Optic ataxia: Clinical-radiological correlations with the EMlscan

Abstract

After coronary by-pass surgery, a 47 year old, right-handed man developed a Gerstmann's syndrome, a visual-spatial perceptual deficit, and a gross impairment of movement under visual guidance ('optic ataxia'). Visual fields and extraocular movements were intact; he had a left hemiparesis. The EMIscan showed three lesions: a left parietal-occipital lesion; a posterior callosal lesion, and a right frontal lesion. It is hypothesized that optic ataxia in both visual fields requires bilateral lesions which, in the present case, were strategically placed so as to effectively disconnect motor cortex from visual input.