Hemichorea as the inaugural symptom of a cerebral hydatid cyst. Report of a case.

A 12-year-old Moroccan girl was admitted for a one-month history of hemicho rea, She had been given a diagnosis of Sydenham's chorea and was on haloper idol and glucocorticoid therapy. She developed intracranial hypertension an d left hemiparesis, which were investigated by computed tomography of the b rain. A cyst typical of hydatid disease was seen in the right temporopariet al area. The hemichorea resolved immediately upon surgical cyst removal and the hemiparesis within ten days. In countries were hydatid disease is ende mic, hydatid cyst should be considered in patients with abnormal movements. Hydatid cyst is a curable cause of abnormal movements affecting half the b ody.