Huntington disease and other choreas.

Chorea is defined as a syndrome characterized by brief, abrupt involuntary movements resulting from a continuous flow of random muscle contractions. There are genetic and non-genetic causes of chorea. The most common genetic cause of chorea is Huntington's disease (HD). Non-genetic forms of chorea include vascular choreas, auto-immune choreas, metabolic and toxic choreas, and drug-induced choreas. This chapter provides an overview of clinical features, pathogenesis and management of HD, other important genetic causes of chorea, Sydenham's chorea, other autoimmune choreas and vascular choreas.