基于运动诱发电位探讨针刺合谷穴对颊肌特异性作用的研究

关键词：经颅磁刺激  运动诱发电位  针刺  合谷穴  曲池穴  穴位特异性  电针

Keywords:transcranial magnetic stimulation  motor evoked potentials  acupuncture  Hegu（LI4）  Quchi（LI11）  point specificity  electroacupuncture

摘要：

      摘要 目的：以“面口合谷收”理论为落脚点，旨在用现代医学角度探索合谷穴对面神经产生影响的机制，探讨与他穴相比较合谷穴对面部作用的特异性，以期为针灸临床实践提供指导。 方法：纳入21例健康受试者，采用交叉设计（同体自身前后对照）。试验一将志愿者随机先后分至合谷组和曲池组（两组间隔两周作为洗脱期），比较针刺合谷、曲池前后，颊肌在经颅磁刺激（transcranial magnetic stimulation，TMS）各个强度下运动诱发电位（motor evoked potentials， MEPs）的潜伏期、波幅；试验一结束后，全部受试者间隔两周后进入试验二，试验二分组方法同试验一，并记录TMS在15%刺激强度下8个时间点（针刺前、针刺、留针3min、电针、电针后3min、关闭电针、关闭电针后3min后和拔针）的颊肌MEPs波幅和潜伏期。 结果：TMS强度1%—25%下合谷组、曲池组干预前后颊肌MEPs波幅均显著增高，潜伏期均显著降低，差距均有显著性意义（P<0.001），且合谷组波幅变化率明显高于曲池组波幅变化率（P<0.01）。试验二中，合谷组在针刺前颊肌MEPs波幅低于曲池组波幅（P<0.01），在电针、电针3min、关闭电针、关闭电针3min后，波幅高于曲池组（P<0.05）；曲池组在针刺前、针刺后、电针、电针3min、关闭电针的颊肌MEPs潜伏期低于合谷组（P<0.05），其他干预阶段两组无显著性差异（P>0.05）。 结论：生理状态下，针刺合谷和曲池均能提高颊肌兴奋性，且合谷穴相较于曲池穴对颊肌兴奋性提高更具有特异性。

Abstract:

      Abstract Objective： To explore the mechanism of Hegu（LI4） point's effect on facial nerve from the perspective of modern medicine. Additionally, it seeks to investigate the specificity of LI4 effect on the face in comparison with other points， providing guidance for the clinical practice of acupuncture. Method： Twenty healthy subjects were enrolled in a crossover design （homozygous self before and after control）. The volunteers were randomly assigned to the LI4 group and the Quchi（LI11） group, with a two-week interval between the two groups was used as the washout period. The motor evoked potentials （MEPs） of the facial buccal muscles were compared before and after acupuncture in the LI4 and LI11 groups under various intensities of transcranial magnetic stimulation （TMS）. The latency and amplitude of MEPs were measured at each intensity of TMS. At the end of the first trial， all volunteers entered the second trial after a two-week interval， with the grouping method of the second trial being the same as that of the first trial. The amplitude and latency of buccal muscle MEPs were recorded at eight time points（before needling， needling， leaving the needle in place for 3 minutes， electro-acupuncture，3 minutes after electro-acupuncture， switching off electro-acupuncture，3 minutes after switching off electro-acupuncture and pulling out the needle） at a stimulation intensity. Result： The amplitude of buccal muscle MEPs increased significantly and the latency decreased significantly before and after the intervention in the LI4 and LI11 groups under TMS intensity of 1% to 25%. The difference was statistically significant（P<0.001）， and the rate of change in the amplitude of buccal muscle MEPs in the LI4 and the rate of change in the amplitude of buccal muscle MEPs in the LI4 group was significantly higher than that in the LI11 group（P<0.01）. In test 2， the amplitude of buccal muscle MEPs in the LI4 group was lower than that in the LI11 group before acupuncture（P<0.01）. The amplitude of buccal muscle MEPs was higher than that in the LI11group after electro-acupuncture， electro-acupuncture for 3 minutes， switching off electro-acupuncture， and switching off electro-acupuncture for 3 minutes（P<0.05）. The latency of buccal muscle MEPs was lower than that of the LI4 group in the LI11group before， after， electro-acupuncture， electro-acupuncture， electro-acupuncture for 3 minutes， and switching off electro-acupuncture（P<0.05）. There was no statistically significant difference between the two groups in other intervention phases（P>0.05）. Conclusion： In the physiological state， needling both Hegu and Quchi increased buccal muscle excitability， and Hegu acupoints were more specific for increasing buccal muscle excitability compared with Quchi acupoints.