Progression of Contralateral Hearing Loss in Patients With Sporadic Vestibular Schwannoma

Abstract

Background and Introduction: Vestibular schwannomas (VSs) are the most common tumors of the cerebellopontine angle, typically presenting unilaterally with ipsilateral sensorineural hearing loss (SNHL). The mechanism of tumor-induced hearing loss has recently been shown to be related to secreted tumor factors, in addition to mechanical compression of the adjacent auditory nerve, and these factors may percolate through CSF or blood to affect contralateral hearing as well. Methods: This is a retrospective study of medical records for patients treated for VS at Mass Eye and Ear from January 1994 through October 2018. Included patients had unilateral VS and sequential audiometry allowing for longitudinal assessment of hearing over time. Mass Eye and Ear's audiology database was used to select age-and sex-matched case controls, also with sequential audiometry, from the non-VS population. Subgroup analysis was performed by age, sex, baseline hearing, and tumor size at initial diagnosis. Hearing loss progression was performed using Kaplan-Meier analysis to account for variable follow-up times. Results: A total of 661 patients were identified with VS and sequential audiometry. The population was predominantly female vs. male (368 vs. 293, p = 0.0035), driven primarily by younger patients with Koos 4 tumors (76 female vs. 49 male, p = 0.016). Patients with normal baseline hearing bilaterally (N = 241) demonstrated no significant difference in hearing loss progression in VS-contralateral vs. control ears. Patients with abnormal baseline VS-ipsilateral hearing (N = 190), however, demonstrated significantly higher likelihood of reaching moderate SNHL in VS-contralateral ears. Subgroup analysis by age, sex, and baseline tumor size did not yield any subgroup-specific trends for hearing loss progression. Discussion and Conclusion: This is the largest study to date tracking long-term bilateral hearing outcomes in patients with VS, and demonstrates that, in patients with abnormal hearing in the VS-ipsilateral ear, there exists a long-term risk of progression to moderate hearing loss in the contralateral ear as well. Combined with the absence Early et al. Vestibular Schwannoma Contralateral Hearing Loss of significant changes in word understanding in the affected ears, these findings may provide clues to the nature of tumor-secreted factors involved in VS-associated hearing loss. Female predominance within the VS patient population is confirmed, driven mostly by younger female patients with Koos 4 tumors.

Losartan prevents tumor-induced hearing loss and augments radiation efficacy in NF2 schwannoma rodent models

“…stm.sciencemag.org/cgi/content/full/13/602/eabd4816/DC1 Materials and Methods Figs. S1 to S9 Tables S1 to S11 Data file S1 References (81)(82)(83)(84)(85)(86)(87)(88)(89)(90)(91)(92)(93)(94)(95)(96)(97) View/request a protocol for this paper from Bio-protocol.…”

Accelerated Long-Term Hearing Loss Progression After Recovery From Idiopathic Sudden Sensorineural Hearing Loss

“…Recent studies have demonstrated the role of secreted factors in causing hearing loss in pathologies such as vestibular schwannoma, which can present with sudden SNHL and for which the audiometric hallmark is disproportionate loss in word recognition relative to threshold shift; undiagnosed Meniere's and autoimmune ear disease may also increase risk to bilateral hearing ( 27 , 30 , 31 ). While none of the patients in the current study were known to have other otologic disease at the time of initial evaluation for ISSHNL, sudden hearing loss can often serve as the initial presentation for an underlying inflammatory or autoimmune mechanism.…”

“…The analyses of hearing loss progression by isolated threshold and word recognition criteria could then be performed as secondary endpoints. As an isolated metric, a three-tone PTA was chosen for threshold analysis because this metric is most closely associated with speech reception thresholds and thus of highest clinical utility ( 25 – 27 ).…”

Current Understanding of Hearing Loss in Sporadic Vestibular Schwannomas: A Systematic Review

“…In most patients, the impairment is typically sensorineural in the ear ipsilateral to the tumor, and hearing deteriorates gradually ( 4 ). However, in some cases, hearing loss presents in the unaffected ear and worsens suddenly ( 5 , 6 ). In a recent retrospective study involving 661 SVS patients, the researchers noticed that there might exist a long-term risk of hearing loss in the contralateral ear ( 5 ).…”

“…However, in some cases, hearing loss presents in the unaffected ear and worsens suddenly ( 5 , 6 ). In a recent retrospective study involving 661 SVS patients, the researchers noticed that there might exist a long-term risk of hearing loss in the contralateral ear ( 5 ). After surgical and radiation therapy, hearing dysfunction is more prevalent.…”