Gorsler A, Bäumer T, Weiller C, Münchau A, Liepert J
Department of Neurology, University Hospital Hamburg-Eppendorf, Hamburg, Germany.
Clin Neurophysiol. 2003 Oct;114(10):1800-7. doi: 10.1016/s1388-2457(03)00157-3.
We investigated whether repetitive transcranial magnetic stimulation (rTMS) applied to the right motor cortex modified the excitability of the unstimulated left motor cortex.
Interhemispheric effects of 0.5 and 5 Hz subthreshold rTMS over the right motor cortex were examined by single pulse and paired pulse TMS and by transcranial electrical stimulation (TES) applied to the unstimulated left motor cortex. The effects of (a) 1800 pulses real and sham rTMS with 5 Hz, (b) 180 pulses real and sham rTMS with 0.5 Hz and (c) 1800 pulses real rTMS with 0.5 Hz were studied.
Following 5 Hz right motor rTMS motor evoked potential (MEP) amplitudes induced by single pulse TMS over the left motor cortex increased significantly. Intracortical inhibition (ICI) and facilitation (ICF) and MEP amplitudes evoked by TES were unchanged. Sham stimulation had no influence on motor cortex excitability. After 180 pulses right motor cortex rTMS with 0.5 Hz a significant decrease of left motor ICF, but no change in single pulse MEP amplitudes was found. A similar trend was observed with 1800 pulses rTMS with 0.5 Hz.
High frequency right motor rTMS can increase left motor cortex excitability whereas low frequency right motor rTMS can decrease it. These effects outlast the rTMS by several minutes. The underlying mechanisms mediating interhemispheric excitability changes are likely to be frequency dependent.
我们研究了应用于右侧运动皮层的重复经颅磁刺激（rTMS）是否会改变未受刺激的左侧运动皮层的兴奋性。
通过单脉冲和配对脉冲经颅磁刺激（TMS）以及应用于未受刺激的左侧运动皮层的经颅电刺激（TES），检测0.5赫兹和5赫兹阈下rTMS对右侧运动皮层的半球间效应。研究了（a）1800次5赫兹真刺激和假刺激rTMS、（b）180次0.5赫兹真刺激和假刺激rTMS以及（c）1800次0.5赫兹真刺激rTMS的效果。
右侧运动皮层进行5赫兹rTMS后，左侧运动皮层上由单脉冲TMS诱发的运动诱发电位（MEP）幅度显著增加。皮层内抑制（ICI）和易化（ICF）以及TES诱发的MEP幅度未发生变化。假刺激对运动皮层兴奋性没有影响。右侧运动皮层进行180次0.5赫兹rTMS后，左侧运动皮层的ICF显著降低，但单脉冲MEP幅度没有变化。0.5赫兹1800次rTMS也观察到类似趋势。
高频右侧运动rTMS可增加左侧运动皮层兴奋性，而低频右侧运动rTMS可降低其兴奋性。这些效应在rTMS结束后会持续几分钟。介导半球间兴奋性变化的潜在机制可能与频率有关。
