title: Contribution of the supplementary motor area and anterior cingulate gyrus to pathological grasping phenomena.
abstract: To investigate the relationship between the site of brain damage and characteristics of the pathological grasping phenomena, we examined different varieties of the reaction in a consecutive series of 28 patients with unilateral hemispheric damage due to stroke. Patients with a lesion relatively confined to the supplementary motor area (n = 4) constantly exhibited a grasp reflex, mainly in the hand contralateral to the lesion, but they never showed a groping reaction. By contrast, patients with damage primarily involving the anterior cingulate gyrus (n = 3) developed the groping reaction in the hand contralateral to the lesion, but they had only a very mild grasp reflex in that hand. Patients with damage involving both the supplementary motor area and the anterior cingulate gyrus (n = 12) showed the grasp reflex and groping reaction mainly in the hand contralateral to the lesion. Patients with damage to the medial parietal lobe (n = 2), those with damage to the lateral convexity of the hemisphere (n = 6), and a patient with damage confined to the corpus callosum did not exhibit such grasping phenomena. From these observations, we conclude that the grasp reflex is closely related to a lesion of the supplementary motor area, whereas the groping reaction is bound to a lesion of the anterior cingulate gyrus.
authors.affiliation: Department of Neurology, Jichi Medical School, Tochigi, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Hashimoto
authors.forename: Y
authors.initials: Y
authors.lastname: Tanaka
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001927:Brain Diseases / Q000473:pathology; D005260:Female; D006179:Gyrus Cinguli / Q000473:pathology*; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000473:pathology*; D011446:Prospective Studies; D012018:Reflex / Q000502:physiology*