Abstract
The pathology of pure agraphia is defined as writing ability impaired selectively by acquired brain damage without language deficit such as aphasia. Past studies have thus tried to identify the center of writing ability through investigation of brain lesions. Previous studies suggested that the locations of lesions inducing writing deficits include the left middle frontal gyrus, left superior parietal lobe, inferior part of the left temporal lobe, and the area from the left angular gyrus to the left temporal lobe. Few, cases of pure agraphia due to right hemisphere damage have been reported, however, and its pathology is not yet well understood. In this paper, we report a case of agraphia after right hemisphere infarction. The lesion included the right precentral gyrus and the area from the frontal lobe to the parietal lobe. The case is a right-handed 73-year-old male, a technical high school graduate. He demonstrated more severe agraphia with kana characters than kanji characters, but without aphasia, coma, dementia, agnosia, apraxia, or constructive disturbance. In this case, the focus of writing deficit of kana characters is thought to exist in the right hemisphere because of its anomalous lateralization. Possible lesions causing this symptom might be located in the right inferior frontal gyrus, operculum, trigone, cortex/subcortex of the right middle frontal gyrus, or the cortex/subcortex of the right supramarginal gyrus.
