Neuropsychological deficits associated with a tumour in the posterior corpus callosum: a report of two cases.

This study reports two patients with tumours arising from the splenium of the corpus callosum that caused a memory disturbance consistent with retrosplenial amnesia as well as a variety of cognitive deficits including agraphia, acalculia, constructional apraxia and ideomotor and ideational apraxia involving both hands, but not aphasia. Patients showed disorientation to time and place, impaired recent memory and memorizing capacity; immediate and remote memory were preserved. Despite impaired performance intelligence quotients (IQ), verbal IQ was relatively spared. Patients also showed disconnection symptoms including bilateral crossed visuomotor ataxia and alexia to stimuli presented in the right visual field. In both cases, the tumour of the splenium had provoked surrounding oedema extending to the left parietal and occipital lobes.