Author(s)
Robert J. Macielak, BS
Jameson K. Mattingly, MD
Ursula M. Findlen, PhD
Oliver F. Adunka, MD
Affiliation(s)
Ohio State University College of Medicine
Abstract:
Educational Objective: At the conclusion of this presentation, the participants should be able to explain that the true prevalence of bilateral hearing loss in children with unilateral enlarged vestibular aqueduct may be lower than previously reported in the literature. Objectives: To evaluate the prevalence of bilateral hearing loss in children with unilateral enlarged vestibular aqueduct (EVA) at a single institution. Study Design: A retrospective case review conducted at a tertiary care pediatric referral center. Methods: Electronic medical record review was performed to identify children with radiologic findings of unilateral EVA and normal labyrinthine anatomy of the contralateral ear diagnosed via high resolution CT and/or MRI. Audiologic data including PTA, type of hearing loss, and followup time period were also recorded. Results: Fifty-nine patients with unilateral EVA and normal contralateral inner ear anatomy were identified. Thirty-eight patients were diagnosed via CT, 15 patients were diagnosed via MRI, and 6 patients were diagnosed via both imaging modalities. Three (5.1%) patients were noted to have bilateral hearing loss with a PTA of 33.3 dB HL in the better hearing ear while 56 patients (94.9%) were diagnosed with unilateral hearing loss with a PTA of 10.0 dB HL in the better hearing ear. On average, patients were followed audiologically for 48 months. Conclusions: The true prevalence of bilateral hearing loss in children with unilateral EVA may be lower than previously reported in the literature. Observed differences could stem from inaccuracies in utilizing CT morphologic and radiographic parameters to diagnose EVA cases. Further, MRI appears more definitive in identifying the fluid signal in the endolymphatic sac to determine enlargement as compared to morphometric analysis. Further studies incorporating strict diagnostic and imaging criteria could more definitively elucidate the prevalence of this clinical finding.