2026 Proffered Presentations
S070: PREDICTORS OF FACIAL NERVE DYSFUNCTION IMPROVEMENT AND 6-MONTH OUTCOMES FOLLOWING RESECTION OF VESTIBULAR SCHWANNOMAS
Rithvik Ramesh, BA1; Lourdes Kaufman, BA1; Ruben Hernandez, BS1; Stephanie Younan, BS, MPH1; Nadeem Al-Adli, MD2; Philip V Theodosopoulos, MD1; Steven W Cheung, MD1; Nicole T Jiam, MD1; Ramin A Morshed, MD1; 1University of California, San Francisco; 2University of North Carolina at Chapel Hill
Introduction: Facial nerve (FN) dysfunction after vestibular schwannoma resection significantly impairs quality of life but remains difficult to predict. We therefore evaluated the predictors and typical time course of FN functional recovery from discharge to 6 months, and constructed prognostic nomograms to estimate individualized risk.
Methods: We retrospectively reviewed patients who underwent vestibular schwannoma resection at a large urban tertiary care center between 2004 and 2024. FN function was graded using the House-Brackmann (HB) scale at discharge, 3 months, and 6 months postoperatively. Six-month outcomes were categorized as no dysfunction (HB I), mild palsy (HB II-III), moderate palsy (HB IV-V), or complete palsy (HB VI). Among patients discharged with HB II–V, recovery was defined as improvement by at least one HB grade. Demographic, clinical, and tumor characteristics were compared between outcome groups using appropriate parametric and non-parametric tests. Variables with p<0.20 on univariate analysis were included in multivariable logistic regression to identify independent predictors, with adjusted odds ratios (aOR) and 95% confidence intervals (CI) reported. Separate nomograms were developed to predict the probability of severe palsy at 6 months and FN recovery from discharge, with performance assessed using 10 iterations of 70/30 Monte Carlo cross-validation and summarized by mean area under the curve (AUC).
Results: HB grades were available at discharge for 321 patients, of whom 48.0% had no FN dysfunction (HB I), 34.9% had mild palsy (HB II–III), 10.3% had moderate dysfunction (HB IV-V), and 6.9% had complete palsy (HB VI). At 6 months, outcomes were available for 220 patients: 93.1% achieved HB I–V, while 6.4% remained at HB VI. Among 86 patients discharged with HB II–V, 80.2% demonstrated at least one-grade functional improvement, with the majority achieving this improvement by the 3-month follow-up.
Patients with complete palsy at 6 months had significantly larger mean tumor volume (18.4 cm³ vs 8.2-15.1 cm3; p<0.001), higher rates of preoperative hydrocephalus (38.5% vs 14.8-36.4%; p=0.034), more frequent macrocystic features (53.8% vs 16.0-27.3%; p=0.003), and worse FN grades at discharge (p<0.001). Patients who improved from discharge had smaller tumors (10.0±9.0 vs 12.9±7.3 cm³; p=0.047) compared to those with no improvement.
On multivariable analysis, the only independent predictor of severe palsy at 6 months was higher HB grade at discharge (aOR 4.50 per point; 95% CI, 2.42–12.60). No independent predictors of FN improvement were identified. Nomograms predicting 6-month severe palsy and FN improvement achieved mean AUCs of 0.98±0.02 and 0.63±0.08, respectively.
Conclusions: Most patients achieved favorable FN function by three months after vestibular schwannoma resection. FN function at discharge was the strongest predictor of six-month outcome and a predictive nomogram for six-month FN outcome demonstrated excellent discriminatory performance. However, no reliable predictors of improvement from discharge were identified. These findings highlight the importance of facial nerve preservation strategies, early postoperative functional assessment for prognostication, and further research into mechanisms of recovery.
