Asymmetric Hearing Loss Prompting MRI Referral in a Military Population: Redefining Audiometric Criteria. (April 2018)

• Record Type: Journal Article
• Authors: Tolisano, Anthony M.; Burgos, Ricardo M.; Lustik, Michael B.; Mitchell, Lex A.; Littlefield, Philip D.
• Is Part Of: Otolaryngology--head and neck surgery. Volume 158:Number 4(2018)
• Page Start: 695
• Page End: 701
• Publication Date: 2018-04
• Subjects: asymmetric hearing loss -- retrocochlear tumor -- magnetic resonance imaging -- sensitivity -- specificity; Head -- Surgery -- Periodicals; Neck -- Surgery -- Periodicals; Otolaryngology -- Periodicals; 617.51
• DOI: 10.1177/0194599818756300
• Languages: English
• ISSNs: 0194-5998

Abstract

Objective: To reevaluate asymmetric sensorineural hearing loss (ASNHL) criteria used to justify magnetic resonance imaging (MRI) in the evaluation of retrocochlear tumors in a military population. Study Design: Retrospective case-control study. Setting: Tertiary care military medical center. Subjects and Methods: Patients with military service and a history of ASNHL prompting referral for MRI, with or without retrocochlear tumors, were compared between 2005 and 2016. Predictor variables included pure tone ASNHL, speech audiometry, and a history of noise exposure. Logistic regression models for hearing asymmetries were performed, and receiver operator curves were used to calculate sensitivity and specificity. Results: Thirty-eight retrocochlear tumors were identified. The MRI diagnosis rate for patients with ASHNL was 0.85%. Patients with tumors were slightly older (42 vs 37 years, P = .021) and had less noise exposure (47% vs 85%, P < .001). A sensitivity of 0.83 and a specificity of 0.58 were calculated for asymmetries ≥10 dB at 2000 Hz without adjusting for noise exposure. Instituting this imaging threshold would have reduced the number of MRI scans by half while missing 16% of tumors. Conclusion: The tumor diagnosis rate among those undergoing MRI for ASNHL is low in the military population, likely because service-related noise exposure commonly causes ASNHL. Optimal MRI referral criteria should conserve resources while balancing the risks of over- and underdiagnosis. For those with a history of military service, an asymmetry ≥10 dB at 2000 Hz among patients meeting current ANSHL referral criteria is most predictive of a retrocochlear tumor.