Modulation of pain signal processing by electric acupoint stimulation: an electroencephalogram study

目的:利用64通道脑电图记录与分析系统探讨经皮穴位电刺激对镇痛相关的脑电活动的调制作用.方法:共15名健康青年被试参加了本研究.每名被试进行两轮实验,分别接受穴位电刺激和对照刺激(非穴位刺激).在治疗前后分别接受中等程度的疼痛刺激,并对每次疼痛刺激的强度进行评分.记录治疗前、中、后的脑电信号并进行频谱分析.结果:穴位电刺激时刺激对侧的中央及顶叶皮层θ波与治疗后的疼痛评分有负相关性,即疼痛评分越低或镇痛效果越好,则该脑区的θ波成分越多;类似的,穴位刺激时对侧前额叶、同侧额叶下部、颞叶和顶枕叶的β波也与治疗后的疼痛评分有负相关性.相反,在对照刺激时的脑电图没有发现类似的相关性.结论:脑电图频谱分析揭示穴位电刺激对某些特定脑区的疼痛信号处理过程具有一定的调制作用,这可能是针刺镇痛的机制之一.SUMMARY Objective: To investigate the analgesia-related modulation of electroencephalographic activities by transcutaneous electric acupoint stimulation (EAS). Methods: In 15 healthy human beings, 64-channel electroencephalogram was recorded and power spectrum analysis was employed before, during and after EAS. Non-acupoint electric stimulation was used as control. All subjects were asked to rate their sensation to painful stimulations before and after treatment. Results: The relative theta power near contra-lateral centro-parietal area during EAS was negatively correlated with the pain score after EAS. Similarly, the beta activity during EAS near contra-lateral prefrontal cortex, ipsi-lateral inferior frontal and temporal lobe, and ipsi-lateral occipito-parietal cortex, were all negatively correlated with pain score after EAS. Conclusion: These changes might reflect a modulation of brain activity by EAS in specific areas, which were in turn involved in modulation of certain aspects of pain-signal processing.国家自然科学基金; 面向21世纪教育振兴行动计划(985计划)中国科学引文数据库(CSCD)03236-2403