Sequential Bilateral Cochlear Implantation in Children with Cochlear Nerve Deficiency

Objective: This study aimed to investigate the long-term auditory and speech outcomes of sequential bilateral cochlear implantation (BiCI) in children with cochlear nerve deficiency (CND). Methods: Sixteen CND children who underwent sequential BiCI were retrospectively reviewed. Auditory and speech abilities were evaluated using questionnaire-based rating scales, including the Categories of Auditory Performance (CAP), the Infant–Toddler Meaningful Auditory Integration Scale (IT-MAIS), and the Speech Intelligibility Rating (SIR). Closed-set and open-set speech recognition abilities were also measured. Results: The first cochlear implantation (CI) was performed at a median age of 12 months. The mean age at contralateral CI was 43 months, and the mean inter-implant interval time was 26 months. All patients showed continuous auditory and speech improvement over time. Of the sixteen patients, nine completed closed-set and/or open-set speech recognition assessments. After contralateral CI, all nine patients showed improved closed-set speech recognition scores. Four patients achieved closed-set test scores of more than 90% and open-set disyllable recognition scores ranging from 44 to 85%. In addition, two patients demonstrated better performance with bilateral CI than with unilateral CI. Conclusions: CND children showed favorable long-term auditory and speech outcomes after sequential BiCI, and some demonstrated bilateral benefit in speech perception. These findings suggest that BiCI may be a viable option for selected CND children.