反复疼痛的临床情况通常涉及伤害性和非伤害性输入。这些刺激之间的关联很可能随着时间的推移而被学习。这种学习可能是随后疼痛放大的基础,或在没有伤害性感受的情况下引起疼痛。
我们进行了系统综述和荟萃分析,以评估异常性疼痛或痛觉过敏可能是经典条件反应的证据。对文献的敏感搜索涵盖了Medline,Embase,CINAHL,AMED,PubMed,Scopus,Psycarticles,PsycINFO,科克伦图书馆,和WebofScience。通过联系专家和搜索已发表的评论来确定其他研究。两名审稿人独立评估纳入研究,评估的偏见风险,并提取数据。包括研究,如果他们的目的是引发或放大疼痛使用经典的调理程序在健康,成年人。如果研究不区分古典条件和明确的口头暗示作为学习来源,则被排除在外。或者没有使用体验式学习。
13项研究,有不同的偏见风险,包括在内。十项研究评估了经典的条件性痛觉过敏:九项发现了痛觉过敏;一个没有。汇总效应(n=8,完整数据)显示预处理后疼痛显着增加(0-100疼痛量表的平均差为7.40[95CI:4.00-10.80])。三项研究评估了条件异常性疼痛,发现结果相互矛盾。
现有文献表明,经典的调理可以放大疼痛。关于经典调理是否会引起疼痛,尚无结论。需要对伤害性非条件刺激进行严格的实验条件研究,以填补这一知识空白。
Clinical scenarios of repeated pain usually involve both nociceptive and non-nociceptive input. It is likely that associations between these stimuli are learned over time. Such learning may underlie subsequent amplification of pain, or evocation of pain in the absence of nociception.
We undertook a systematic
review and meta-analysis to evaluate the evidence that allodynia or hyperalgesia can be a classically conditioned response. A sensitive search of the literature covered Medline, Embase, CINAHL, AMED, PubMed, Scopus, PsycArticles, PsycINFO, Cochrane Library, and Web of Science. Additional studies were identified by contacting experts and searching published reviews. Two reviewers independently assessed studies for inclusion, evaluated risk of bias, and extracted data. Studies were included if they aimed to elicit or amplify pain using a classical conditioning procedure in healthy, adult humans. Studies were excluded if they did not distinguish between classical conditioning and explicit verbal suggestion as learning sources, or did not use experiential learning.
Thirteen studies, with varying risk of bias, were included. Ten studies evaluated classically conditioned hyperalgesia: nine found hyperalgesia; one did not. Pooled effects (n = 8 with full data) showed a significant pain increase after conditioning (mean difference of 7.40 [95%CI: 4.00-10.80] on a 0-100 pain scale). Three studies evaluated conditioned allodynia and found conflicting results.
The existing literature suggests that classical conditioning can amplify pain. No conclusions can be drawn about whether or not classical conditioning can elicit pain. Rigorous experimental conditioning studies with nociceptive unconditioned stimuli are needed to fill this gap in knowledge.