Hearing in static unilateral vestibular schwannoma declines more than in the contralateral ear

To determine the effect of static vestibular schwannomas on hearing.

Retrospective review of audiometric measures in 15 patients with documented nongrowth of internal auditory canal and cerebellopontine angle enhancing masses.

Data from patients seen in an ambulatory tertiary care setting between the years of 2002 and 2012 with a diagnosis of acoustic neuroma or vestibular schwannoma were reviewed. Exclusion criteria included preexisting otologic disease, prior therapy for the schwannoma, and tumor growth. Radiology reports were reviewed to ensure nongrowth and were confirmed by taking magnetic resonance imaging (MRI) measurements ourselves. Audiologic measurements included pure tone average, enhanced pure tone average (average of .5, 1, 2, and 4 KHz thresholds), 4 KHz threshold, 8 KHz threshold, and speech discrimination. The data were analyzed using mixed effect model with unstructured variance-covariance structure.

Difference in audiometric measures between ears significantly (P<.05) increased for all measures except 8 KHz.

Spontaneous decline in hearing relative to time is exaggerated in the affected ear despite no vestibular schwannoma growth. This finding can be useful for patient counseling and treatment decision making.