三叉神经8分区电刺激的临床研究

Clinical research of eight areas of trigeminal nerves with electrical stimulation

目的利用电生理监测技术对正常三叉神经根进行监测，研究其感觉和运动纤维的分布规律。方法收集广东省第二人民医院自2011年1月至2013年12月收治的原发性面肌痉挛行微血管减压患者20例患者进行研究。术中首先将三叉神经根分为8个区域，Ⅰ为外侧区，Ⅱ为外上区，Ⅲ为中上区，Ⅳ为内上区，Ⅴ为内侧区，Ⅵ为内下区，Ⅶ为中下区，Ⅷ为外下区，然后采用直径1mm的双极刺激器，分别予0．2mA的电刺激，在眶上孔（V1）、眶下孔（V2）、颏孔（V3）记录复合神经动作电位（CNAP），在咬肌（MM）和颞肌（TM）记录复合肌肉动作电位（CMAP），根据CNAP和CMAP出现的规律来判断三叉神经根内感觉和运动纤维的分布规律。结果所有患者术中电刺激三叉神经根均能在外周记录到稳定的CNAP和CMAP波形；三叉神经根Ⅰ、Ⅱ、Ⅷ区内CNAPV1、CNAPV2、CNAPV3和CMAPMM、CMAPTM均较少出现，而于Ⅳ、Ⅴ、Ⅵ区出现最多，差异有统计学意义（P〈0．051。刺激感觉主根纤维主要记录到CNAP，刺激运动主根纤维记录到CMAP的同时可记录到V1、V2、V3-支或多支的CNAP。结论（1）根据电生理监测结果，三叉神经运动与感觉纤维存在吻合纤维。（2）借助三叉神经8分区方法可以判断运动纤维位于神经的内侧区域，感觉纤维位于中部及外侧区域。

Objective To study the distribution rule of sense and motor fibers in the normal trigeminal nerve roots by electrophysiologic monitoring. Methods Twenty patients accepted microvascular decompression because of primary mimetic convulsion, collected in our hospital from January 2011 and December 2013, was studied their normal trigeminal nerve roots through electroneurophysiology; during the operation, the trigeminal nerve roots were divided into 8 areas： I area is the external lateral area, II area is the external upper area, Ill area is the middle upper area, IV area is the internal upper area, V area is the internal lateral area, VI area is the internal bottom area, VII area is the middle bottom area, and VIII area is the external bottom area; and then, one mm diameter bipolar stimulator was adopted to give 0.2 mA electrical stimulation on these areas, respectively; and the compound nerve action potential （CNAP） at the foramina supraorbitale （V1）, foramina infraorbitale （V2） and foramina mentale （V3） was recorded as the CNAPvl, CNAPw and CNAPv3 respectively; the compound muscle action potential （CMAP） at the masseter muscle （MM） and temporal muscle （TM） was recorded as CMAP~ and CMAPa~ respectively; and finally, the distribution rules of the sense and motor fibers inside the trigeminal nerve roots were judged according to the laws of CNAP and CMAP emergence. Results During the operation, all patients could get stable CNAP and CMAP wave patterns at periphery according to the electrical stimulation on trigeminal nerve roots; the CNAPV1, CNAPv2 and CNAPV3, CMAPMM and CMAPTM seldom appeared in the Ⅰ, Ⅱ and Ⅷ areas of trigeminal nerve roots, but more often appeared in the Ⅳ, Ⅴ and Ⅵ areas, enjoying significant differences （P〈0.05）;motor fiber located in the internal lateral area of the nerve, and the sense fiber located in the middle and external lateral area. By stimulating the sense taproot fiber, CNAP could be recorded, and by stimulation the motor taproot fiber, CMAP and several CNAP from V1, V2 and V3 could be recorded. Conclusion Electrical stimulation on motor taproot implies that there are anastomosing fibers existting in both motor and sense fibers; according the 8 areas being divided, motor fiber locating in the internal lateral area of the nerve, and sense fibers locating in the middle and external lateral areas can be concluded.