Silent period evoked by transcranial stimulation of the human cortex and cervicomedullary junction.
Silent period evoked by transcranial stimulation of the human cortex and cervicomedullary junction.
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经颅刺激人体皮质和颈髓交界处诱发的静默期。
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发表时间：
1993
期刊：
影响因子：
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通讯作者：
M. Manfredi
中科院分区：
文献类型：
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作者：
Maurizio Inghilleri;A. Berardelli;G. Cruccu;M. Manfredi
1.对10名健康受试者进行了经颅电刺激、经颅磁刺激、颈髓交界处电刺激和尺神经刺激后第一骨间背侧肌（FDI）诱发的沉默期研究。2.在最大强度电击的情况下，电TCS后的平均静默期持续时间为200 ms，磁TCS后为300 ms，颈髓交界处刺激后为43 ms，周围神经刺激后为100 ms。3.在磁TCS强度增加的情况下，比较了沉默期的持续时间、运动诱发电位的幅度和肌肉中产生的抽搐力。当刺激强度从刺激器输出的30%增加到70%时，沉默期的持续时间随着运动电位的幅度和肌肉抽搐的力的增加而延长。在70%至100%的输出时，运动电位的幅度和肌肉抽搐的力量饱和，而沉默期的持续时间继续增加。4.直接电刺激二头肌和腕伸肌引起的近端手臂肌肉抽搐不会抑制收缩的外国直接投资肌肉的自主活动。5.背景激活水平对磁TCS后FDI肌肉中记录的沉默期的持续时间没有影响。6. TCS后皮质运动神经元兴奋性研究通过一个单一的磁条件冲击和测试刺激组成的一个单一的磁冲击或单，双电击（刺激间隔1.8毫秒）在放松的肌肉。条件性磁冲击完全抑制了第二次磁冲击引起的反应，减少了单次电击引起的反应的大小，但不影响双次电击引起的反应。在肌肉收缩过程中也存在对测试磁冲击的抑制。7.我们的研究结果表明，TCS后前50 ms的沉默期主要是由脊髓机制产生的，如后超极化和脊髓运动神经元的反复抑制。如果下行抑制纤维有贡献，它们的贡献很小。本体感受输入的变化可能有轻微的影响。从50毫秒起，沉默期主要由皮层抑制机制产生。
1. The silent period evoked in the first dorsal interosseous (FDI) muscle after electrical and magnetic transcranial stimulation (TCS), electrical stimulation of the cervicomedullary junction and ulnar nerve stimulation was studied in ten healthy subjects. 2. With maximum‐intensity shocks, the average duration of the silent period was 200 ms after electrical TCS, 300 ms after magnetic TCS, 43 ms after stimulation at the cervicomedullary junction and 100 ms after peripheral nerve stimulation. 3. The duration of the silent period, the amplitude of the motor‐evoked potential, and the twitch force produced in the muscle were compared at increasing intensities of magnetic TCS. When the stimulus strength was increased from 30 to 70% of the stimulator output, the duration of the silent period lengthened as the amplitude of the motor potential and force of the muscle twitch increased. At 70 to 100% of the output, the amplitude of the motor potential and force of the muscle twitch saturated, whereas the duration of the silent period continued to increase. 4. Proximal arm muscle twitches induced by direct electrical stimulation of the biceps and extensor wrist muscles produced no inhibition of voluntary activity in the contracting FDI muscle. 5. The level of background activation had no effect on the duration of the silent period recorded in the FDI muscle after magnetic TCS. 6. Corticomotoneurone excitability after TCS was studied by means of a single magnetic conditioning shock and a test stimulus consisting either of one single magnetic shock or single and double electrical shocks (interstimulus interval 1.8 ms) in the relaxed muscle. A conditioning magnetic shock completely suppressed the response evoked by a second magnetic shock, reduced the size of the response evoked by a single electrical shock but did not affect the response evoked by double electrical shocks. Inhibition of the test magnetic shock was also present during muscle contraction. 7. Our findings indicate that the first 50 ms of the silent period after TCS are produced mainly by spinal mechanisms such as after‐hyperpolarization and recurrent inhibition of the spinal motoneurones. If descending inhibitory fibres contribute, their contribution is small. Changes in proprioceptive input probably have a minor influence. From 50 ms onwards the silent period is produced mainly by cortical inhibitory mechanisms.