Abstract
In order to detect the functional subsets of the mesial frontal lobe, 26 patients with lesions involving mesial frontal lobe were investigated. The results were summarized as follows; (1) Hemiparesis predominantly in lower extremity was common motor deficit in patients with mesial frontal motor cortices. Four patients with supplementary motor damage sparing motor cortex showed long lasting hemiparesis. (2) Verbal adynamia was common symptom due to left supplementary motor and superior prefrontal damage. Transient mutism was found in two patients with superior prefrontal damage without the involvement of supplementary motor cortex. (3) Emotional disturbance char acterized by depressed motivation was also common. No hemispheric laterality could be detected in these patients. (4) Dementia and memory disturbance related to the pole and anterior area of superior prefrontal damage. (5) Transient urinary incontinence was presented only by right superior prefrontal damage, and permanent incontinence related with bilateral damage. (6) Akinetic mutism was related with bilateral large damage including cingulate. (7) Motor neglect and dressing apraxia possibly due to programing disturbance related to lesions in right hemisphere.