Optokinetic nystagmus after cerebellar uvulonodulectomy in squirrel monkeys.

After cerebellar uvulondulectomy in squirrel monkeys (Saimiri sciureus), a change occurred in the optokinetic nystagmus, in that there was a slow-phase eye speed decline, at the stimulus speeds above 90 degrees/sec. The difference was statistically significant when pre- and post-ablative comparisons were made. This result supports the usefulness of the optokinetic nystagmus examination to diagnose conditions which involve posterior inferior vermis of vestibulo-cerebellum. The optokinetic after-nystagmus depicted a similar decline postoperatively.