Health Innovations Research Institute, School of Health Sciences, RMIT University, Bundoora, Vic 3083, Australia.
Eur J Pain. 2010 Aug;14(7):725-31. doi: 10.1016/j.ejpain.2009.11.006. Epub 2009 Dec 31.
Temporal summation of pain, a phenomenon of the central nervous system (CNS), represents enhanced painful sensation or reduced pain threshold upon repeated stimulation. This pain model has been used to evaluate the analgesic effect of various medications on the CNS.
The present study aimed to evaluate the effects and characteristics of analgesia induced by electroacupuncture (EA), manual acupuncture (MA) and non-invasive sham-acupuncture (SA) in healthy humans on temporal summation of pain.
Thirsty-six pain-free volunteers were randomised into one of the three groups EA (2/100 Hz), MA or SA. Acupuncture intervention was on ST36 and ST40 on the dominant leg delivered by an acupuncturist blinded to the outcome assessment. Both subjects and the evaluator were blinded to the treatment allocation. Pain thresholds to a single pulse (single pain threshold, SPT) and repeated pulses electrical stimulation (temporal summation thresholds, TST) were measured before, 30 min after and 24h after each treatment.
The baseline values of three groups were comparable. Compared to SA, EA significantly increased both SPT and TST immediately after the treatment on the treatment leg as well as 24h after on both the treatment and non-treatment legs (ANOVA, p<0.05). MA also increased SPT and TST, but the changes were not significantly different from those induced by SA.
EA induces bilateral, segmentally distributed and prolong analgesia on both SPT and TST, indicating a non-centrally specific effect. This effect needs to be verified with heat or mechanical model and in pain patients.
疼痛的时间总和，是一种中枢神经系统（CNS）现象，表现为重复刺激时疼痛感觉增强或疼痛阈值降低。这种疼痛模型已被用于评估各种药物对中枢神经系统的镇痛效果。
本研究旨在评估电针（EA）、手动针刺（MA）和非侵入性假针刺（SA）在健康人群中对疼痛时间总和的镇痛作用及其特点。
将 36 名无痛志愿者随机分为 EA（2/100Hz）、MA 或 SA 三组。针刺干预由一名针刺师在优势腿的 ST36 和 ST40 进行，针刺师对结果评估不知情。受试者和评估者均对治疗分配不知情。在单次脉冲（单次疼痛阈值，SPT）和重复脉冲电刺激（时间总和阈值，TST）之前、治疗后 30 分钟和 24 小时测量疼痛阈值。
三组的基线值相当。与 SA 相比，EA 在治疗腿上治疗后即刻以及 24 小时后对治疗和非治疗腿上的 SPT 和 TST 均显著增加（ANOVA，p<0.05）。MA 也增加了 SPT 和 TST，但与 SA 诱导的变化没有显著差异。
EA 诱导双侧、节段性分布和延长 SPT 和 TST 的镇痛作用，表明其具有非中枢特异性效应。这种效应需要通过热或机械模型以及在疼痛患者中进行验证。
