Abstract
Visual suppressions of caloric nystagmus was studied in 86 patients with spinocerebellar degenerations in association with other neurotological examinations.
In 16 of the patients, caloric nystagmus was normally suppressed by visual fixation, while in 41 it was not suppressed, and in 19 it was even enhanced by visual fixation. In 10, the influence of visual fixation on caloric nystagmus could not be evaluated because of deficient caloric nystagmus or of disturbance of the quick phase of nystagmus.
The presence of gaze nystagmus and/or rebound nystagmus was closely correlated with the incidence and degree of the disturbance of visual suppression. Also, disturbance in pursuit eye movement, saccadic eye movement and optokinetic nystagmus was related to that of visual suppression. The presence of positional nystagmus or positioning nystagmus, however, was not related to disturbance of visual suppression.
On the basis of our study of visual suppression, the significance of positional and positioning nystagmus tests was considered to be somewhat different from that of other neurotological examinations.
