Department of Rehabilitation Sciences, Faculty of Medicine and Health Sciences, SPINE Research Unit Ghent, Ghent University.
Pain in Motion International Research Group, Ghent.
Clin J Pain. 2019 Sep;35(9):794-807. doi: 10.1097/AJP.0000000000000724.
The nociceptive flexion reflex (NFR) is a spinal reflex induced by painful stimuli resulting in a withdrawal response. Research has shown that the NFR is inhibited through endogenous pain inhibitory mechanisms, which can be assessed by conditioned pain modulation (CPM) paradigms. Although accumulating research suggests that the NFR can be affected by CPM, no clear overview of the current evidence exists. Therefore, the present review aimed at providing such a synthesis of the literature. In addition, the influence of personal factors on the CPM of the NFR was investigated.
A systematic review was performed and reported following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Five electronic databases were searched to identify relevant articles. Retrieved articles were screened on eligibility using predefined inclusion criteria. Risk of bias was investigated according to the modified Newcastle-Ottawa Scale. Levels of evidence and strength of conclusion were assigned following the guidelines of the Dutch Institute for Healthcare Improvement.
Forty articles were included. There is some evidence that CPM produced by thermal or mechanical stimuli induces inhibitory effects on the NFR. However, inconclusive evidence exists with regard to the effect of electrical conditioning stimuli. While several personal factors do not affect CPM of the NFR, increased cognitive interference is associated with reduced NFR inhibition.
The present review demonstrates that certain types of nociceptive conditioning stimuli have the potential to depress, at the spinal level, nociceptive stimuli elicited from distant body regions. Although CPM of the NFR seems to be robust to the influence of several personal factors, it can be affected by cognitive influences.
伤害性屈肌反射（NFR）是一种由疼痛刺激引起的脊髓反射，导致退缩反应。研究表明，NFR 通过内源性疼痛抑制机制被抑制，这可以通过条件性疼痛调制（CPM）范式来评估。尽管越来越多的研究表明 NFR 可以受到 CPM 的影响，但目前还没有关于该主题的综合概述。因此，本综述旨在提供文献的综合概述。此外，还研究了个人因素对 NFR 的 CPM 的影响。
按照系统评价和荟萃分析的首选报告项目（PRISMA）指南进行系统评价并报告。在五个电子数据库中进行了检索，以确定相关文章。使用预定的纳入标准对检索到的文章进行了筛选。根据改良的纽卡斯尔-渥太华量表评估偏倚风险。根据荷兰医疗保健改进研究所的指南，确定证据水平和结论强度。
共纳入 40 篇文章。有一些证据表明，热或机械刺激产生的 CPM 会对 NFR 产生抑制作用。然而，关于电条件刺激的效果存在不确定的证据。虽然一些个人因素不会影响 NFR 的 CPM，但认知干扰增加与 NFR 抑制减少有关。
本综述表明，某些类型的伤害性条件刺激有可能在脊髓水平上抑制来自身体远处区域的伤害性刺激。尽管 NFR 的 CPM 似乎不受几个个人因素的影响，但它可能会受到认知影响的影响。
