面肌痉挛显微血管减压术中异常肌反应监测价值研究

The value of abnormal muscle response monitoring during microvascular decompression for hemifacial spasm

目的探讨异常肌反应(AMR)监测在鉴别责任血管、评估减压效果以及判断预后方面的作用。方法24例面肌痉挛患者接受了术中AMR监测的研究,麻醉诱导后不使用肌松剂。采取刺激面神经颧支,记录同侧颏肌电反应的方法,分析AMR监测结果与术后疗效的关系。结果术中所有患者均记录到特征性的AMR波形。面神经根减压后AMR消失20例,AMR未消失4例。AMR消失的20例患者术后1周17例患者面肌痉挛消失,随访结果20例患者面肌痉挛消失。术中AMR未消失的4例患者术后1周1例患者面肌痉挛消失,随访结果2例患者面肌痉挛消失。经统计学分析AMR消失组的疗效明显好于AMR未消失组。结论术中AMR监测有助于鉴别责任血管,评估即刻减压效果,有助于判断手术的预后,能够显著提高面肌痉挛患者手术的长期效果。

Objective To investigate whether or not intra-operative abnormal muscle response（AMR） monitoring allow us to differentiate the responsible vessel, to assess the effects of decompression during surgery and to predict the postoperative course of hemifacial spasm. Methods In a series of 24 patients operated for hemifacial spasm,the effects of intra-operative evoked EMG monitoring on the surgical procedure was analyzed by use of the clinical and operative patient records. No muscle relaxants were used except before intubation. The zygomatic branch of the facial nerve was stimulated electrically and the records were taken from the ipsilateral mentalis muscle. The relationship between AMR monitoring results and final surgical outcome was analyzed. Results Before incision of the dura mater, all patients showed the characteristic AMR of hemifacial spasm. Of the 20 patients in whom the AMR disappeared during surgery, 17 patients （85%） showed disappearance of hemifacial spasm after MVD operation, 20 patients （100%） showed permanent disappearance of hemifacial spasm; Of the 4 patients in whom the AMR did not disappeared during surgery, 1 patients（25%） showed disappearance of hemifaeial spasm after MVD operation （P=0. 035）, 2 patients （50%） showed permanent disappearance of hemifacial spasm （P=0.022）. The result of AMR disappearance was better than that of AMR existence. Conclusion Intra-operative evoked EMG monitoring is helpful to differentiate the responsible vessel,to assess the effects of decompression during surgery, and to predict the postoperative course of MVD operation. Intra-operative evoked EMG monitoring can improve the long-term results for hemifacial spasm treated with MVD.