Preface

Intense medical and scientific interest in an increasing number of topics in sleep medicine has led to the production of this volume on Parasomnias and Other Sleep-Related Movement Disorders. Although parasomnias are ubiquitous in childhood and occur across all ages, this is the first publication to focus on this topic in detail. There is growing recognition that sleep disorders represent a major public health concern, and understanding the basic, translational, clinical and psychosocial aspects of sleep disorders is essential to the process of becoming a skilled clinical practitioner. The earliest reported descriptions of some of the parasomnias such as sleepwalking and nightmares have been known since antiquity; however, new parasomnias have been described, such as REM sleep behavior disorder and catathrenia. There have been numerous developments in the field of abnormal movement disorders during sleep that have led to a better understanding of the clinical features, the diagnostic criteria and subsequently, treatments. These developments have continually deepened our understanding of parasomnias as pathophysiological conditions and have also drawn attention to the impact on the lives of those who have these conditions. Parasomnias can be severe, chronic, debilitating and disabling neurological disorders, often having early age of onset. They frequently involve abnormal involuntary behaviors during sleep, leading to injuries, emotional distress and even medico-legal liability. Despite their prominent symptoms and impact on patients' health-related quality of life, parasomnias remain under-recognized and under-appreciated disorders, perhaps because of their predominantly night-time occurrence.