Mechanism of the silent period following transcranial magnetic stimulation - Evidence from epidural recordings
Mechanism of the silent period following transcranial magnetic stimulation - Evidence from epidural recordings
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DOI：
10.1007/s002210050878
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发表时间：
1999-10-01
影响因子：
2
通讯作者：
Ashby, P
中科院分区：
文献类型：
--
作者：
Chen, R;Lozano, AM;Ashby, P
我们通过记录植入颈部硬膜外电极的患者的皮质脊髓齐射来研究经颅磁刺激后沉默期（SP）的性质。单一的阈上测试刺激和成对的刺激间隔（ISI）为50-200毫秒，而受试者保持恒定的背景收缩。来自单个测试刺激的静默期持续时间为357+/-62 ms。在所有测试的ISI处，测试运动诱发电位均显著降低。在LSI为50 ms时，由测试刺激引起的I（间接）波基本上没有变化，这表明运动皮层兴奋性几乎没有变化。然而，皮质脊髓齐射，特别是晚I波，大大减少在ISI的100毫秒，150毫秒，和200毫秒。我们的研究结果表明，SP的早期部分主要是由于脊髓机制，而SP的后期部分与运动皮层兴奋性降低有关。
We investigated the nature of the silent period (SP) following transcranial magnetic stimulation by recording corticospinal volleys in a patient with implanted cervical epidural electrodes. Single suprathreshold test stimuli and paired stimuli at interstimulus intervals (ISIs) of 50-200 ms were delivered while the subject maintained a constant background contraction. The silent period duration from a single test stimulus was 357+/-62 ms. The test motor-evoked potentials were markedly reduced at all the ISIs tested. The I (indirect) waves induced by the test stimulus were largely unchanged at an LSI of 50 ms, suggesting that there was little change in motor cortex excitability. However, the corticospinal volleys, especially the late I waves, were substantially reduced at ISIs of 100 ms, 150 ms, and 200 ms. Our findings suggest that the early part of the SP is mainly due to spinal mechanisms, while the late part of the SP is related to reduced motor cortex excitability.