Alexia without agraphia in a left-handed patient with prosopagnosia.

A left-handed patient was studied who had the acute onset of alexia without agraphia, a left homonymous hemianopia, and prosopagnosia. Neurodiagnostic tests including computerized axial tomography and angiography disclosed bilateral lesions in the posterior cerebral hemispheres involving the splenium of the corpus callosum. Neuropsychologic examination indicated marked impairment of facial discrimination, deficient naming and memory of presented visual material, and mild visual agnosia with relative preservation of other cognitive functions. These findings are consistent with a double disconnection syndrome involving disconnection of the dominant angular gyrus and right inferotemporal cortex from their bilateral visual inputs.