RELATION OF CEREBRAL CORTEX TO SPASTICITY AND FLACCIDITY

Abstract

Following cortical ablations, observations on spasticity and flaccidity have been made on monkeys and chimpanzees. Primary removal of various cortical areas has confirmed previous observations as follows a. Removal of areas 6 and 4s produced moderate spastic paresis. b. Removal of area 4 or of the anterior lip of the central sulcus caused paresis without spasticity. c. Removal of postcentral gyrus or of posterior lip of central sulcus caused transient flaccidity, and some paresis. Spasticity was usually increased in monkeys although this was not always marked. In chimpanzees, after a short initial period of marked flaccidity, definite spasticity appeared. d. Combined lesions of area 4 and postcentral gyrus produced greater spasticity than did lesions of postcentral gyrus alone. e. Addition of any contralateral motor area to a primary lesion causing spasticity increased this spasticity. f. Removal of an entire hemisphere secondary to ablation of areas 4 and 6 augmented spasticity and paresis to greater degree than did secondary ablation of postcentral gyrus. Histologic examination demonstrated that hemi-spherectomy was followed by complete degeneration within the pyramid whereas removal of areas 4 and 6 caused only partial degeneration therein.