Walsh & Hoyt: Ocular Motor Syndromes Caused by Lesions in the Cerebellum

Clinicians are appropriately cautious in attributing eye movement abnormalities specifically to cerebellar dysfunction, because the brain stem is so frequently damaged in patients with lesions of the cerebellum. Likewise, brain stem lesions can produce a ""functional"" cerebellar lesion and corresponding cerebellar eye signs by virtue of a change in the climbing fiber activity projecting to cerebellar Purkinje cells, as occurs in Wallenbergs syndrome. Holmes and Cogan, however, recognized specific cerebellar eye signs, and Daroff listed more than 30 ""cerebellar eye signs"" in a compendium published in 1982. Recent clinical and experimental studies provide additional evidence that cerebellar lesions alone can cause specific ocular motor abnormalities. In essence, three principal syndromes can be identified: the syndrome of the dorsal vermis and underlying posterior fastigial nuclei, the syndrome of the flocculus and paraflocculus, and the syndrome of the nodulus and ventral uvula.