Effects of deep pain of masticatory and neck/shoulder muscles to the tactile sensation from orofacial region and modification effect of autonomic nerve activation

咀嚼肌和颈肩肌深部疼痛对口面部触觉的影响及自主神经激活的修正作用

• 批准号: 14571865
• 负责人: NARITA Noriyuki
• 金额: $ 2.56万
• 依托单位: Nihon University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14571865/
• 关键词: Masticatory muscle pain; Neck; shoulder muscle pain; Air puff stimulation; Somatosensory evoked potential; Hypertonic saline; Cold pressor; Lip; Tactile sensation; air puff; 体性感覚誘発電位; 咀嚼筋・肩筋痛; 手指冷却; 感覚過敏; 感覚鈍麻

Aim : This study was investigated whether somatosensory cortex activity, evoked by air puff stimulation of the lower lip region, could be modulated by experimental masticatory and/or neck/shoulder muscles pain, and by hand immersion in cold water.Methods : Air puff stimulation, was applied to evoke tactile sensation from the lower lip surface. Somatosensory evoked potentials (SBPs) were recorded from C3, C4, and Cz positions. Masticatory muscle pain and neck/shoulder muscle pain was evoked by the injection of isotonic (0.9%, 0.5ml) and hypertonic saline (5%, 0.5ml) into the left masseter muscle and trapezius muscle, respectively. As cold pressor test, left hand was immersed into cold water (4℃).Results : SBPs were composed of two wave factors, N20 and P30. By injecting isotonic saline into the masseter and trapezius muscles, amplitudes of N20 and P30 and peak-to-peak amplitudes of N20/P30 were not significantly altered. On the other hand, peak amplitudes of N20 and P30 and peak-to-peak amplitude of N20/P30 were significantly decreased during the first phase of the post-injection period of hypertonic saline into masseter muscle. However, there were no significant alterations in SBPs during the injection of hypertonic saline into trapezius muscle. These results present further evidences for the pathofunctional interrelationship between masticatory muscle pain and modulation of homotopical tactile input on the bases of quantitative analyses of SEPs. We also analyzed the effect of the hand immersion into cold water (4℃) on the tactile sensation from the orofacial region and it was clarified that the tactile sensation from the lip surface was significantly enhanced by the cold pressor test.Conclusions : Masticatory muscle pain may diminish the tactile sensation from the homotopical orofacial region depending on the severity of pain, while the sympathetic nerve activation may enhance the tactile sensation of the orofacial region.

目的：研究实验性咀嚼和(或)颈肩部肌肉疼痛和手浸冷水是否能调节下唇区的体感皮层活动。方法：应用吹气刺激，从下唇表面诱发触觉。在C3、C4和Cz位置记录体感诱发电位(SBPs)。左侧咬肌和斜方肌分别注射等渗盐水(0.9%，0.5ml)和高渗盐水(5%，0.5ml)，分别诱发咀嚼肌痛和颈肩肌痛。作为冷加压试验，左手浸泡在冷水中(4℃)。结果：SBPS由N20和P30两个波因子组成。咬肌、斜方肌注射等渗盐水后，N20、P30波幅及N20/P30波幅无明显改变。而N20、P30波幅及N20/P30波峰间波幅在高渗盐水注射后第一时相显著降低。而斜方肌内注射高渗盐水后，SBP无明显变化。这些结果在SEPs定量分析的基础上，为咀嚼肌疼痛与同位触觉输入调制之间的病理功能相互关系提供了进一步证据。我们还分析了手浸入冷水(4℃)对口面部触觉的影响，结果表明，冷加压试验显著增强了唇面的触觉。结论：咀嚼肌疼痛可能会减弱同位口面部的触觉，这取决于疼痛的严重程度，而交感神经的激活可能会增强口面部的触觉。