Progressive MRI abnormalities in late recurrence of Sydenham's chorea.

We report four cases of adult recurrence of Sydenham's chorea (SC). The first episodes all followed childhood tonsillopharyngitis. Many years later, subsequent episodes appeared after the triggering circumstances: throat or cutaneous infection, pregnancy, childbirth, contraceptive treatment or stress. Other inflammatory diseases were ruled out and streptococcal serology was weakly positive. Magnetic Resonance Imaging (MRI) revealed focal areas of T2 hypersignal in the caudate nucleus, the pallidum, the putamen and the white matter. One year later, repeat MRI variously gave evidence of the persistence, disappearance or even new appearance of abnormalities. Specific features of SC recurrence in the adult may include: a personal history of chorea after a throat infection during childhood; a second episode of isolated chorea with or without slight neuropsychological disorders; streptococcal serology weakly positive; focal hypersignals involving the basal ganglia; the triggering circumstances. Since SC is considered to be an autoimmune disease, the progressive MRI abnormalities suggest that certain circumstances may trigger the reactivation of persistent immune disorders.