Sydenham chorea: an update.

To document possible changing characteristics of Sydenham chorea, we reviewed records of 240 patients with this diagnosis who were seen between 1951 and 1976. A dramatic progressive decline in the number of cases was observed. The syndrome occurred mainly in childhood. Female predominance was apparent only after the 10. There was a high femilial incidence for both chorea and rheumatic fever. Most patients had generalized chorea, and fewer than 20% had hemichorea. Dysarthria, probably of extrapyramidal origin, was frequent but neurologic abnormalities other than diffuse encephalopathy were rare. One-third of the patients had coexisting heart disease. Repeat attacks of Sydenham chorea occurred, but the recurrence rate was much less than noted in previous studies.