[Visual memory in a case of topographical disorientation].

A 67-year-old, right-handed man was admitted to our hospital because of restricted field of vision. Neurological examination revealed left upper quadrantanopsia on confrontation. Axial and coronal T2 weighted MR images showed an increased signal intensity lesion that involved the right fusiform and lingual gyri. A small lesion was also noted in the white matter of the left cuneate gyrus. He was unable to describe the ground plan of his house or the well-known route he lived. No signs of unilateral spatial neglect, prosopangnosia, apraxia, and aphasia were found in specific tests. Wechsler Adult Intelligence Scale showed verbal IQ 126 and performance IQ 92. However, he scored poorly in the Benton Visual Retention Test (5 correct immediate recalls from 10 items). Recall from memory of Rey-Osterrieth's complex figure was severely impaired. Visual recall subtest of the Wechsler Memory Scale-Revised (WMS-R) scored 30 points when performed immediately, but zero after a 30 minutes delay. Visual paired associates learning from the WMS-R was also severely impaired. These findings suggest that visual memory is one of the important factors in the pathogenesis of topographical disorientation of this patient.