Abnormal CT findings are risk factors for otitis media-related sensorineural hearing loss

Inflammatory processes in chronic otitis media (COM) can damage the inner ear, resulting in sensorineural hearing loss (SNHL). The purpose of this study was to evaluate risk factors by computed tomography (CT) findings for COM-related SNHL in patients with unilateral COM.

Records from January 2009 to December 2012 of 231 patients with unilateral COM and a normal contralateral ear were retrospectively evaluated. Bone conduction thresholds were calculated for each ear at 0.5, 1, 2, and 4 kHz. If bone conduction threshold averaged across the four frequencies of the COM ear was 10 dB greater than that of the contralateral ear, the patient was classified under the SNHL group. Temporal bone CT images were analyzed to determine the presence or absence of soft tissue density in the attic (medial/lateral), antrum, oval window niche, and round window niche. Multivariate analysis of sex, age (< 50 years; ≥ 50 years), disease duration (< 20 years; ≥ 20 years), perforation size (small; moderate; large) and the presence of soft tissue density in the attic (medial/lateral), antrum, oval window niche, and round window niche was used to determine the factors related to COM-related SNHL.

Of the 231 patients, there were 51 patients (22.1%) in the SNHL group and 180 patients (77.9%) in the non-SNHL group. Multivariate analyses showed that the presence of soft tissue density in the antrum (odds ratio [OR] 3.80; 95% confidence interval [CI] 1.74-8.32; p = 0.001), age ≥ 50 years and more (OR 3.32; 95% CI 1.62-6.81; p = 0.001), disease duration ≥ 20 years (OR 2.80; 95% CI 1.31-6.02; p = 0.008), and the presence of soft tissue density in the round window niche (OR 2.42; 95% CI 1.12-5.21; p = 0.024) were independently related to COM-related SNHL.

COM-related SNHL was present in 22% of ears with COM. The presence of soft tissue density in the antrum, determined from temporal bone CT, increased the OR of SNHL to 3.8. Age, disease duration, and the presence of soft tissue density in the round window niche were also independent predicting factors for SNHL. These findings may be used as informative references for patients with COM.