Cochlear Implant Outcomes in Children with Aplasia/Hypoplasia of the Cochleovestibular Nerve

Abstract

Objective: Cochlear implant (CI) candidates undergo a preoperative workup including radiologic, audiologic, and neurologic testing to determine if they are candidates for implantation. A percentage of these patients are found to have aplasia/hypoplasia of the cochleovestibular nerve (CVN). Past literature has debated if this population of children benefit from CI. Method: Retrospective review evaluating 17 children with radiographically diagnosed aplasia/hypoplasia of CVN. Eight of these children underwent cochlear implantation during the period from 2002 to 2009. The remaining 9 children were treated nonsurgically with hearing aids. Medical records, audiologic testing, imaging studies, and speech and language evaluations were reviewed. Results: Meaningful Auditory Integration Scale (MAIS) scores were available for 6 out of 8 CI patients. The average MAIS score pre-CI was 6.16. The average scores post-CI were 46.6, 72.8, 70.25, and 75. Auditory Preschool Language Scale (PLS-4) pre-CI was 4.75, and post-CI score was 23. The pre- and post-CI Expressive PLS-4 scores improved from 11.25 to 23.5. Phonetic inventory scores were 3.7 for vowel sounds and 3.17 for consonant sounds. Scores post-CI were 10.8 for vowel sounds and 12.5 for consonants. Linear regression analysis revealed a significantly faster acquisition of consonant sounds with the CI group. Conclusion: Children with CVN aplasia/hypoplasia who received a CI had improved audiologic and speech and language assessments post-CI. The CI group averaged higher scores in vowel and consonant sound production, which was statistically significant. Long term follow-up is needed to further evaluate outcomes of CI with CVN aplasia/hypoplasia.