Motor Evoked Potential by Magnetic Stimulation

Research Project

Project/Area Number	63480330
Research Category	Grant-in-Aid for General Scientific Research (B)
Allocation Type	Single-year Grants
Research Field	Cerebral neurosurgery
Research Institution	Fukushima Medical University
Principal Investigator	KODAMA Namio Fukushima Medical School, Professor, 医学部, 教授 (40004999)
Co-Investigator(Kenkyū-buntansha)	SASAKI Tatsuya Fukushima medical school, Research associate, 医学部, 助手 (00153990)
Project Period (FY)	1990
Project Status	Completed (Fiscal Year 1990)
Budget Amount *help	¥4,200,000 (Direct Cost: ¥4,200,000) Fiscal Year 1990: ¥200,000 (Direct Cost: ¥200,000) Fiscal Year 1989: ¥800,000 (Direct Cost: ¥800,000) Fiscal Year 1988: ¥3,200,000 (Direct Cost: ¥3,200,000)
Keywords	Magnetic stimulation / Motor evoked potential
Research Abstract	Motor evoked potential (MEP) has been recorded by high voltage electrical stimulation. Magnetic stimulation, in contrast with electrical stimulation, is non invasive. But distribution of magnetic force generated by the coil has not been studied accurately. And then in dogs, MEP by transcranial magnetic stimulation is recorded from brachial muscle and epidural space at cervical level. Next, as clinical study, amplitude and latency of MEP recorded from the bilateral thiner muscle are investigated in the patients with hemiparesis. The following results are obtained. 1 : Magnetic induction flux density is greater at the edge of the coil than center. 2 : In anesthesied dogs, MEP is recorded from the brachial muscle, which latency is about 6-8msec. And MEP recorded from epidural space consist of two negative peaks corresponding to the electrical stimulation. 3 : In the patients with hemiplegia, MEP is not recorded. In the patients with hemiparesis, MEP has a tendency to be low amplitude and prolongation of latency, but it is not possible to evaluate motor function precisely. Transcranial magnetic stimulation is non invasive. MEP by magnetic stimulation will be useful for investigation of motor function.