Wu T, Sommer M, Tergau F, Paulus W
Department of Clinical Neurophysiology, Georg August University, Robert-Koch-Strasse 40, D-37077, Göttingen, Germany.
Neurosci Lett. 2000 Jun 16;287(1):37-40. doi: 10.1016/s0304-3940(00)01132-0.
We studied the effects of a train of 30 pulses of repetitive transcranial magnetic stimulation (rTMS) at frequencies of 5 and 15 Hz and at an intensity of 120% of resting motor threshold on human motor cortex excitability. Intracortical inhibition (ICI) and intracortical facilitation (ICF) after rTMS were tested by a conditioning-test designed paired-pulse paradigm. After 15 Hz rTMS, ICI was significantly reduced for 3.2 min, ICF was enhanced for 1.5 min, muscle evoked potentials from single TMS were increased in the first 30 s only. After 5 Hz rTMS ICI was significantly reduced in the first 32 s. We conclude that high-frequency suprathreshold rTMS transiently suppresses the activity of the intracortical inhibitory circuitry and, with a different time course, increases the excitability of the excitatory circuitry.
我们研究了一系列30个脉冲的重复经颅磁刺激（rTMS），频率分别为5赫兹和15赫兹，强度为静息运动阈值的120%，对人类运动皮层兴奋性的影响。rTMS后的皮质内抑制（ICI）和皮质内易化（ICF）通过条件测试设计的配对脉冲范式进行检测。在15赫兹rTMS后，ICI显著降低3.2分钟，ICF增强1.5分钟，单次TMS诱发的肌肉动作电位仅在最初30秒内增加。在5赫兹rTMS后，ICI在最初32秒内显著降低。我们得出结论，高频阈上rTMS可短暂抑制皮质内抑制性回路的活动，并在不同的时间进程中增加兴奋性回路的兴奋性。
