Isolated lexical agraphia in a right-handed patient with a posterior lesion of the right cerebral hemisphere.

Lexical agraphia is thought to result from impairment of the lexical spelling system and is characterized by better spelling of nonwords and regularly spelled words than irregularly spelled words. Previous reports have suggested a localization of this syndrome in the region of the left posterior-superior angular gyrus and parietal-occipital lobule, sparing the supramarginal gyrus. We describe a right-handed man who after open-heart surgery displayed lexical agraphia without aphasia, alexia, apraxia, or Gerstmann's syndrome. Computed tomography disclosed a lesion not on the left but on the right in the posterior parietal-occipital region.