Chiappa K H, Cros D, Day B, Fang J J, Macdonell R, Mavroudakis N
Department of Neurology, Massachusetts General Hospital, Boston 02114.
Electroencephalogr Clin Neurophysiol Suppl. 1991;43:186-201.
Voluntary contraction of a muscle greatly increases the amplitude and decreases the latency of the motor potentials evoked by electromagnetic coil brain stimulation (facilitation). Facilitation has also been observed with contraction of a nearby ipsilateral and a contralateral homologous muscle. We studied these facilitatory relationships in 5 normal subjects in small hand, forearm and upper arm muscles using surface-recorded compound motor action potentials, single motor unit recordings, and post-stimulus time histograms. There was no evidence for spread of facilitation between any pair of muscles if the muscle from which motor evoked potentials (MEPs) were recorded was completely at rest during brain stimulation, although this sometimes required training to accomplish or could not be achieved. Thus, although spread of facilitation has been observed by others under these conditions, we did not find this effect. There may be significant interindividual variations in the degree of facilitatory spread.
肌肉的自主收缩会显著增加由电磁线圈脑刺激诱发的运动电位的幅度，并缩短其潜伏期（易化作用）。在同侧附近肌肉和对侧同源肌肉收缩时也观察到了易化作用。我们使用表面记录的复合运动动作电位、单运动单位记录和刺激后时间直方图，对5名正常受试者的手部、前臂和上臂小肌肉中的这些易化关系进行了研究。如果在脑刺激期间记录运动诱发电位（MEP）的肌肉完全处于静止状态，则没有证据表明易化作用会在任何一对肌肉之间扩散，尽管这有时需要训练才能实现，或者根本无法实现。因此，尽管其他人在这些条件下观察到了易化作用的扩散，但我们并未发现这种效应。易化作用扩散的程度可能存在显著的个体差异。
