Disrupted offset analgesia distinguishes patients with chronic pain from healthy controls
Disrupted offset analgesia distinguishes patients with chronic pain from healthy controls
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DOI：
10.1097/j.pain.0000000000000989
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发表时间：
2017-10-01
期刊：
影响因子：
7.4
通讯作者：
Kurata, Jiro
中科院分区：
文献类型：
--
作者：
Kobinata, Hiroyuki;Ikeda, Eri;Kurata, Jiro
偏置镇痛（OA）是指在短暂的、暂时性的热疼痛刺激增加后，疼痛感觉不成比例地大幅降低，据报道在神经性疼痛患者中减弱。我们研究了OA是否依赖于偏移前的增量持续时间，以及OA的个体特征是否区分慢性疼痛患者和健康对照组。我们使用Peltier型热刺激器和OA范例，包括在45摄氏度上持续5秒、10秒或15秒的1摄氏度增量（T2）。我们首先检查了OA反应，在左掌前臂，在3个不同的T2的40名健康志愿者，OA和恒定的刺激反应在12例慢性疼痛患者和12名匹配的健康对照。我们测量了OA的幅度（Δ OA）和最大视觉模拟量表（VAS）的潜伏期（时间峰值VAS）在恒定的刺激每一个人。用方差分析比较疼痛感觉动力学，并寻找与心理物理参数的相关性，显著性阈值为P < 0.05。在健康对照中，与5秒时的T2相比，10或15秒时的较长T2导致较大的Δ OA（P = 0.04）。在患者中，在T2 = 5或10秒时，Δ OA显著小于对照组（P = 0.05），但在T2 = 15秒时与对照组相当。患者的最大VAS潜伏期长于对照组，与患者的Delta OA呈负相关。OA指数（Δ OA/[最大VAS潜伏期]）被证明可诊断慢性疼痛，受试者工作特征曲线下面积为0.897。慢性疼痛患者OA受损，疼痛感知的时间锐化减少，这可能意味着内源性疼痛调节系统的可能紊乱。
Offset analgesia (OA) represents a disproportionately large decrease of pain perception after a brief, temporary increment of thermal pain stimulus and was reported attenuated in patients with neuropathic pain. We examined whether OA depends on the increment duration before offset, and whether individual features of OA distinguish patients with chronic pain and healthy controls. We used a Peltier-type thermal stimulator and OA paradigms including 5-, 10-, or 15-s duration of 1 degrees C-increment (T2) over 45 degrees C. We first examined OA response, on the left volar forearm, at 3 different T2's in 40 healthy volunteers, and OA and constant stimulus responses in 12 patients with chronic pain and 12 matched healthy controls. We measured magnitude of OA (Delta OA) and maximum visual analogue scale (VAS) latency (time to peak VAS) during constant stimulus for each individual. Pain perception kinetics were compared with analysis of variance and sought for correlations with psychophysical parameters with a significance threshold at P < 0.05. In healthy controls, longer T2 at 10 or 15 seconds resulted in larger Delta OA compared with T2 at 5 seconds (P = 0.04). In patients,Delta OA was significantly smaller than controls at T2 = 5 or 10 seconds (P = 0.05) but grew comparable at T2 = 15 seconds with controls. Maximum VAS latency was longer in patients than in controls and negatively correlated with Delta OA in patients. An OA index (Delta OA/[ maximum VAS latency]) proved diagnostic of chronic pain with an area under the receiver operating characteristic curve at 0.897. Patients with chronic pain showed impairment of OA and reduced temporal sharpening of pain perception, which might imply possible disturbance of the endogenous pain modulatory system.