Lesion localization in apractic agraphia.

Apractic agraphia is an impairment in writing in which the actual orthographic production of letters and words is abnormal despite normal sensorimotor function, visual feedback, and word and letter knowledge. We report one case and review the limited clinicoanatomical literature. Analysis of available cases supports the hypothesis that apractic agraphia is one of several related clinical disorders that are due to the loss of spatially and kinesthetically modulated movements. It is produced by lesions in the superior parietal lobule, usually in the hemisphere dominant for language.