Oculomotor abnormalities in patients with cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS) reflect midline cerebellar impairment

Cerebellar oculomotor dysfunction affected mainly smooth pursuit and gaze holding function at eccentric gaze positions, but it did neither comprise spontaneous nystagmus nor saccade abnormalities. Prolonged latencies in initial pursuit acceleration might be related to the patient's cognitive decline, but normal saccade latencies point to cerebellar oculomotor neurodegeneration. Smooth pursuit impairment was not related to disease duration and vestibulopathy, contrariwise pursuit impairment became worse with larger functional impairment. Oculomotor abnormalities in CANVAS are in line with midline cerebellar impairment without evidence for extracerebellar (brainstem) brain involvement.