Wassermann E M, Wedegaertner F R, Ziemann U, George M S, Chen R
Medical Neurology Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD 20892-1428, USA.
Neurosci Lett. 1998 Jul 10;250(3):141-4. doi: 10.1016/s0304-3940(98)00437-6.
Electrophysiological studies have shown that 1-Hz repetitive transcranial magnetic stimulation (rTMS) of the primary motor area (M1) can produce a local decrease in excitability. Functional imaging data suggest that this change may be bilateral. In normal subjects, we measured motor evoked potential (MEP) amplitude at a series of stimulation intensities in the contralateral M1 before and after 15 min of active or sham rTMS at just above the MEP threshold. The slope of the curve relating MEP amplitude and stimulation intensity was decreased in the unstimulated hemisphere by active but not sham rTMS. This demonstrates that rTMS can condition cortical excitability at a distance of one or more synapses and suggest that decreased excitability to TMS is a correlate of decreased blood flow and metabolism.
电生理研究表明，对初级运动区（M1）进行1赫兹重复经颅磁刺激（rTMS）可导致局部兴奋性降低。功能成像数据表明，这种变化可能是双侧性的。在正常受试者中，我们在对侧M1区以略高于运动诱发电位（MEP）阈值的强度进行15分钟的主动或伪rTMS刺激前后，测量了一系列刺激强度下的MEP振幅。主动rTMS而非伪rTMS使未受刺激半球中MEP振幅与刺激强度关系曲线的斜率降低。这表明rTMS可在一个或多个突触距离处调节皮质兴奋性，并提示对TMS兴奋性的降低与血流和代谢的减少相关。
