[Application of electrophysiological monitoring in acoustic neuroma resection]

Objective: To investigate the neuroprotective effect of facial nerve monitoring on acoustic schwannoma resection and its impact on prognosis. Methods: Eighty patients with acoustic schwannomas were enrolled in our study in the past 2 years and randomly divided into a monitoring group and a non-monitoring group. Tumor size was measured by MRI, and the general condition of the patients were analyzed. The preoperative hearing loss was evaluated, and the facial numbness, post-group related symptoms, and facial paralysis grade were also evaluated before surgery. The monitoring group performed facial nerve monitoring during the operation of auditory schwannomas resection, while the non-monitoring group did not. Both groups decided to perform total or subtotal resection according to the actual conditions during the operation. The hearing status, facial numbness, posterior group related symptoms and facial paralysis grade were evaluated 3 days after surgery, and the prognosis Glasgow outcome score (GOS) was evaluated 1 month after surgery. Results: There were no significant differences between two groups in terms of general condition and preoperative evaluation. There was also no significant difference in surgical methods. But the incidence of facial numbness in monitoring group (42.9%, 15/35) was significantly lower than that in non-monitoring group (86.7%, 39/45) (P<0.001). The facial paralysis grade in monitoring group (17/Ⅰ, 9/Ⅱ, 8/Ⅲ, 1/Ⅳ) was also significantly lower than that of non-monitoring group (1/Ⅰ, 18/Ⅱ, 17/Ⅲ, 9/Ⅳ) (P<0.001). The prognostic score (GOS) in monitoring group (4.60±0.55) was significantly higher than that in non-monitoring group (3.78±0.67)(P<0.001). Conclusion: Facial nerve monitoring can provide better neuroprotection on acoustic schwannoma resection, avoid facial nerve injury, and improve the prognosis quality of life significantly.