Amiri Mohammadreza, Rhudy Jamie, Masani Kei, Kumbhare Dinesh
KITE Research Institute, University Health Network, Toronto, ON, M5G 2A2, Canada.
College of Arts & Sciences Psychology, University of Tulsa, Tulsa, OK, 74104, USA.
J Pain Res. 2021 Jun 10;14:1653-1665. doi: 10.2147/JPR.S306403. eCollection 2021.
The nociceptive flexion reflex is a physiological, polysynaptic reflex and refers to the level that an appropriate withdrawal response activates when a painful stimulus is detected. The nociceptive flexion reflex threshold (NFRthr) is defined as the lowest noxious stimulation intensity required to trigger a reflex motor response. Despite wide utilization and reports of the NFRthr, there has been no consensus on a standard and/or best method in assessment of the NFRthr.
To systematically review the literature that compared the NFRthr between individuals with fibromyalgia (FM) and healthy controls; and to identify a source of heterogeneity in these trials.
Employing the Cochrane methodology, we systematically searched Ovid MEDLINE, Embase, Cochrane Clinical Answers, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and PsycINFO for clinical case-controlled trials assessing the NFRthr in individuals with and without fibromyalgia from inception to July 2019. Selected articles were passed for data extraction and meta-analyses. We utilized the random-effects model for meta-analysis assuming the true effect size may vary between studies. The sample sizes as a possible source of heterogeneity in multiple meta-regressions were investigated. This systematic review and meta-analysis were registered in PROSPERO before data extraction.
Nine studies met our criteria and were included in the meta-analysis. Methodologies and settings varied between studies, eg, stimulation intensity, duration, and the current increments. Only two articles comprehensively described and reported details about electromyogram amplification, latency, and sampling rate. Evidence from 423 patients with fibromyalgia and 326 healthy individuals suggested that there may not be a meaningful decreased NFRthr in patients (overall mean difference = -3.16; 95% CI:-6.82 to 0.50; Z = 1.69; P=0.09). Published effect sizes were not homogenous (I = 0.91, = 25.04, = 91.22, df = 8, P < 0.00001). The multiple meta-regression analyses indicated that total and female sample sizes might be the main sources of heterogeneity for the effect sizes SS = -0.0570, P = 0.040; SS = -0.0569; P = 0.047.
Evidence suggests that the nociceptive flexion reflex threshold may not be different between patients with fibromyalgia and healthy controls. A unified and rigorous methodology and sample size calculation (probably sex specific investigation) is required for the assessment of nociceptive flexion reflex threshold in patients with fibromyalgia.
伤害性屈曲反射是一种生理性多突触反射，指检测到疼痛刺激时适当的退缩反应所激活的水平。伤害性屈曲反射阈值（NFRthr）被定义为触发反射运动反应所需的最低有害刺激强度。尽管NFRthr得到了广泛应用和报道，但在评估NFRthr的标准和/或最佳方法上尚未达成共识。
系统回顾比较纤维肌痛（FM）患者与健康对照者之间NFRthr的文献；并确定这些试验中异质性的来源。
采用Cochrane方法，我们系统检索了Ovid MEDLINE、Embase、Cochrane临床答案、Cochrane对照试验中央注册库、Cochrane系统评价数据库和PsycINFO，以查找从创刊至2019年7月评估有无纤维肌痛个体的NFRthr的临床病例对照试验。选定的文章进行数据提取和荟萃分析。我们采用随机效应模型进行荟萃分析，假设真实效应大小可能因研究而异。研究了样本量作为多重元回归中异质性可能来源的情况。在数据提取之前，该系统评价和荟萃分析已在PROSPERO中注册。
9项研究符合我们的标准并纳入荟萃分析。研究之间的方法和设置各不相同，例如刺激强度、持续时间和电流增量。只有两篇文章全面描述并报告了关于肌电图放大、潜伏期和采样率的细节。来自423例纤维肌痛患者和326例健康个体的证据表明，患者的NFRthr可能没有有意义的降低（总体平均差异=-3.16；95%CI：-6.82至0.50；Z=1.69；P=0.09）。已发表的效应大小不一致（I²=0.91，Q=25.04，P=91.22，df=8，P<0.00001）。多重元回归分析表明，总样本量和女性样本量可能是效应大小异质性的主要来源（SS=-0.0570，P=0.040；SS=-0.0569；P=0.047）。
证据表明，纤维肌痛患者与健康对照者之间的伤害性屈曲反射阈值可能没有差异。评估纤维肌痛患者的伤害性屈曲反射阈值需要统一且严格的方法和样本量计算（可能是针对性别的研究）。
