Efficacy of a Quantitative Intra‐Operative Facial Nerve Continuous Monitoring System for Functional Preservation Following Intratemporal Facial Nerve Schwannoma Resection

ABSTRACT Objective Preservation of the facial nerve is critical in surgery for facial nerve schwannoma. Intra‐operative monitoring systems typically assess facial nerve function by delivering intermittent electrical stimulation through electrodes; however, this approach cannot effectively achieve continuous stimulation and quantitative assessment. This study aimed to assess the efficacy of a quantitative intra‐operative facial nerve continuous monitoring system for preserving post‐operative facial nerve function. Methods Ten patients who underwent continuous nerve monitoring using this system during surgery for facial nerve schwannoma were included. Clinical data, electrode placement sites, and pre‐ and postoperative facial nerve function assessed using the House–Brackmann grading system were retrospectively analyzed. In patients with conductive hearing loss, postoperative hearing outcomes were also analyzed. Results Facial nerve function was preserved in all patients, except for one patient who experienced transient postoperative functional deterioration. In several cases, conductive hearing loss improved following schwannoma resection. Conclusion Continuous and quantitative monitoring of facial nerve function is a reliable intraoperative evaluation that may help prevent unexpected facial nerve injury. This system represents a valuable tool for application in facial nerve schwannoma surgeries. Level of Evidence Level 4