Modality specific naming and gesture disturbances: a case with optic aphasia, bilateral tactile aphasia, optic apraxia and tactile apraxia.

This study reports a patient who manifested optic aphasia, tactile aphasia, optic apraxia, and tactile apraxia following an operation for epidural left parietal haematoma. He could neither name nor pantomime the use of objects presented visually or tactually, but correctly performed semantic association tasks, thus demonstrating preserved recognition. He could name and pantomime the use of auditorily presented objects. Experimental results disproved that pantomime disorders were secondary to naming disorders, and suggested that modality specific aphasia and modality specific apraxia are independent clinical syndromes. CT scans showed injury to the posterior callosal radiations, the white matter of the angular gyrus, and the medial portion of the occipital lobe in the left hemisphere. We suggest that modality specific aphasia and modality specific apraxia can be explained by assuming a common semantic memory store.