Sydenham chorea: MR manifestations in two cases.

The acute onset of a unilateral choreiform movement disorder in a child with a recently documented febrile illness or streptococcal pharyngitis is suggestive of Sydenham chorea. The MR manifestations of two clinically corroborated cases of Sydenham chorea are summarized . Increased signal intensity in the corpus striatum contralateral to the patients ' symptomatic side was observed on T2-weighted images. Focal enhancement in the involved head of the caudate was identified after IV administration of gadopentetate dimeglumine. The MR findings correlated with anatomic regions , which have been described to be susceptible to cross reaction with lgG antibodies that are formed in association with streptococcal infection.