The Japanese journal of neuropsychology

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ArticleTitle	Studies on visuospatial memory in a patient with topographical disorientation due to right retrosplenial lesion
Language	J
AuthorList	Hiromi Kuroki, Kazumi Kawahira, Atsuko Ogata, Manabu Kawatsu, Nobuyuki Tanaka
Affiliation	Department of Rehabilitation and Physical Medicine, Kagoshima University Hospital
Publication	Japanese Journal of Neuropsychology: 20 (3), 177-184, 2004
Received	Apr 8, 2003
Accepted	May 24, 2004
Abstract	A 62-year-old ambidextrous male was reported with topographical disorientation and left sided hemianopsia. The CT and MRI showed the infarction in the right posterior lobe including the retrosplenial region. He could not navigate and draw maps of his house, town and rooms of the admitted hospital. He was unable to memorize the position of the goods in the room. Reconstruction of the block designs and spatial arrangements of the pictures of the walking path were also disturbed. Although copy drawing, memories of objects and distinction of landmarks and time orientation were fully spared, his verbal memories were moderately reduced. These results demonstrated that the most remarkable disturbance in this patient was the visuospatial memories rather than that of verbal memories. The topographical disorder in this patient was considered to be derived from the disconnection between the parietal lobe and the right hippocampus-para hippocampus due to a right retrosplenial lesion. Moderate recovery of the verbal memories was considered to occur as a result of the activation of the tract to the left hippocampus due to the innate ambidexterity.
Keywords	topographical disorder, retrosplenial lesion, visuospatial memory, visual processing, hippocampus