Supranuclear disorders of eye movement.

Eye movements are the result of activity in discrete systems. Saccades and smooth pursuit movements respond to target position and target velocity respectively. Compensatory responses to movements that alter the position of the eyes in space depend upon the vestibular and optokinetic systems. Vergence movements allow fusion and binocular vision. Eye movement abnormalities of supranuclear origin may be divided into nystagmus, other ocular oscillations, saccadic dysfunction, smooth pursuit dysfunction, gaze palsy, tonic deviation, and vergence disability. An algorithm for the analysis of supranuclear eye movement disorders is presented.