Motor SystemsSomesthetic function of supplementary motor area during voluntary movementsMima, Tatsuya3; Ikeda, Akio1; Yazawa, Shogo3; Kunieda, Takeharu4; Nagamine, Takashi1; Taki, Waro5; Shibasaki, Hiroshi1,6Author Information 1Department of Brain Pathophysiology, Kyoto University Graduate School of Medicine, Shogoin, Sakyo-ku, Kyoto 606–8507 2Department of Neurosurgery, Kyoto University Graduate School of Medicine, Shogoin, Sakyo-ku, Kyoto 606–8507 3Department of Neurology, Miyazaki Prefectural Hospital of Nobeoka, Nobeoka, Miyazaki, 882–0835 4Department of Neurosurgery, Mie University School of Medicine, Edobashi 2–174, Tsu, Mie 514–0001, Japan 5Present address: Human Motor Control Section, Medical Neurology Branch, NINDS, National Institutes of Health, MSC 1430, Bethesda, MD 20892-1430, USA. 6Corresponding Author: Hiroshi Shibasaki ACKNOWLEDGEMENTS: This study was supported by Grants-in-Aid for Scientific Research (A) 09308031, (A) 08558083, on Priority Areas 08279106, and (C) 10670583 from Japan Ministry of Education, Science, Sports and Culture, Research for the Future Program from the Japan Society for the promotion of Science JSPS-RFTF97L00201. Received 30 March 1999; accepted 21 April 1999 NeuroReport: June 23rd, 1999 - Volume 10 - Issue 9 - p 1859-1862 Buy Abstract TO clarify the somesthetic functions of the supplementary motor area (SMA), we recorded the cortical potentials following the median nerve electric stimulation directly from the SMA and investigated the modulation caused by voluntary movements in two patients with intractable SMA seizures. The evoked potentials over the SMA consisted of positive (61.5 ms) and negative (100.0 ms) peaks, which were enlarged by voluntary movements of the stimulated hand. The present finding is in strong contrast with the attenuation (gating) of the response at the primary sensorimotor area (SM1) and suggests that the voluntary movements differently modulate the somatosensory functions of SMA and SM1. © 1999 Lippincott Williams & Wilkins, Inc.