Morita H, Shindo M, Yanagawa S, Yanagisawa N
Department of Medicine (Neurology), Shinshu University School of Medicine, Matsumoto, Japan.
Muscle Nerve. 1993 Jun;16(6):648-54. doi: 10.1002/mus.880160611.
Paired stimulation has been used extensively in clinical neurophysiology. We studied change in the sizes of compound muscle action potentials (CMAPs) and compound nerve action potentials (CNAPs) in humans after a single electrical stimulus to the peripheral nerve. For the paired stimuli, potentials elicited by the first stimuli were used as the test responses. When the interstimulus intervals were varied, the second potentials underwent refractoriness and then were facilitated up to 20-30 ms, thereafter being depressed for 160-200 ms. When intensities were graded at fixed intervals for motor fibers the maximal effect was obtained with liminal stimulation, but was no longer observed at supramaximal stimulation. When the intensity used to obtain M-responses was half the maximum, maximal facilitations were 35% (CNAP) and 17% (CMAP) of the first potential, the respective maximal depressions being 13% and 42%. When the sizes of the two CNAPs were equalized by adjusting the second stimuli, the CMAP was facilitated (26%) up to 65 ms, thereafter being depressed (13%). These results must be taken into account when making clinical examinations that use paired stimulation.
配对刺激已在临床神经生理学中广泛应用。我们研究了对周围神经进行单次电刺激后人类复合肌肉动作电位（CMAP）和复合神经动作电位（CNAP）大小的变化。对于配对刺激，将第一个刺激引发的电位用作测试反应。当改变刺激间隔时，第二个电位会经历不应期，然后在20 - 30毫秒内得到易化，此后在160 - 200毫秒内受到抑制。当以固定间隔对运动纤维进行强度分级时，阈下刺激可获得最大效应，但在超强刺激时不再观察到这种效应。当用于获得M反应的强度为最大值的一半时，最大易化分别为第一个电位的35%（CNAP）和17%（CMAP），各自的最大抑制分别为13%和42%。通过调整第二个刺激使两个CNAP大小相等时，CMAP在65毫秒内得到易化（26%），此后受到抑制（13%）。在进行使用配对刺激的临床检查时，必须考虑这些结果。
