Sydenham's chorea.

Sydenham's chorea (SC) is a disorder of the central nervous system (CNS) characterized by sudden, involuntary, arrhythmic, clonic, and purposeless movements. SC appears to provide a model for understanding various neuropsychiatric dysfunctions. Its relationship with attentional deficits, obsessive-compulsive symptoms (OCS) as well as movement disorders provides support for the hypothesis of the involvement of the corticostriatal loops in the pathophysiology of the disorder.