右半球病変により純粋失書と道順障害を呈した１例

Abstract

A 69-year-old, right-handed, Japanese male patient presented with pure agraphia with topographical disorientation after hemorrhage in the right parietal lobe. Upon developing cerebral hemorrhage, he was referred to our hospital for close examination of agraphia. There was no paresis or clumsiness in his extremities. His speech was fluent and well-articulated. Neither aphasia nor reading impairments was found, although there was a clear writing impairment with effort and hesitation. His writing of both kanji and kana letters contained additional, absent or deformed strokes or parts. No hemianopia, prosopagnosia, constructional disturbances and dressing apraxia were found. He could recognize familiar buildings or landscapes, but often lost his way around well-known areas. MR images revealed subcortical lesions of precuneus, superior and inferior parietal lobules in the right hemisphere, around the posterior horn of the lateral ventricle. He revealed pure agraphia and topographical disorientation after the right brain haemorrhage, without dementia or personality change. These findings indicate that the right parietal lobe participates in the kinesthetic movements of writing. Some authers have been documented cases of aphasic agraphia or alexia with agraphia caused by right hemisphere damage in dextrals, but pure agraphia caused by the lesion in the right hemisphere is very rare.