Temporal aspects of endogenous pain modulation during a noxious stimulus prolonged for 1 day
Temporal aspects of endogenous pain modulation during a noxious stimulus prolonged for 1 day
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DOI：
10.1002/ejp.1523
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发表时间：
2020-01-21
影响因子：
3.6
通讯作者：
Graven-Nielsen, Thomas
中科院分区：
文献类型：
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作者：
Hoeger Bement, Marie;Petersen, Kristian K.;Graven-Nielsen, Thomas
本研究调查了(a)健康成人持续的有害刺激（24小时外用辣椒素）是否会损害中枢性疼痛抑制和促进系统（测量为条件疼痛调节（CPM）的减少和疼痛的时间累积（TSP）的增强），以及(b)在持续的有害刺激期间急性疼痛缓解或加剧（冷却和加热辣椒素贴片）是否会影响中枢性疼痛调节。方法28名参与者（26.2 +/- 1.0岁；12名女性）在前臂涂上8%辣椒素透皮贴片24小时。在基线（第0天）、1小时、3小时、第1天（辣椒素应用后）和第3/4天（辣椒素去除后）收集数据，包括辣椒素引起的疼痛强度、热痛阈值（HPTs）、TSP（腿部疼痛袖带压力刺激10次）和CPM（腿部疼痛袖带压力调节前与对侧腿部疼痛袖带压力调节期间）。3小时后，对辣椒素贴片施加冷（12摄氏度）和热（42摄氏度）刺激，以短暂地增加和减少疼痛强度。参与者报告在1小时（2.5 +/- 2.0）、3小时（3.7 +/- 2.4）和第1天（2.4 +/- 1.8）时的中度疼痛评分。与第0天相比，辣椒素作用后3小时CPM降低（p = 0.001），并且在辣椒素疼痛评分降低（0.4 +/- 0.7,p < 0.001）和增加（6.6 +/- 2.2,p < 0.001）的同时仍然降低。与初始3HR相比，斑块冷却或加热期间的CPM没有显著差异；然而，与贴片冷却相比，贴片加热时的CPM降低（p = 0.01）。TSP和HPT没有变化。结论该延长的实验疼痛模型有助于了解亚急性疼痛状况，并可能有助于了解从急性到慢性疼痛的转变。在健康成人的早期长时间有害刺激中，CPM的疗效降低，并且不能通过暂时消除持续的疼痛来恢复，这表明神经可塑性过程的动态程度较低。
Background This study investigated (a) if a prolonged noxious stimulus (24-hr topical capsaicin) in healthy adults would impair central pain inhibitory and facilitatory systems measured as a reduction in conditioned pain modulation (CPM) and enhancement of temporal summation of pain (TSP) and (b) if acute pain relief or exacerbation (cooling and heating the capsaicin patch) during the prolonged noxious stimulus would affect central pain modulation. Methods Twenty-eight participants (26.2 +/- 1.0 years; 12 women) wore a transdermal 8% capsaicin patch on the forearm for 24 hr. Data were collected at baseline (Day 0), 1 hr, 3 hr, Day 1 (post-capsaicin application) and Day 3/4 (post-capsaicin removal) that included capsaicin-evoked pain intensity, heat pain thresholds (HPTs), TSP (10 painful cuff pressure stimuli on leg) and CPM (cuff pressure pain threshold on the leg prior vs. during painful cuff pressure conditioning on contralateral leg). After 3 hr, cold (12 degrees C) and heat (42 degrees C) stimuli were applied to the capsaicin patch to transiently increase and decrease pain intensity. Results Participants reported moderate pain scores at 1 hr (2.5 +/- 2.0), 3 hr (3.7 +/- 2.4), and Day 1 (2.4 +/- 1.8). CPM decreased 3-hr post-capsaicin (p = .001) compared to Day 0 and remained diminished while the capsaicin pain score was reduced (0.4 +/- 0.7, p < .001) and increased (6.6 +/- 2.2, p < .001) by patch cooling and heating. No significant differences occurred for CPM during patch cooling or heating compared to initial 3HR; however, CPM during patch heating was reduced compared with patch cooling (p = .01). TSP and HPT did not change. Conclusions This prolonged experimental pain model is useful to provide insight into subacute pain conditions and may provide insight into the transition from acute to chronic pain. Significance During the early hours of a prolonged noxious stimulus in healthy adults, CPM efficacy was reduced and did not recover by temporarily removing the ongoing pain indicating a less dynamic neuroplastic process.