Prediction Of Facial Nerve Function After Acoustic Neuroma Resection By Monitoring In FCoMEP And Analysis Of Influencing Factors

Objective:To explore the prediction of short-term and long-term facial nerve function by facial corticobulbar motor evoked potential（FCoMEP）monitoring during acoustic neuroma resection,and to analyze the factors influencing postoperative facial nerve function.To re duce the facial nerve injury and improve the quality of life of patients to provide experience.Methods:From August 2018 to August 2020,FCoMEP was used to monitor the clinical basic information,imaging data,surgical records,electrophysiological monitoring records and other relevant data of patients with acoustic neuroma resection during neurotumor surgery in the First Hospital of Jilin University.The data of outpatient or telephone follow-up at first day,one month,three months,six months and one year after operation were retrospectively analyzed.SPSS 26.0 data analysis software system was used for data statistics and analysis.Through relevant data analysis,the relationship between intraoperative FCoMEP monitoring results and postoperative shor t-term and long-term facial nerve function was explored,as well as other related factors that may affect postoperative facial nerve function Results:Among the 103 patients,20 patients（about 19.4%）were Koos2,40patients（about 38.8%）were Koos3,and 43 patients（about 41.7%）were Koos4.No linear correlation was found between tumor Koos grade and postoperative long-term facial nerve function（P=0.212 > 0.05）.The number of patients with H-B II facial nerve function classification on the 1st postoperative day was the largest,61 cases（about 59.2%）.In the follow-up of one year after surgery,it was found that H-B I patients were the most(65cases（about 63.1%）,followed by H-B II patients in 30 cases（about 29.1%）,and 15 cases（about 14.6%）of patients changed their facial nerve function from H-B III-V to H-B I-II,indicating that within one year after surgery,The recovery of facial nerve function was satisfactory.The first day after surgery,80 patients（about 77.7%）could achieve excellent facial nerve function（H-B I-II）,and 95 patients（about 92.2%）could achieve excellent facial nerve function（H-B I-II）.Only 5 patients（about 4.9%）could achieve acceptable facial nerve function（H-B III）.The improvement of facial nerve function was most obvious at 3-6 months postoperatively.In the time of one year after surgery,the facial nerve function of most patients could be improved from H-B III to H-B I-II,and 6 patients with H-B IV-V facial nerve function first day after surgery did not show significant improvement in facial nerve function one year after surgery.In the 103 patients,FCoMEP could not be measured in one patient,and in the other 102 patients,postoperative and preoperative FCoMEP amplitude ratio was negatively correlated with H-B grade first day and one year after surgery respectively（P<0.05）,that is,the higher the postoperative and preoperative FCoMEP amplitude ratio was,the lower the facial nerve function grade was.The average latency of FCoMEP was10.6±1.7ms,with a range of 6.8-13.7ms.However,there was no correlation between FCoMEP latency and postoperative long-term facial nerve function grade（P > 0.05）.The skilled use of surgical techniques and skilled master y of surgical area anatomy is helpful to the protection of facial nerve.Conclusion:1.The relationship between tumor Koos grade and postoperative longterm facial nerve function grade is uncertain,which may be affected by a variety of factors such as the texture of the tumor,the degree of adhesion between the tumor and the facial nerve,and the surgical technique of the operator.2.The improvement of facial nerve function was most obvious at 3-6months postoperatively.Facial nerve function improved in most patients one year after surgery.3.The amplitude ratio of postoperative and preoperative F Co MEP can predict short-term and long-term facial nerve function to a certain extent,and is more accurate in predicting long-term facial nerve function.4.Mean incubation period of FCoMEP: 10.6±1.7ms;The length of FCoMEP latency period does not predict pos toperative long-term facial nerve function.5.The skilled use of surgical techniques and skilled mastery of surgical area anatomy is helpful to the protection of facial nerve.