Altered thermal grill response and paradoxical heat sensations after topical capsaicin application
Altered thermal grill response and paradoxical heat sensations after topical capsaicin application
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DOI：
10.1097/j.pain.0000000000000155
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发表时间：
2015-06-01
期刊：
影响因子：
7.4
通讯作者：
Finnerup, Nanna B.
中科院分区：
文献类型：
--
作者：
Schaldemose, Ellen L.;Horjales-Araujo, Emilia;Finnerup, Nanna B.
热烧烤错觉（其中交错的冷暖条会产生不寻常的灼烧感）和矛盾的热感觉（PHS）（当冷热交替时冷被感知为温暖）是热感觉复杂整合的例子。在这里，我们研究了热敏感神经元的敏化对冷和热整合的影响。我们在 80 名健康参与者的前臂掌侧以随机顺序局部施用辣椒素和媒介物对照（乙醇）后，检查了主要区域（施用部位）的热阈值、PHS 以及对冷（10 摄氏度）和温（40 摄氏度）交替棒（热烤架 [TG]）的热阈值、PHS 以及温暖、寒冷和疼痛感觉。正如预期的那样，辣椒素会引起热痛觉过敏和痛觉过敏，并减少冷痛和冷痛感。此外，我们发现，在施用辣椒素后，TG 引起的疼痛和烧灼感比单独使用 40 摄氏度的棒要少，而对照侧 TG 引起的疼痛和烧灼感更多，这与热烧烤错觉一致。在这两种情况下，TG 期间的疼痛强度与冷痛阈值和热痛阈值均呈负相关，但与检测阈值无关。在施用对照品后，只有 3 名参与者出现了反常的热感，而在施用辣椒素后，有 19 名参与者出现了反常的热感。使用辣椒素后患有PHS的人对冷和热的检测阈值均高于未患有PHS的人，但热痛阈值没有差异。这些结果表明，几个冷热敏感通路之间的复杂串扰塑造了热感知。
The thermal grill illusion, where interlaced warm and cold bars cause an unusual burning sensation, and paradoxical heat sensations (PHS), where cold is perceived as warm when alternating warm and cold, are examples of a complex integration of thermal sensations. Here, we investigated the effect of sensitization Of heat-sensitive neurons on cold and warm integration. We examined thermal thresholds, PHS, and warm, cold, and pain sensations to alternating cold (10 degrees C) and warm (40 degrees C) bars (the thermal grill [TG]) in the primary area (application site) after topical application with capsaicin and vehicle control (ethanol) on the volar forearms in randomized order in 80 healthy participants. As expected, capsaicin induced heat allodynia and hyperalgesia and decreased cold and cold pain sensation. In addition, we found that after capsaicin application, the TG caused less pain and burning than the 40 degrees C bars alone in contrast to the control side where the TG caused more pain and burning, consistent with the thermal grill illusion. In both situations, the pain intensity during the TG correlated inversely with both cold and warm pain thresholds but not with detection thresholds. Paradoxical heat sensation was only seen in 3 participants after control application but in 19 participants after capsaicin. Those with PHS after capsaicin application had higher detection thresholds to both cold and warm than those without PHS, but there was no difference in thermal pain threshold. These results suggest that a Complex cross talk among several cold and warm sensitive pathways shapes thermal perception.