Oculomotor abnormalities after labyrinthine and cerebellar lesion. A case report

A subject presenting a rare association of left labyrinthine and left hemispheric cerebellar lesion was examined, with recording and analysis of eye movements at different intervals. A complete compensation of the vestibular deficit and recovery of cerebellar postural ataxia, with persistence of limb incoordination and oculomotor abnormalities, were observed. The saccadic, smooth pursuit and optokinetic nystagmus systems were impaired. Ocular signs, in combination, may suggest a cerebellar dysfunction but they do not supply sufficient diagnostic criteria for localizing the cerebellar damage. Only the direction-specific impairment of smooth pursuit and optokinetic nystagmus is indicative of the side of the lesion.