Auditory outcomes after cochlear implantation in children with additional disabilities: A grading-based evaluation of inner ear malformations

Abstract

Objective: This study aimed to evaluate auditory and speech outcomes after cochlear implantation (CI) in children with additional disabilities (ADs), including autism spectrum disorder (ASD), with a particular focus on the impact of inner ear malformation (IEM) grading based on modiolus and cochlear nerve integrity. Methods: We retrospectively reviewed 58 children with bilateral severe-to-profound sensorineural hearing loss and at least one AD who underwent CI between 2007 and 2022 at a national cochlear implant center. ADs included ASD, intellectual disability (ID), and attention-deficit/hyperactivity disorder (ADHD). IEMs were classified into Grades 0–III based on radiological evaluation. Auditory outcomes were assessed using the Revised Categories of Auditory Performance (R-CAP) and Speech Intelligibility Rating (SIR) scales. Statistical analyses included non-parametric tests and multivariable logistic regression. Results: Among the 58 children, 60 % had ASD and 83 % had ID. IEMs of Grade II or higher were observed in 26 %. Median age at implantation was 29.5 months, and median age at evaluation was 86.5 months. R-CAP scores were significantly higher in children with Grade 0– I IEM than in those with Grade ≥ II (median 8 vs. 2, p < 0.01). R-CAP ≥8, indicating conversational speech understanding, was achieved by 60 % of Grade 0– I cases but only 13 % of those with more severe IEMs. Multivariable analysis showed that mild ID and severe IEMs were independent negative predictors of achieving R-CAP ≥8, while age at assessment was positively associated with better outcomes. Conclusion: CI can provide meaningful auditory development for children with ADs, but outcomes vary by cognitive and anatomical factors. Early implantation remains essential despite challenges in diagnosing conditions like ASD before surgery, supporting the need for ongoing developmental surveillance and individualized habilitation planning.