[Visual disturbances following right cerebral lesion: a case report].

A 49-year-old right handed male, who showed three types of visual disturbance, e. g. hemianopsia, obscuration phenomena and unilateral visuospatial agnosia at different times, was reported. At first, he had hemiparesis, hemisensory disturbance and homonymous hemianopsia on the left side because of multiple stenoses of posterior branches of the right middle cerebral artery. His motor and visual field disturbances improved for several days after onset, but there appeared transient obscuration phenomena on the left visual field. CT scan revealed an abnormal low density area in the right temporo-parietal region. At about 4.5 years after the first attack, he again had hemiparesis and homonymous hemianopsia on the left side. Cerebral angiography showed an occlusion of the right middle cerebral artery. Since his paresis was progressive, STA-MCA anastomoses was performed. Hemiparesis was improved, but homonymous hemianopsia remained. Moreover, at about one year after the second attack, left visuospatial agnosia participated in his hemianopsia. Cerebral angiography showed an additional occlusion in the crural segment of the right posterior cerebral artery. CT scan showed a lesion in the right basal ganglia and temporo-parietal lobe. In most cases, unilateral visuospatial agnosia occurs with hemianopsia. But, in this case, these symptoms occurred at different times. This may indicate the differentiation between unilateral visuospatial agnosia and hemianopsia.