RESUMO
The incidence of sporadic chorea among general hospital admissions is unknown, and the relation of clinical manifestations and etiological factors to neuroimaging findings has been little investigated in this condition. We reviewed the 7,829 cases admitted to the neurology departments of two general hospitals over 3.25 years and identified 23 (8 male and 15 female) cases of apparently sporadic chorea. Analysis of the records of these patients permitted etiological classification as follows: drug-induced chorea (5 patients), vascular chorea (6 patients), chorea-vasculitis (1 patient), Sydenham's chorea (1 patient), AIDS-related chorea (5 patients) and in 4 patients neither etiological factors nor neuroradiological alterations were found. Finally in 1 patient, the genetic test for Huntington's disease was positive. Thirteen patients had pathological neuroimaging findings; however, in only 3 were basal ganglia lesions considered to be the cause of the chorea. We conclude that sporadic chorea is not rare among neurological department admissions (we found 2.94 cases per 1,000 admissions) and only in a minority of cases is the symptomatology attributable to gross basal ganglia lesions; HIV infection is an emerging cause of chorea.