Symptoms, Audiometric and Vestibular Laboratory Findings, and Imaging in a Concurrent Superior Canal Dehiscence Syndrome and Vestibular Schwannoma: A Case Report

BACKGROUND: Dizziness is a common complaint that can arise from multiple systems in the body. Objective vestibular tests are used to understand the underlying function of the vestibular system and whether or not it may be contributing to the dizziness symptoms experienced by the patient. Even when comprehensive case history is consistent with an otologic etiology, audiometric and vestibular tests are ordered to objectively characterize inner ear function to help further refine the differential diagnoses and aid in guiding treatment options. Few reports in the literature describe audiometric and vestibular results in patients with multiple concurrent otologic etiologies. PURPOSE: This case provides a description of audiometric, vestibular, and imaging results in a case of concurrent bilateral superior canal dehiscence, right-sided vestibular schwannoma, and right-sided posterior canal benign paroxysmal positional vertigo. The patient's symptoms and laboratory findings are described in detail and, where appropriate, highlight challenges that may arise in interpretation. RESEARCH DESIGN: A case report. RESULTS: The patient presented for evaluation of dizziness, asymmetric hearing loss, and autophony. Comprehensive audiometric evaluation shows asymmetric sensorineural hearing loss and an air-bone gap at 250 Hz in the right ear. Vestibular evaluation shows right caloric asymmetry along with abnormal cervical vestibular- and ocular vestibular-evoked myogenic potentials, with the left ear showing results consistent with the third-window pathology. CONCLUSIONS: Comprehensive assessment of symptoms and critical thinking while performing testing are necessary when examining multiple concurrent otologic etiologies in a patient. Knowledge of anticipated test results and physiology may help the audiologist to synthesize results and make appropriate clinical recommendations as part of the multidisciplinary team.