经颅磁刺激对夜磨牙患者咬肌运动诱发电位的研究

The masseter motor-evoked potential after transcranial magnetic stimulation in patients with sleep bruxism

目的:比较夜磨牙患者与正常对照组经颅磁刺激(TMS)下产生的咬肌运动诱发电位(MEP)的异同。方法:纳入30名夜磨牙患者及30名健康志愿者,单脉冲TMS大脑皮层面部运动区域,记录咬肌MEP,分析比较2组MEP的各项参数。试验均在白天受试者清醒的状态下进行。结果:夜磨牙组咬肌MEP的激发阈值(130%AMT)为53%,对侧MEP(c-MEP)的潜伏期为(6.7±1.3)ms、波幅为0.19(0.15,0.29)mV,三叉神经根MEP(r-MEP)的潜伏期为(2.3±0.4)ms,中枢传导时间(CCT)为4.4(3.3,5.2)ms;正常对照组AMT为52(52,55)%,c-MEP的潜伏期为(6.4±0.7)ms、波幅为0.23(0.17,0.28)mV,r-MEP的潜伏期为(2.4±0.4)ms,CCT为4.0(3.4,4.4)ms,2组咬肌运动诱发电位各项参数均无统计学差别。结论:与正常人相比较,夜磨牙患者大脑皮层运动系统兴奋性未见明显改变。

Objective：To study the masseter motor evoked potential（MEP）in patients with sleep bruxism（SB）and in healthy con-trols.Methods：30 subjects with SB and 30 healthy controls were included.MEPs were obtained by transcranial magnetic stimulation （TMS）.Tests were done during daytime when the subjects were awake.The data were statistically analysed.Results：In the patients AMT was 55（52,55）%,latency of c-MEP （6.7 ±1.3）ms,the amplitude of c-MEP 0.19（0.15,0.29）mV,latency of r-MEP （2.3 ±0.4）ms,the central conduction time（CCT）4.4（3.3,5.2）ms.In the control subjects AMT was 52（52,55）%,latency of c-MEP （6.4 ±0.7）ms,the amplitude of c-MEP 0.23（0.17,0.28）mV,latency of r-MEP （2.4 ±0.4）ms,CCT 4.0 （3.4,4.4） ms.No significant difference was found between the 2 groups in the measurements evoked by TMS.Conclusion：The MEP after TMS in patients with SB is similar to that of healthy subjects,indicating that the excitability of the cortical motor system is not changed in bruxism subjects,at least when evaluated by TMS.