ASSOCIATIVE VISUAL AGNOSIA AND ALEXIA WITHOUT PROSOPAGNOSIA

Disagreement over the neuroanatomical substrate of associative visual agnosia encompasses such basic issues as: (1) the necessity for bilate ral lesions; (2) the intrahemispheric locus of damage; and (3) the rol es of disconnection versus cortical damage. We examined three patients whose associative visual agnosia encompassed objects and printed word s but spared faces. CAT scans revealed unilateral dominant occipitotem poral strokes. CAT scans of four previously reported cases with this s ame profile of associative agnosia were obtained. Dominant parahippoca mpal, fusiform and lingual gyri were the most extensively damaged cort ical regions surveyed and were involved in all cases. Of white matter tracts surveyed, only temporal white matter including inferior longitu dinal fasciculus was severely and universally involved. Splenium of th e corpus callosum was frequently but not always involved. We conclude there is a form of associative visual agnosia with agnosia for objects and printed words but sparing face recognition which has a characteri stic unilateral neuropathology. Damage or disconnection of dominant pa rahippocampal, fusiform and lingual gyri is the necessary and sufficie nt lesion.