Auditory Outcome of Cochlear Implantation in Adolescent and Adult Patients with Enlarged Vestibular Aqueduct and Biallelic SLC26A4 Mutations / 대한이비인후과학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: Mutations of the SLC26A4 gene cause congenital hearing loss and enlarged vestibular aqueduct (EVA). A considerable proportion of patients with SLC26A4 mutations have significant residual hearing at birth that eventually worsen and become the cause for cochlear implantation (CI) later in their adolescence or adulthood. We analyzed the auditory outcome and prognostic factors of CI in patients with EVA and biallelic SLC26A4 mutations showing progressive early-onset hearing loss, who eventually had implantation in their adolescent or adult periods. SUBJECTS AND METHOD: Sixteen patients with EVA carrying biallelic SLC26A4 mutations who received CI after 12 years of age were included for analysis. The outcome and prognostic factors of CI were analyzed. The postoperative follow-up period ranged from 3 to 48 months. RESULTS: The age at CI ranged from 12 to 44 years. The categories of auditory performance score was significantly improved after CI from 3.1 to 4.9 (p < 0.05). The mean sentence scores improved significantly in the auditory-visual and auditory-only conditions (p < 0.05). The significant prognostic factors were measurable bone conduction thresholds, preoperative residual hearing, recent history of sudden aggravation of hearing loss, and preoperative speech intelligibility rating scores. There was a tendency of lower postoperative sentence scores in the group with homozygous H723R mutation, but statistical significance was not reached. CONCLUSION: Despite the early-onset of hearing loss, significant improvement in auditory performance can be expected after CI in adolescent and adult patients with EVA and biallelic SLC26A4 mutations. Significant prognostic factors should be considered in selecting candidates and preoperative counseling for CI.