Psychosis following acute Sydenham's chorea.

Sydenham's chorea (SC) is characterized by motor, mainly choreic involuntary movements, and psychiatric symptoms, including anxiety, depression, obsessive-compulsive and attention-deficit/hyperactivity disorders. Symptoms of SC may be considered as the result of basal ganglia dysfunction determined by autoimmune mechanisms elicited by streptococcal infection. We report on a case of a 13-year-old boy with brief psychotic episode following acute SC. His hallucinations and delusions remitted after treatment with risperidone, paralleling motor improvement. The neurobiological basis of psychotic symptoms remains largely elusive. This case report provides further insight about the involvement of basal ganglia dysfunction on psychosis.