Abnormal eye movements in three types of chorea.

Chorea is an abnormal movement characterized by a continuous flow of random muscle contractions. This phenomenon has several causes, such as infectious and degenerative processes. Chorea results from basal ganglia dysfunction. As the control of the eye movements is related to the basal ganglia, it is expected, therefore, that is altered in diseases related to chorea. Sydenham's chorea, Huntington's disease and neuroacanthocytosis are described in this review as basal ganglia illnesses that can present with abnormal eye movements. Ocular changes resulting from dysfunction of the basal ganglia are apparent in saccade tasks, slow pursuit, setting a target and anti-saccade tasks. The purpose of this article is to review the main characteristics of eye motion in these three forms of chorea.