经颅电刺激面神经运动诱发电位在小脑脑桥角区肿瘤手术中的应用

Intraoperative facial motor evoked potential monitoring with transcranial electrical stimulation during cerebellopontine angel area tumor sugery

目的探讨静吸复合麻醉下经颅电刺激面神经运动诱发电位（FNMEP）监测在小脑脑桥角（CPA）区肿瘤手术中是否可预测术后面神经功能。方法52例CPA区肿瘤患者，术中行FNMEP监测面神经功能，术后参照H—B面神经分级标准，对术前、后面神经功能的改变和FNMEP波幅术后／术前比率之间的关系进行统计分析。结果FNMEP波幅变化与术后面神经功能差异有统计学意义（P〈0．001）。FNMEP波幅比率〈50％，预示术后面神经功能障碍；比率〉50％，预示术后面神经功能正常或仅为轻度功能障碍（H—BI级或Ⅱ级）。结论FNMEP可预测术后面神经功能，可对现有术中面神经功能的监测技术起到完善、补充的作用。

Objective To determine whether monitoring facial nerve motor- evoked potential （FNMEP） elicited by transcranial electrical stimulation during cerebellopontine angel （CPA） tumor surgery is useful for predicting postoperative facial nerve outcome. Methods In 52 patients undergoing CPA tumor surgery, FNMEP was delivered through transcranial electrical stimulation. FNMEP was recorded from the oris muscles and the mentalis muscles. The correlation between the final - to - baseline ratio and 7 days postoperative facial nerve function was examined. Preoperative and postoperative functions were documented using the House- Brackmann grading system. Spearman correlation coefficients were used to evaluate whether the postoperative facial fuction was correlated with the FNMEP ratio in patients with CPA tumor. Resluts The valid FNMEPs were obtained in 50 of the 52 recordings from the orbicularis oris muscle in the group of patients with CPA tumor. The postoperative facial nerve function was correlated significantly with the FNMEP ratio in the orbicularis oris muscles （ P 〈 0. 001 ）. An FNMEP rate of 〈 50% consistently predicted postoperative facial palsy. If the FNMEP ratio remained at 〉 50% , all patients bad satisfactory facial nerve function （House and Brackmann grades ｜ and II ）. Using 50% of baseline amplitude criteria, significant facial deficits were predicted with a sensitivity/specificity of 1.00/0. 88. Conclusions Introperative FNMEP monitoring could provide an ongoing surgeon - independent of facial nerve function and be useful for predicting facial nerve function after CPA tumor surgery. This method should be used as an adjunct to direct electrical facial nerve stimulation and continuous electromyographic monitoring of facial nerve target muscles.