The mechanism of inhibition of caloric nystagmus by eye closure.
24 normal adults and 324 clinical cases were examined, for the purpose of shedding light on the mechanism of inhibition of caloric nystagmus by eye closure. When the eyes were closed, an eye was suddenly adducted 13 +/- 5 degrees and elevated 55 +/- 11 degrees. These adductive and upward eye movements were normal responses caused by eye closure. Caloric nystagmus was inhibited by upward eye deviation. With the turning down of the vertical eye position, the caloric-nystagmus inhibition was released. During eye closure, there were four types of vertical eye-movement responses: (a) holding the eye position up, (b) fluctuation around an upward eye position, (c) gradual downward turning, (d) sudden downward turning, Types a, b and c were seen in normal subjects. However, type d was not seen in normal people.
D002150:Caloric Tests; D005133:Eye Movements; D006801:Humans; D014724:Vestibular Function Tests