This fourth edition of Huntington's Disease presents a comprehensive summary of the current knowledge of this disease, including the major scientific and clinical advances that have occurred since publication of the third edition in 2002. Completely updated and expanded, chapters in this volume are organized in five sections: * Clinical aspects of Huntington's disease, including updated chapters on historical perspectives, neurological, neuropsychiatric, and neuropsychological aspects, and new chapters on juvenile Huntington's and the premanifest and early stages * The genetics of Huntington's disease, including new information on its epidemiology discussions of new testing guidelines * Neurobiology, including recent insights into correlations between pathology and symptoms and a new chapter on neuronal circuitry * The molecular biology of Huntington's disease, including new chapters on the normal function of huntingtin, the molecular pathogenesis of Huntington's disease and the peripheral pathology of the disorder, and an extensively updated chapter on its structural biology * An updated description of the comprehensive care for Huntington's disease, featureing a new chapter on preclinical therapeutics and a completely rewritten chapter on the state of the art of experimental therapeutics and clinical trials.