Long-term follow-up of hearing loss in children and young adults with enlarged vestibular aqueducts: relationship to radiologic findings and Pendred syndrome diagnosis.

OBJECTIVE: To describe the long-term audiologic findings in pediatric patients with enlarged vestibular aqueducts (EVAs). The relationship between the hearing loss (HL) and the dimensions of the EVA, enlarged endolymphatic duct (EED), or enlarged endolymphatic sac (EES) was also investigated. The influence of a Pendred syndrome (PS) diagnosis on the audiologic phenotype was also examined. STUDY
DESIGN: Retrospective analysis of case notes and imaging records, including measurement of the dimensions of the EVA, EED, and EES.
SETTING: Tertiary referral center. PATIENTS: Twenty-seven patients (21 female, 6 male) had an EVA in at least one ear. Eighty-five percent had bilateral enlargements. Median age at onset of follow-up was 5.0 years, and median follow-up was 9.7 years. MAIN OUTCOME MEASURES: Hearing thresholds at the start and end of follow-up, rate of progression of HL, history of sudden drops in hearing.
RESULTS: : All ears with an EVA had HL. Average HL at the start and end of follow-up was severe. Thirty-seven percent of patients had progressive HL, and 33% reported sudden drops in hearing. Progression was significantly associated with a history of sudden drops. PS patients had worse hearing at the end of follow-up as compared with nonsyndromic patients. There was no evidence of a relationship between the dimensions of the EVA, EED, or EES and the severity or progression of HL.
CONCLUSIONS: Patients with EVAs should be advised to avoid known trigger factors for sudden drops in hearing (e.g., minor head trauma). A diagnosis of PS may be associated with a worse audiologic prognosis.