Abstract
Mono-ocular DC-recordings of horizontal and vertical eye movements were performed to clarify the influence of eye closing on vestibular nystagmus.
Eyes were elevated 55±11° upwards and adducted 13±5° by closing the eyes. During eye-closure, three types of vertical eye positions were seen in 24 normal adults; 1) holding eye position upwards, 2) fluctuating movements around an elevated eye position, 3) gradual downward turning.
Caloric nystagmus, per-and post-rotatory nystagmus and spontaneous nystagmus caused by inner ear diseases, that is, vestibular nystagmus is suppressed by closing eyes. This suppression depends on the degree of eye-ball elevation. The suppression of vestibular nystagmus caused by eye-closure is the strongest when the eyes are held upwards and released by turning down from the elevated eye position.
