SURG-34. INTRAOPERATIVE CORTICOBULBAR MOTOR EVOKED POTENTIALS RELIABLY PREDICT FACIAL NERVE FUNCTION IN ELDERLY PATIENTS WITH CEREBELLOPONTINE ANGLE TUMORS. A CLINICAL AND NEUROPHYSIOLOGY STUDY

Abstract BACKGROUND Cerebellopontine angle (CPA) surgery for extra-axial lesions in elderly patients could be hampered by concerns regarding functional outcomes. However, an overall ageing society warrants improved approach. Intraoperative neuromonitoring is crucial facial nerve (FN) preservation: intraoperative cortico-bulbar motor evoked potentials (FMEPs) can effectively coupled to standard techniques. In a previous work, we validated the use of FMEPs as preditors early and late post-operative FN function (FNF). Aim this study was re-evaluate FMEP role beyond 65 years age. METHODS An institutional series 83 reported. A pair needle electrodes used record from orbicularis oculi (OOc) oris (OOr) muscles; baseline, final minimum values were recorded. From amplitudes, minimum-to-baseline (MBR) final-to-baseline (FBR) amplitude ratios, recovery value (RV=FBR-MBR), calculated. These indices correlated (at discharge) 1-year) FNF. RESULTS 23 (27.7%) older than years. Among these, 52.2% 81% had good FNF, respectively. Early FNF not associated age (p > 0.99 p=0.72, respectively). patients, higher FBR (from OOc OOr) MBR OOc) (p=0.01, p=0.009, p=0.03, Conversely, OOr only parameter significantly with (p=0.049). ROC analysis confirmed that, most accurate index predicting measured (AUC=0.869, cut-off 12.5%). The (AUC=0.865). CONCLUSION Cortico-bulbar are reliable predictors allow safe feasible important cohort.