Facilitation of muscle evoked responses after repetitive cortical stimulation in man
Facilitation of muscle evoked responses after repetitive cortical stimulation in man
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DOI：
10.1007/s002210050493
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发表时间：
1998-09-01
影响因子：
2
通讯作者：
Manfredi, M
中科院分区：
文献类型：
--
作者：
Berardelli, A;Inghilleri, M;Manfredi, M
重复经颅磁刺激（rTMS）技术允许皮层运动区域被不同频率和强度的磁刺激序列激活。在本文中，我们研究了 rTMS 以 5 Hz 频率、运动阈值 120% 的强度传递到运动皮层的长期神经生理学效应。火车的每次刺激都会在手和前臂肌肉中产生肌肉诱发电位（MEP），从第一次冲击到最后一次冲击，这些电位的大小逐渐增加。列车结束后，对单次测试刺激的反应在 600-900 毫秒内保持增强。相比之下，训练对经颅电刺激引起的 MEP 大小没有影响，但它抑制前臂肌肉的 ii 反射达 900 毫秒。我们得出的结论是，这些参数的 rTMS 增加了运动皮层的兴奋性，并且这种效果比火车持续了近 1 秒。在脊髓水平，rTMS 可能会增加负责 H 反射的 Ia 传入纤维的突触前抑制。
The technique of repetitive transcranial magnetic stimulation (rTMS) allows cortical motor areas to be activated by trains of magnetic stimuli at different frequencies and intensities. In this paper, we studied longterm neurophysiological effects of rTMS delivered to the motor cortex at 5 Hz with an intensity of 120% of motor threshold. Each stimulus of the train produced muscle-evoked potentials (MEPs) in hand and forearm muscles, which gradually increased in size from the first to the last shock. After the end of the train, the response to a single-test stimulus remained enhanced for 600-900 ms. In contrast, the train had no effect on the size of the MEPs evoked by transcranial electrical stimulation, while it suppressed ii-reflexes in forearm muscles for 900 ms. We conclude that rTMS of these parameters increases the excitability of the motor cortex and that this effect outlasts the train for almost 1 s. At the spinal level, rTMS may increase presynaptic inhibition of Ia afferent fibers responsible for the H-reflex.