Bilateral chorea-ballism associated with hyperthyroidism.

We describe a 50-year-old patient with four episodes of recurrent bilateral chorea-ballism (BCB) and associated hyperthyroidism. Reappearance of BCB, associated with increased serum levels of thyroid hormones and lack of relevant changes on brain computed tomography/magnetic resonance imaging scans, suggested that the involuntary movements were likely due to thyrotoxicosis-induced biochemical changes. Copyright 2004 Movement Disorder Society