Is Transient Mixed Hearing Loss a Distinct Audiometric Feature in Patients With Inner Ear Schwannoma?

Area of Science:

• Neuro-otology
• Audiology
• Neurosurgery

Background:

• Inner ear schwannoma (IES) is a rare tumor affecting the auditory and vestibular pathways.
• Understanding the audiological manifestations of IES is crucial for early diagnosis and management.

Purpose of the Study:

• To characterize the evolving audiometric features in patients diagnosed with inner ear schwannoma (IES).
• To specifically investigate the occurrence and significance of transient mixed hearing loss in IES.

Main Methods:

• Retrospective analysis of audiological data from twelve patients with clinically diagnosed IES.
• Serial pure-tone audiometry, MRI scans, and additional audiological tests were performed.
• Audiogram configurations, hearing loss types, and air-bone gaps were analyzed in relation to tumor location.

Main Results:

• Initial audiograms showed U-shaped (41.7%) or rising (33.3%) configurations.
• Transient mixed hearing loss with air-bone gaps occurred in 75.0% of patients, predominantly in low-to-mid frequencies.
• All patients experienced progressive hearing loss, with 91.7% developing severe-to-profound hearing impairment.

Conclusions:

• Early audiometric findings in IES include sensorineural hearing loss with U-shaped/rising configurations and low-to-mid frequency air-bone gaps.
• Rapidly progressive hearing deterioration is a common feature.
• Transient mixed hearing loss is identified as a distinctive audiometric characteristic of inner ear schwannoma.