Persistent chorea as a manifestation of thyrotoxicosis.

We report a case of persistent chorea as a manifestation of thyrotoxicosis. The chorea was severe and persisted after the patient was rendered euthyroid. Dopamine antagonists only partially suppressed the involuntary movements during the first few months. It was eventually controlled with haloperidol, but whenever she discontinues the treatment the chorea has returned during the 16 months since she first presented.