Abstract
Two patients with abnormal writing behavior are reported, and the neuropsychological mechanisms for their writing deficits are discussed. Case 1 is a right-handed Wernicke's aphasic, who showed prominent jargonagraphia written in kanji and kana. Kinethetic images of characters stored in the left hemisphere are considered to run on freely without control from the language area in the right hemisphere, causing jargonagraphia. In addition, this patient tried to use writing to compensate for his speech disturbances, and he kept a diary and showed it to care staff. These abnormal behaviors seem to be related to anosognosia for writing deficits. His productive writing seems to partly resemble hypergraphia, observed in right-brain-damaged patients. Case 2 showed increased writing with prominent perseveration with abnormal grasping phenomenon due to diffuse subcortical lesions in the bilateral frontal lobes. His hypergraphic activity was triggered by the appearance of the writing tools. This abnormal writing behavior is interpreted as utilization behavior relatively limited to writing tools. Deficits of inhibitory mechanisms from the frontal to the parietal lobe might have released writing activities in this patient.
