder. A separate chapter written by geneticists provides detailed molecular information for interested readers. New information is also provided on proximal myotonic dystrophy and so-called myotonic dystrophy, type 2. Of special interest to child neurologists, in addition to the lucid descriptions of the varying clinical features of myotonic dystrophy, is the specific chapter concerning this disorder in infancy and childhood. Harper emphasizes that diagnosis is unfortunately overlooked in the neonate because of the absence of clinical myotonia, which may not be observed or identified by electromyography until the childhood years, and the fact that diagnosis in a mildly affected parent, almost invariably the mother, may be overlooked. Based on his own clinical experience, he lists facial weakness, delayed motor development, mental retardation, hypotonia, talipes (club feet), neonatal respiratory distress, neonatal feeding difficulties, hydramnios and reduced fetal movements as major features of the congenital form of myotonic dystrophy, although each of the elements is not necessarily present in every case. I find it surprising that he does not list the fact that some infants with the congenital form have a depressed level of consciousness, a finding that often can be confusing to neonatologists. He describes the difference between the congenital form and so-called childhood-onset myotonic dystrophy, differences based on the number of trinucleotide repeats present, with the congenital form having large numbers of repeats and the childhood form fewer numbers of repeats. Harper has personally followed large numbers of children with myotonic dystrophy and describes the clinical course and complications in detail. He points out an important feature that, despite the severe hypotonia and club feet, most of the children will learn to walk independently, although slowly. Harper points out some of the important features in the differential diagnosis of the hypotonic infant. These include some of the congenital myopathies, such as nemaline myopathy and central core disease and the X-linked form of myotubular myopathy, congenital myasthenic syndromes, Mo¨bius syndrome, anoxic brain damage, metabolic cerebral degeneration, and spinal muscular atrophy, type I. He also points out that although the names congenital myotonic dystrophy and myotonia congenita sound similar they are two totally different entities. To establish a diagnosis of myotonic dystrophy, molecular analysis for the trinucleotide repeat is the gold standard. Harper points out, correctly, that electromyography and muscle biopsy are no longer necessarily part of the evaluation. The unstable nature of the expansion explains the anticipation observed in this disorder, that is, with successive generations the clinical involvement begins at an earlier age and is more severe. Despite this knowledge, Harper points out many unanswered questions in this disease. Of interest he quotes papers maintaining virtual absence of myotonic dystrophy in African populations; in the United States this is certainly not true for black individuals.



Vol. 27 No. 1

In a chapter in which genetic counseling and application of molecular genetics in myotonic dystrophy is clearly detailed, Harper describes practical and ethical considerations with some concentration on issues related to clinical testing in presymptomatic individuals. There may be some differences in the approach in the United Kingdom and the United States based on medicolegal issues so problematic here. In his chapter on management, Harper provides a special section on the management of myotonic dystrophy in infancy and children in addition to his detailed description of the management of adults. He points out the unfortunate lack of a specific medical therapy. He emphasizes that drug treatment geared toward lessening the myotonia is usually disappointing. Likely after the book was printed, modafinil, a medication that is effective in relieving the abnormal daytime sleepiness so common in myotonic dystrophy, became available. This edition is a splendid and timely addition to the medical literature. It not only is of interest to all clinicians who care for patients with myotonic dystrophy, which includes virtually all disciplines of medicine, but it makes interesting reading about a new class of disorders, the trinucleotide repeat diseases, the numbers of which are increasing rapidly. The references are all-encompassing, and the index is a pleasure to use. Alfred J. Spiro Professor of Neurology and Pediatrics Director, MDA Muscle Disease Clinic Albert Einstein College of Medicine

Bronx, NY

Febrile Seizures Edited by Tallie Z. Baram, MD, PhD and Shlomo Shinnar, MD, PhD. 338 pp., illustrated. San Diego: Academic Press, 2002. ISBN: -12-078141-7 This is a wonderful book. The editors and contributors are to be congratulated for compiling such a useful monograph. As the editors indicate in the preface, it has been 20 years since the last comprehensive volume on febrile seizures and much has been learned in the interim, both regarding the clinical and basic science aspects. This is a comprehensive up-to-date book with excellent references that are current and include many citations from 2001. The book is 338 pages, including the index. In addition to the two editors, both of whom are widely recognized for their contributions to the body of knowledge regarding febrile seizures, there are 33 additional contributors, all of whom are also recognized for their expertise. Despite this being a multi-authored text, the chapters are consistently well written. There are a total of 22 chapters divided into seven parts: Part I: Epidemiology of Febrile Seizures, Part II: Patient Studies on the Outcome of Febrile Seizures, Part III: Do Prolonged Febrile Seizures Cause Acute Neuronal Injury?, Part IV: The Neurobiology of Febrile Seizures and of Their Consequences: Experimental Approaches, Part V: Genetics of Febrile Seizures, Part VI: Current Management of Febrile Seizures, and Part VII: Current State of the Art: Implications for Future Study and Treatment. There are slight overlaps among the chapters, although this is kept to a minimum. Approximately one third of the book is devoted to studies using experimental models, particularly those related to febrile seizures in the developing brain and some discussion of other types of seizures. The mechanisms and differences between seizures in the developing brain and the mature brain are contrasted and compared. Thus there is material that is relevant for people with clinical focus, as well as for the basic scientist. Both aspects are state-of-the-art and provide the reader with a balanced viewpoint and a quick access to a thorough and current bibliography. Each chapter is a comprehensive discussion of the topic. Preceding each chapter is a brief summary, much like an abstract of a journal article, except that it contains a synthesis of the material in the chapter rather than the results of an individual study. There may be some of the author’s biases in the summary although the chapters themselves are always well balanced and discuss studies with divergent conclusions so that the reader

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