["Associative" visual agnosia for objects, pictures, faces and letters with altitudinal hemianopia].
We report a 63-year-old right-handed man with the associative visual agnosia and bilateral altitudinal hemianopia. Neurological examination revealed fair visual acuity and normal ocular movement. Other cranial-nerve, motor, sensory, and autonomic functions were normal. The brain MRI showed multiple infarction involving the right fusiform and lingual gyri extending to the adjacent white matter of the occipito-temporal lobes and posterior part of the parahippocampus, the left fusiform and lingual gyri, and multiple lacunae in bilateral basal ganglia. Cerebral angiography demonstrated occlusion at the P1 portions of bilateral posterior cerebral arteries. 123I IMP-SPECT revealed decreased perfusion in bilateral occipital lobes, worse on the right. Visual evoked fields showed normal pattern of P100 m on bilateral occipital lobes. Neuropsychologically he was alert and oriented in place. In WAIS-R, he could not perform any of performance subtests, while his VIQ was 72. His verbal and visual memory was impaired. His visual perception of forms seemed to be almost preserved. He could copy simple drawing precisely, although he could not recognize the drawing just copied. He could match pictures, letters and photographs of faces. His visual identification of forms, on the other hand, was severely disturbed. He could identify only simple geometrical figures, but not simple drawings such as an apple or the face of his daughter. Reading Kanji was impaired and he read Kana in letter-by-letter manner. Tactile identification of objects was much better than visual one. Naming objects from verbal description was well preserved. Drawing fruits or cars from memory was intact. These data suggests that the present case had fairly good visual perception as was demonstrated by good copying and matching performance, and the case could be classified into the associative type of visual agnosia if the dichotomized classification of apperceptive and associative type is employed. However, closer look at his way of copying clearly showed that he copied in piecemeal fashion, suggesting difficulty in seeing a figure as a dynamic whole. It is possible that fine and precise discrimination of shape and pattern is subserved by the bilateral ventral or occipito-temporal visual system which was compromized in the present case.
Suzuki
K
K
Section of Neuropsychology, Tohoku University Graduate School of Medicine.
Nomura
H
H
Yamadori
A
A
Nakasato
N
N
Takase
S
S
D000377:Agnosia / Q000209:etiology*; D002544:Cerebral Infarction / Q000150:complications*; D005556:Form Perception / Q000502:physiology; D006423:Hemianopsia / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged