磁刺激穴位镇痛诱发的脑电信号特征成分及源定位

Characteristic components and source localization of electroencephalogram signals evoked by magnetic stimulation at acupoints

背景:针灸是中国传统医学的重要组成部分。穴位治疗作用是否具有生理基础或者只是心理作用一直是争议的焦点。目前临床中常用的穴位刺激方式为手针和电针,很少有关于磁刺激穴位引起脑电活动的文献发表。目的:利用诱发电位来研究磁刺激合谷穴对大脑皮质功能区的影响,探讨磁刺激穴位镇痛机制。方法:18名被试(男13名,女5名)自愿参加实验,选取右侧合谷穴作为靶点目标,距离合谷穴约3cm处的非穴位点作为对照点。磁刺激频率为1Hz,刺激强度为1.76T,实验分别采集磁刺激前、中、后的脑电信号。结果与结论:磁刺激穴位140～170ms后,在F3,F1,FZ,F2,F4,FC3,FC1,FCZ,FC2,FC4等电极处记录到诱发电位晚成分P150。对该成分进行偶极子源定位分析发现P150定位于前扣带回后部,之前的研究已经证明前扣带回不仅参与痛觉认知,还参与痛觉的调制。结果揭示了磁刺激穴位可能的镇痛机制。

BACKGROUND：Acupuncture is an important part of traditional Chinese medicine.Whether acupuncture analgesia has a physiological basis or other psychological effects has long been a focus of argument.Manual manipulation and electrical acupuncture manipulations are clinically used.There are few published on the electroencephalogram （EEG） changes during magnetic stimulation at an acupuncture site.OBJECTIVE：EEG data in response to magnetic stimulation at Hegu （LI4） acupoint were measured to determine whether magnetic acupoint stimulation might modulate cortex function or not.The mechanism of analgesic effect induced by magnetic stimulation at acupoint was discussed.METHODS：Eighteen healthy volunteers （13 male,5 female） were chosen in this experiment,with consent obtained before the study.LI4 acupoint lying at right were selected.The distance between mock point and LI4 was 3 cm.The frequency of stimulation was 1 Hz,and the intensity was 1.76T.EEG data were recorded before,during and after stimulation.RESULTS AND CONCLUSION：Evoked potential was recorded in F3,F1,FZ,F2,F4,FC3,FC1,FCZ,FC2,FC4 electrodes,at about 140-170 ms （P150） after acupoint stimulation.With regard to the location of P150 in the human brain,it was located to the contralateral anterior cingulated cortex （ACC）.Previous research has shown that ACC was not only involved in cognition of pain,but also modulated by analgesics.The result suggests the potential mechanism of analgesic effect induced by magnetic stimulation at acupoint.