Sex-Specific Enlarged Vestibular Aqueduct Morphology and Audiometry

American Journal of Otolaryngology
14 Jun, 2019 ,

This retrospective, longitudinal, and repeated-measures study assess vestibular aqueduct (VA)  morphology and frequency-specific hearing thresholds with sex as the primary predictor of interest. Females seem to have greater enlargement of the vestibular aqueduct, this difference does not extend to hearing loss. Therefore, study results indicate that criteria for enlargement of the vestibular aqueduct (EVA)  diagnoses may benefit from re-evaluation. 

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Abstract

Objective

Enlargement of the vestibular aqueduct (EVA) is one of the most common congenital malformations in pediatric patients presenting with sensorineural or mixed hearing loss. The relationship between vestibular aqueduct (VA) morphology and hearing loss across sex is not well characterized. This study assesses VA morphology and frequency-specific hearing thresholds with sex as the primary predictor of interest.

Materials and methods

A retrospective, longitudinal, and repeated-measures study was used. 47 patients at an academic tertiary care center with hearing loss and a record of CT scan of the internal auditory canal were candidates and included upon meeting EVA criteria after confirmatory measurements of vestibular aqueduct midpoint and operculum widths. Audiometric measures included pure-tone average and frequency-specific thresholds.

Results

Of the 47 patients (23 female and 24 male), 79 total ears were affected by EVA; the median age at diagnosis was 6.60 years. After comparing morphological measurements between sexes, ears from female patients were observed to have a greater average operculum width (3.25 vs. 2.70 mm for males, p = 0.006) and a greater average VA midpoint width (2.80 vs. 1.90 mm for males, p = 0.004). After adjusting for morphology, male patients' ears had pure-tone average thresholds 17.6 dB greater than female patients' ears (95% CI, 3.8 to 31.3 dB).

Conclusions

Though females seem to have greater enlargement of the vestibular aqueduct, this difference does not extend to hearing loss. Therefore, our results indicate that the criteria for EVA diagnoses may benefit from re-evaluation. Further exploration into morphological and audiometric discrepancies across sex may help inform both clinician and patient expectations.