Abstract
Vestibular schwannoma (VS) is a non-malignant intracranial neoplasm arising from the vestibular branch of the 8th cranial nerve; sensorineural hearing loss (SNHL) is the most common associated symptom. Understanding whether VS imaging characteristics at the time of VS diagnosis can be associated with severity of VS-induced SNHL can impact patient counseling and define promising areas for future research. Patients diagnosed with VS at Massachusetts Eye and Ear (MEE) from 1994 through 2018 were analyzed if magnetic resonance imaging at VS presentation and sequential audiometry were available. Results were compared with original studies available in PubMed, written in English, on VS imaging characteristics and their impact on hearing in patients. A total of 477 patients with unilateral VS from the MEE database demonstrated no significant correlation between any features of tumor imaging at the time of VS diagnosis, such as VS size, impaction or location, and any hearing loss metric. Twenty-three published studies on the impact of VS imaging characteristics on patient hearing met inclusion criteria, with six solely involving NF2 patients and three including both sporadic and NF2-related VS patients. Fifteen studies reported a significant relationship between SNHL and at least one VS imaging characteristic; however, these trends were universally limited to NF2 patients or involved small patient populations, and were not reproduced in larger studies. Taken together, SNHL in sporadic VS patients is not readily associated solely with any tumor imaging characteristics. This finding motivates future studies to define how VS microenvironment and secreted molecules influence VS-induced SNHL.
Highlights
Vestibular schwannoma (VS) is the most common solitary, intracranial schwannoma, typically arising from Schwann cells of the vestibular branch of cranial nerve VIII
Our database for sporadic VS patients augments the literature by providing the largest patient population to date in which reinterpretation of the primary data was feasible [16]
Analyzing by an exhaustive range of tumor size factors including maximal linear dimension, cross-sectional area, total volume, impaction, and Koos classification all yielded no correlation with hearing loss at the time of VS diagnosis
Summary
Vestibular schwannoma (VS) is the most common solitary, intracranial schwannoma, typically arising from Schwann cells of the vestibular branch of cranial nerve VIII. Small VSs arguably pose the most complex determination of management, given their associated symptoms and size not warranting immediate intervention as clearly as for larger, compressive tumors. Utilizing high-resolution MRI protocols, protein deposition in the cochlea and labyrinthine hypo-intensity have been investigated as contributing factors to VS-associated hearing loss [9, 10]. Further studies steer their focus towards the physical location of tumors, such as the superior vestibular nerve (SVN), and overall tumor size [11–14]. The majority of such studies remain limited by small sample size, despite the availability and inclusion of strong audiometric and imaging data. Studies with larger populations struggle with inconsistent or incomplete MRI data [11, 15]
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have