Sydenham’s chorea (SC) is a self-limiting disorder most often seen in children from 5 to 15 years of age. It may also manifest during pregnancy. This disease is often linked with rheumatic fever and is marked by involuntary movements that can become severe enough over time to affect all motor activities. Sydenham’s chorea is also known as St. Vitus’ dance and rheumatic chorea.

The frequency of SC is related to the incidence of rheumatic fever. SC is estimated to occur in 10% to 20% of patients with rheumatic fever. In the United States, the incidence of rheumatic fever is 0.5:100,000 to 2:100,000. The incidence of SC would be estimated to be about 0.05:100,000 to 0.4:100,000. Internationally, the incidence of rheumatic fever is much higher in developing and underdeveloped countries where antibiotic treatments are much less available. Therefore the incidence of SC is higher in these countries.

The underlying cause of SC is infection by the Lancefield group A β-hemolytic streptococcal organism, which apparently contributes to the development of antineuronal antibodies. The antineuronal antibodies cross-react with an unknown epitope in basal ganglia neurons.