[Study of the evoked potentials to photic stimulation in man after deafferentiation of the visual cortex]

A study was made of evoked potentials (EP) in response to light stimulus in the occipital areas of the cortex in 28 patients with homonimous hemianopsia caused by focal affection of the optic system. EP asymmetry in the hemispheres was recorded only in case of complete homonimous hemianopsia. Reduction of response at the side of contralateral hemoanopsia was observed in affection of the optic tracts at the level of the optic cord and in case of spread of the pathological focus to the occipital lobe. In half of the cases of homonimous hemianopsia caused by affection of the optic radiation the responses were greater by amplitude at the side of the focus or were recorded only in the deafferentated occipital area.