Huntington's Disease.

Huntington's disease is a neurodegenerative disorder inherited in an autosomal dominant fashion that results in involuntary movements, psychiatric symptoms, and cognitive dysfunction. The illness typically begins in midlife and progresses over 15 to 20 years, producing increasing disability. The diagnosis of Huntington's disease in an individual has implications for family members as well, whose at-risk status may be altered by the diagnosis. Genetic counseling and information about alternative approaches (eg, clinical diagnosis, DNA banking) should be provided and consent obtained before DNA testing in a symptomatic patient. Genetic counseling is essential for predictive testing in asymptomatic at-risk individuals. Although disease-modifying therapy is not yet available, a multidisciplinary approach to both pharmacologic and nonpharmacologic management can improve the motor and psychiatric symptoms of the illness and enhance function and quality of life for patients and their families. There have been few rigorous trials of treatments for Huntington's disease. The medications discussed in this article have been empirically found to be useful in the management of specific symptoms. Therapy for the movement disorder should focus on those symptoms that specifically limit function. The potential contribution of medication side effects to disability should be periodically reassessed and therapy adjusted as the disease progresses. Psychiatric symptoms are a substantial source of morbidity in this disorder and should be actively treated because they are often quite responsive to appropriate therapy. Both the motor and the psychiatric symptoms can be modified by environmental as well as pharmacologic strategies. Ongoing assessment of the need for adjunctive therapies by means of physical, occupational, and speech therapy is an important component of management, and social work intervention is often necessary to assist with the practical difficulties faced by patients and caregivers. Voluntary organizations are an important source of information and support for professionals caring for patients with Huntington's disease as well as for patients and their families.