Diffuse noxious inhibitory controls triggered by heterotopic CO2 laser conditioning stimulation decreased the SEP amplitudes induced by electrical tooth stimulation with different intensity at an equally inhibitory rate
Diffuse noxious inhibitory controls triggered by heterotopic CO2 laser conditioning stimulation decreased the SEP amplitudes induced by electrical tooth stimulation with different intensity at an equally inhibitory rate
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DOI：
10.1016/j.pain.2007.07.016
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发表时间：
2008-06-15
期刊：
影响因子：
7.4
通讯作者：
Urnino, Masahiro
中科院分区：
文献类型：
--
作者：
Oono, Yuka;Fujii, Keiko;Urnino, Masahiro
本研究的目的是调查（1）是否有选择性的A δ纤维刺激与CO2激光产生扩散性伤害性抑制控制（DNIC）的效果在三叉神经领域;（2）是否DNIC效果取决于测试刺激强度恒定条件刺激。为了检查手背上的CO2激光辐射是否选择性地刺激A δ纤维，记录激光诱发电位（LEP）。LEP的平均峰潜伏期为381.4ms。结果表明，CO_2激光选择性刺激A δ纤维。以随机顺序对受试者施加3种强度（1.2、1.4、1.6倍痛阈）的电牙齿刺激作为测试刺激，以18 mJ/mm（2）的CO2激光刺激手背4 min作为伤害性条件刺激。记录牙齿电刺激诱发的体感诱发电位（SEP），并使用视觉模拟量表（VAS）评估牙痛强度。SEP晚成分振幅和VAS值仅在条件刺激期间显著降低，无后效。振幅抑制率为31.3%~ 34.6%，VAS值为29.0%~ 31.2%。3种刺激强度的抑制率无显著差异。结果表明，用CO_2激光选择性刺激A δ纤维在三叉神经区域产生DNIC效应，并表明DNIC效应不依赖于测试刺激的强度。(C)2007年国际疼痛研究协会。Elsevier B. V.出版，保留所有权利。
The purpose of this study was to investigate (1) whether selective A delta-fiber stimulation with CO2 laser produces a diffuse noxious inhibitory controls (DNIC) effect in the trigeminal nerve territory; and (2) whether the DNIC effect differs depending on test stimulus intensities under constant conditioning stimuli. To examine whether the CO2 laser radiation on the dorsum of the hand selectively stimulates A delta-fibers, laser evoked potentials (LEP) were recorded. The mean peak latency of LEP was 381.4 ms. The findings revealed that the CO2 laser selectively stimulated A delta-fibers. Electrical tooth stimuli with 3 levels of intensities (1.2, 1.4, 1.6 times the pain threshold) were applied to subjects as test stimulation in randomized order, with a CO2 laser stimulus of 18 mJ/mm(2) applied to the dorsum of the hand for 4 min as the noxious conditioning stimulus. Somatosensory evoked potentials (SEP) induced by electrical tooth stimulation were recorded and tooth pain intensity was evaluated using a visual analogue scale (VAS). The amplitudes of the SEP late component and VAS values were significantly decreased only during the conditioning stimuli without aftereffect. The inhibitory rates of the amplitudes ranged from 31.3% to 34.6% and the VAS values from 29.0% to 31.2%. There were no significant differences in their inhibitory rates between the 3 test stimulus intensities. The result indicated that selective A delta-fiber stimulation with the CO2 laser produces a DNIC effect in the trigeminal nerve territory and suggested that the DNIC effect does not depend on the intensity of the test stimuli. (C) 2007 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.