Characterization of postexercise facilitation and depression of motor evoked potentials to transcranial magnetic stimulation
Characterization of postexercise facilitation and depression of motor evoked potentials to transcranial magnetic stimulation
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DOI：
10.1212/wnl.46.5.1376
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发表时间：
1996-05-01
期刊：
影响因子：
9.9
通讯作者：
Hallett, M
中科院分区：
文献类型：
--
作者：
Samii, A;Wassermann, EM;Hallett, M
我们研究了运动对经颅磁刺激(TMS)和经颅电刺激(TES)运动诱发电位(MEP)的影响。受试者进行30秒的桡侧腕伸肌等长运动，直到疲劳，疲劳被定义为不能保持一半的最大力量。在每个运动周期后，从静息肌肉记录的MEP到TMS的幅度平均是运动前的两倍以上(运动后MEP促进)。疲劳发生后，MEP波幅约为运动前的60%(运动后MEP抑制)。在休息几分钟后，抑郁的MEP逐渐恢复到运动前的水平。当运动强度为最大自主收缩的10%至50%时，运动后MEP促进作用保持不变，运动结束后几分钟内MEP促进作用衰减至基线。运动后MEP对TES无易化作用。我们假设运动后MEP易化和MEP抑制都是由皮质内机制引起的。
We studied the effects of exercise on motor evoked potentials (MEPs) to transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (TES). Subjects performed 30-second periods of isometric exercise of the extensor carpi radialis until fatigue, which was defined as the inability to maintain half maximum force. The amplitude of MEPs to TMS recorded from the resting muscle after each exercise period was on average more than twice the pre-exercise value (postexercise MEP facilitation). After fatigue occurred, the MEP amplitudes were approximately 60% of the pre-exercise value (postexercise MEP depression). There was a gradual recovery of the depressed MEPs to pre-exercise values over several minutes of rest. Postexercise MEP facilitation was constant when exercise intensity ranged from 10 to 50% of maximum voluntary contraction and it decayed to baseline over several minutes after the end of exercise. There was no postexercise MEP facilitation to TES. We hypothesize that both postexercise MEP facilitation and MEP depression are due to intracortical mechanisms.