2026 Proffered Presentations
S064: A MATCHED-COHORT ANALYSIS OF PREOPERATIVE HEARING IN NF2-ASSOCIATED AND SPORADIC VESTIBULAR SCHWANNOMAS
Stephanie M Younan, MPH, BS; Lourdes Kaufman, BA; Rithvik Ramesh, BA; Ruben Hernandez, BS; Nadeem Al-Adli, MD; Philip V Theodosopoulos, MD; Steven W Cheung, MD; Brian Na, MD, PhD; Ramin Morshed, MD; Nicole T Jiam, MD; UCSF
Introduction: Neurofibromatosis type 2 (NF2) is characterized by bilateral vestibular schwannomas (VS) and presents unique management challenges compared to sporadic, unilateral VS. While hearing preservation is a primary goal, comprehensive comparisons of the preoperative audiometric burden between these populations remain limited Importantly, differing management pathways, where NF2 patients are more likely to receive treatments like radiation or bevacizumab prior to resection, can confound hearing assessments. Evaluating the preoperative hearing status in treatment-naive patients is therefore critical to understanding the intrinsic impact of each disease entity. This study aims to characterize and compare the preoperative bilateral hearing status in radiation-naïve NF2-associated versus sporadic VS.
Methods: A retrospective review was conducted of patients who underwent VS resection at a tertiary care center between 2010 and 2024. Patients were stratified by etiology (NF2-associated vs. sporadic). To isolate the intrinsic effect of NF2 on hearing, a 1:8 volume-matched analysis was performed on a primary cohort of radiation-naive patients. Preoperative audiometric data, including bilateral pure tone averages (PTA) and word recognition scores (WRS), were analyzed. The primary outcome was the preoperative hearing thresholds in both the surgical and contralateral ears. Statistical comparisons were performed using Mann-Whitney U tests with effect size calculations (Cohen's d).
Results: A volume-matched, radiation-naive analysis yielded a cohort of 16 NF2 patients and 123 sporadic counterparts with statistically identical tumor volumes (median 7.7 cm3 vs. 8.8 cm3, p=0.958). NF2 patients were significantly younger (mean age 33.6 vs. 50.2 years, p<0.001). Within this controlled cohort, NF2 patients demonstrated significantly worse hearing in the surgical ear (median PTA 99.2 vs. 45.0 dB HL, p=0.020), representing a moderate-to-large clinical effect (Cohen's d=0.67). AAO-HNS hearing classification analysis showed a trend toward NF2 patients presenting with poorer hearing (Classes C-D), with 1.7-fold lower odds of serviceable hearing at presentation (OR=0.44, 95% CI: 0.13-1.47, p=0.265). Notably, consistent with the pathophysiology of the disease, 47% of NF2 patients presented with significant contralateral hearing impairment, underscoring a pattern of bilateral auditory involvement not seen in sporadic cases.
Conclusion: After controlling for both tumor volume and prior radiation exposure, patients with NF2-associated vestibular schwannomas demonstrate substantially greater hearing impairment in the ipsilateral ear compared to those with sporadic tumors. This finding suggests an intrinsic auditory neuropathy in NF2-related schwannomatosis that is independent of tumor volume or prior treatment effects. The coexisting contralateral hearing loss further underscores the limited auditory reserve in this population, a critical factor for surgical planning and patient counseling. These findings highlight the distinct clinical presentation of NF2 and support the development of management protocols tailored to its unique bilateral auditory challenges.
