Disturbance of eye movements in Huntington's chorea.

Eye movements were investigated in 14 patients with manifest Huntington's Chorea, 10 offspring and 10 normal subjects with electronystagmography (ENG) and during REM sleep. In choretic patients the following abnormalities were found: 1. Voluntary saccades were slowed in 10 of 14 patients and were more disturbed in the vertical than the horizontal direction. 2. Also, the velocity of the fast phase of optokinetic nystagmus was clearly reduced, especially in the vertical plane. 3. Horizontal, pendular pursuit movements are often superimposed by square wave opposite jerks. 4. Vestibular nystagmus was disturbed, too, especially in the fast phase. 5. During paradoxical sleep, rapid eye movements are less frequent. 6. In ten offspring, eight showed similar oculomotor disturbances.