Sequential Bilateral Cochlear Implantation in Children with Cochlear Nerve Deficiency

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).

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.

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.

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.