CRC HDBK DYSTONIA PDF

Preface

Dystonia is a neurological condition that first was described as ‘‘dystonia muscularum deformans'' nearly a century ago. Today, we know that dystonia is a movement disorder, typically characterized by an abnormal posture that is caused by a sustained muscle contraction. Given that the recognition of dystonia as a distinct diagnostic category did not occur until the 1970s, it is not surprising that an early, population-based prevalence study estimated that dystonia only affects approximately 24 per million people. However, with the development of botulinum toxin and an increased interest in this disorder, the prevalence of dystonia now is estimated to be nearly 100 times higher, potentially affecting 220 per million people worldwide.

While directed medical treatment began in the 1970s with the application of anticholinergic therapy, treatment of focal dystonia with botulinum toxin has led to a significant increase in the global recognition and research into this condition. Research conducted over the past 40 years has dramatically improved our understanding of dystonia. We now better understand its epidemiology, genetic risk factors, neurophysiology, and neuropathology. These advances have also improved and expanded treatment, not only with four marketed formulations of botulinum toxin, but also with phenol injection, baclofen pump therapy, and deep brain stimulation. These advances have dramatically improved the quality of life of patients affected with this disorder and have led to novel ideas for the investigation and treatment of other neurological disorders.

This volume was written to allow readers to quickly review the most current information regarding the pathogenesis and treatment of dystonia. The purpose of this book is to summarize the known information regarding this disorder and to present practical clinical assessment and treatment approaches.

The Handbook of Dystonia is organized in three basic sections: Epidemiology and Pathogenesis; Signs and Symptoms; and Treatment Options. After a wellrounded introduction, epidemiology and genetic factors are reviewed; these chapters are then followed by discussion regarding neuroanatomy, neurophysiology, neuropathology, and neuroimaging. Clinical descriptions for the idiopathic dystonias are grouped into generalized, cranial, cervical, limb and doparesponsive dystonia, with additional emphasis on other task-specific dystonias, such as musician's and sports-related dystonia. Secondary causes of dystonia are reviewed, with additional chapters on drug-induced and psychogenic presentations. In addition, because of the increasing emphasis on nonmotor symptoms in all areas of movement disorders, a chapter is devoted to this topic.

Treatment of dystonia is divided into four basic categories: medical treatment, botulinum toxin injections, phenol or neurolytic therapy, and surgical intervention. Given the relative importance of botulinum toxin in the treatment of dystonic disorders, three chapters are devoted to this topic. The surgical procedures for dystonia are divided into selective denervation for cervical dystonia and deep brain stimulation for generalized and other types of dystonia.

I would like to thank the contributors to this volume who have participated in bench and clinical research in dystonic disorders and have provided excellent summaries of these topics. I would also like to thank Informa Healthcare, specifically Susan B. Lee, Rick Werdann, Dana Bigelow, and Jinnie Kim, for their support and encouragement in preparing this book.