异常肌反应形成机制的电生理学研究

Electrophysiological research on mechanism of formation of abnormal muscle response

目的从电生理学角度研究异常肌反应(AMR)形成的机制。方法收集15例接受微血管减压术治疗的特发性面肌痉挛患者的临床资料。术中记录电刺激面神经下颌缘支引起的同侧眼轮匝肌肌电反应(即AMR);电刺激颅内面神经压迫点,分别在面神经下颌缘支以及同侧眼轮匝肌上记录刺激引起的神经传导电位和肌电。分析各波形的潜伏期以及血管减压术后各波形的变化情况。结果刺激面神经下颌缘支时,在眼轮匝肌上记录到的AMR平均潜伏期为(10.49±0.35)ms;刺激颅内面神经压迫点时,下颌缘支诱发电位波形的平均潜伏期为(3.99±0.18)ms,眼轮匝肌肌电波形的平均潜伏期为(4.62±0.32)ms。AMR平均潜伏期大于刺激神经压迫点后在下颌缘支与眼轮匝肌上记录到的波形平均潜伏期之和(P<0.05)。充分减压后,有14例(93.3%)AMR波完全消失。结论压迫血管可能参与了面肌痉挛异常电传导通路,是导致面肌痉挛发作的一个必要因素。

Objective To explore the mechanism of formation of abnormal muscle response（AMR） by electrophysiological methods.Methods The clinical data of 15 patients with idiopathic hemifacial spasm undergoing microvascular decompression were collected.Myoelectricity response（i.e.AMR） was recorded from the orbicularis oculi muscles when the mandibular branch of the facial nerve was electrically stimulated.Conduction potential and myoelectricity response were recorded respectively from the orbicularis oculi muscles and the mandibular branch of the facial nerve when the compression positions of facial nerve were electrically stimulated.The latencies and changes of responses after microvascular decompression were analysed.Results The mean latency of AMR recorded from orbicularis oculi muscles was（10.49±0.35） ms when the mandibular branch of the facial nerve was electrically stimulated.The mean latency of responses recorded from the mandibular branch was（3.99±0.18） ms,and the mean latency of responses recorded from the orbicularis oculi muscles was（4.62±0.32） ms when the compression positions were electrically stimulated.The mean latency of AMR was significantly longer than the sum of the mean latency of responses recorded from the marginal mandibular branch and that recorded from the orbicularis oculi muscles when the compression positions of facial nerve were electrically stimulated（P0.05）.AMR completely disappeared in 14（93.3%） patients after decompression.ConclusionOffending vessels may participate in the abnormal electrical transmission circuit of hemifacial spasm,which is one of the necessary factors leading to hemifacial spasm.