Right unilateral agraphia following callosal infarction in a left-hander.

A left-handed Japanese man is reported who presented right-hand agraphia and tactile anomia following callosal infarction. Magnetic resonance imaging revealed an ischemic lesion extending from the posterior half of the trunk to the splenium of the corpus callosum. In his right handwriting, the 'Kana' (phonogram) was more severely impaired than the 'Kanji' (ideogram), and the most frequent typewriting error was morphological followed by neographism. His visuoconstructional ability was also more impaired in the right hand than in the left. Right-hand agraphia in our case is readily explained by the right hemisphere dominance both for language and visuoconstructional ability.