ABERRANT MUSCLE ACTIVATION IN PATIENTS AFTER RESECTION OF NONPRIMARY MOTOR AREAS - DEMONSTRATION BY SURFACE ELECTROMYOGRAPHY

Two patients presented with a tumor involving mainly the supplementary motor area or the premotor cortex. Shortly after tumor resection, eac h developed transient impairment of voluntary movements. An electromyo gram, with the skin electrodes placed over the muscles of the upper ar ms and forearms, demonstrated aberrant ipsilateral, contralateral or b ilateral muscle activation during unilateral motor tasks in both patie nts. The bilateral activation was more prominent in the patient who ha d an intact dominant hemisphere. The present study suggests for the fi rst time the importance of non-primary motor areas of the human brain in activating the proper set of muscles on the proper side of the body . (C) 1998 Elsevier Science Ireland Ltd.