Research Center on Aging, CIUSSS de l'Estrie-CHUS, Sherbrooke, Québec, Canada.
Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada.
PLoS One. 2024 Jul 25;19(7):e0307556. doi: 10.1371/journal.pone.0307556. eCollection 2024.
Quantitative sensory tests (QST) are frequently used to explore alterations in somatosensory systems. Static and dynamic QST like pain threshold and temporal summation (TS) and conditioned pain modulation (CPM) are commonly used to evaluate excitatory and inhibitory mechanisms involved in pain processing. The aim of the present study was to document the reliability and the minimal detectable change (MDC) of these dynamic QST measurements using a standardized experimental paradigm.
Forty-six (46) pain-free participants took part in 2 identical sessions to collect TS and CPM outcomes. Mechanical (pressure pain threshold [PPT]) and thermal (constant 2-minute heat pain stimulation [HPS]) nociceptive stimuli were applied as test stimuli, before and after a cold-water bath (conditioning stimulus). TS was interpreted as the change in pain perception scores during HPS. CPM were determined by calculating the difference in pain perception between pre- and post- water bath for both PPT and HPS. Relative and absolute reliability were analyzed with intra-class correlation coefficient (ICC2, k), standard error of the measurements (SEMeas) and MDC.
Results revealed a good to excellent relative reliability for static QST (ICC ≥ 0.73). For TS, a poor to moderate relative reliability depending on the calculation methods (ICC = 0.25 ≤ ICC ≤ 0.59), and a poor relative reliability for CPM (ICC = 0.16 ≤ ICC ≤ 0.37), both when measured with mechanical stimulation (PPT) and thermal stimulation (HPS). Absolute reliability varied from 0.73 to 7.74 for static QST, 11 to 22 points for TS and corresponded to 11.42 points and 1.56 points for thermal and mechanical-induced CPM, respectively. MDC analyses revealed that a change of 1.58 to 21.46 point for static QST, 31 to 52 points for TS and 4 to 31 points for CPM is necessary to be interpreted as a real change.
Our approach seems well-suited to clinical use. Although our method shows equivalent relative and absolute reliability compared to other protocols, we found that the reliability of endogenous pain modulation mechanisms is vulnerable, probably due to its dynamic nature.
定量感觉测试（QST）常用于探索躯体感觉系统的变化。 常用的静态和动态 QST，如痛阈和时间总和（TS）和条件性疼痛调制（CPM），用于评估参与疼痛处理的兴奋性和抑制性机制。本研究的目的是使用标准化实验范式记录这些动态 QST 测量的可靠性和最小可检测变化（MDC）。
46 名无痛参与者参加了 2 次相同的会议，以收集 TS 和 CPM 结果。在冷浴（条件刺激）前后，应用机械（压痛阈值 [PPT]）和热（恒 2 分钟热痛刺激 [HPS]）伤害性刺激作为测试刺激。TS 被解释为 HPS 期间疼痛感知评分的变化。CPM 通过计算水疗前后 PPT 和 HPS 之间的疼痛感知差异来确定。使用组内相关系数（ICC2，k）、测量标准误差（SEMeas）和 MDC 分析相对和绝对可靠性。
结果显示，静态 QST 的相对可靠性良好至优秀（ICC≥0.73）。对于 TS，根据计算方法，相对可靠性较差至中等（ICC=0.25≤ICC≤0.59），CPM 的相对可靠性较差（ICC=0.16≤ICC≤0.37），机械刺激（PPT）和热刺激（HPS）均如此。静态 QST 的绝对可靠性从 0.73 到 7.74，TS 为 11 到 22 点，分别对应于热和机械引起的 CPM 的 11.42 点和 1.56 点。MDC 分析显示，静态 QST 变化 1.58 至 21.46 点、TS 变化 31 至 52 点和 CPM 变化 4 至 31 点需要被解释为真正的变化。
我们的方法似乎适合临床应用。虽然我们的方法与其他方案相比具有相当的相对和绝对可靠性，但我们发现内源性疼痛调制机制的可靠性很脆弱，可能是由于其动态性质。
