Sudden Hearing Loss as an Initial Symptom of Vestibular Schwannoma.

Abstract

This study aims to determine the prevalence of vestibular schwannoma (VS) among patients presenting with sudden hearing loss (SHL) and to characterize the clinical features of individuals diagnosed with both VS and SHL. We conducted an observational retrospective review at a tertiary referral center, spanning a 30-year period, focusing on patients diagnosed with SHL where VS was confirmed as the underlying cause. We included patients meeting these criteria while excluding those lacking imaging or with a pre-existing diagnosis of VS. We evaluated the audiological characteristics at the time of diagnosis and assessed clinical outcomes following treatment. Among the 403 patients presenting with SHL during the study period, 9 (2.2%) were diagnosed with VS, aged between 25 and 72 years. Although audiometric profiles varied, high-frequency hearing loss predominated, mostly categorized as mild to moderate. Six patients (66%) had Koos grade I-II schwannomas. Only 2 patients achieved complete hearing recovery post-treatment, while 4 showed no improvement. VS is a rare etiology of SHL, accounting for slightly over 2% of cases. Its symptomatology, severity, and audiometric patterns do not significantly differ from SHL caused by other factors. Tumor size does not correlate with hearing characteristics. Treatment modalities resemble those for other SHL cases, and hearing improvement does not obviate the necessity for follow-up magnetic resonance imaging (MRI) scans.