HORIZONTAL EYE-MOVEMENT DISORDERS AFTER POSTERIOR VERMIS INFARCTIONS

The horizontal saccade, smooth pursuit, and vestibule-ocular reflex ga ins were recorded in 19 patients with cerebellar infarction documented with MRI, and in a group of control subjects. Bilateral saccade hypom etria and a decrease in ipsilateral smooth pursuit gain were found onl y in patients with a lesion affecting the posterior vermis. These resu lts in humans support experimental findings suggesting that the poster ior vermis controls both saccade accuracy and smooth pursuit velocity.