Jacobs Mark F, Zapallow Christopher M, Tsang Philemon, Lee Kevin G H, Asmussen Michael J, Nelson Aimee J
Department of Kinesiology, University of Waterloo, Waterloo, Canada.
Neuroreport. 2012 Nov 14;23(16):927-31. doi: 10.1097/WNR.0b013e328358b0f3.
The present study examines the influence of primary somatosensory cortex (SI) on corticospinal excitability within primary motor cortex (M1) using repetitive transcranial magnetic stimulation. Two groups of subjects participated and both received continuous theta-burst stimulation (cTBS) over SI. One group received cTBS oriented to induce anterior-to-posterior (AP) followed by posterior-to-anterior (PA) current flow in the cortex and the other group received cTBS in the opposite direction (PA-AP). Motor evoked potentials (MEPs) were measured from the first dorsal interosseous muscle of the left and right hand before and at three time points (5, 25, 45 min) following cTBS over left-hemisphere SI. CTBS over SI in the AP-PA direction increased contralateral MEPs at 5 and 45 min with a near significant increase at 25 min. In contrast, PA-AP cTBS decreased contralateral MEPs at 25 min. We conclude that cTBS over SI modulates neural output directed to the hand with effects that depend on the direction of induced current.
本研究使用重复经颅磁刺激，探讨初级体感皮层（SI）对初级运动皮层（M1）内皮质脊髓兴奋性的影响。两组受试者参与了研究，且均接受了SI区域的连续theta爆发式刺激（cTBS）。一组接受的cTBS旨在诱发皮层从前向后（AP）然后从后向前（PA）的电流，另一组接受相反方向（PA - AP）的cTBS。在对左半球SI进行cTBS之前以及之后的三个时间点（5、25、45分钟），测量左右手第一背侧骨间肌的运动诱发电位（MEP）。AP - PA方向的SI区域cTBS在5分钟和45分钟时增加了对侧MEP，在25分钟时增加接近显著水平。相反，PA - AP方向的cTBS在25分钟时降低了对侧MEP。我们得出结论，SI区域的cTBS调节指向手部的神经输出，其效果取决于诱发电流的方向。
