The impact of cochlear implantation on speech and language outcomes in children with asymmetric sensorineural hearing loss

Abstract

Introduction: Cochlear implantation (CI) is considered in children with asymmetric sensorineural hearing loss (ASHL), or severe to profound sensorineural hearing loss in one ear, and better hearing contralaterally. The benefits of a CI in these children are not well established. This study investigated the impact of unilateral CI on speech and language outcomes in pediatric patients with ASHL.

Methods: The retrospective chart review identified pediatric patients who underwent cochlear implantation for ASHL at a tertiary single center institution between 2014 and 2017. Children who underwent cochlear implantation in the poorer ear and maintained a hearing aid in the better ear were included, while children with cognitive impairment or prior cochlear nerve deficiency and auditory neuropathy were excluded. Speech and language measures were evaluated prior to implantation and at regular six-month intervals postoperatively. Ear specific Audiometry was evaluated at every visit and varied developmentally appropriate speech recognition tasks, including questionnaires, closed-set, and open-set measures, accounted for advancing childhood milestones. Specific measures of speech articulation, expressive and receptive language, and vocabulary were assessed including: Goldman Fristoe Test of Articulation (GFTA-3), Clinical Evaluation of Language Fundamentals (CELF-P2 or CELF-5), Receptive One-Word Picture Vocabulary Test (ROWPVT) and Expressive One Word Picture Vocabulary Test (EOWPVT). The mean difference and standard deviation of speech and language outcomes at preoperative and postoperative evaluations were calculated. The change in outcomes were further assessed over each post-operative time point.

Results: Twenty-six children with asymmetric sensorineural hearing loss were included in the analysis, with 11 (42%) having bilateral enlarged vestibular aqueducts (EVA). At time of CI, unaided mean Pure Tone Average (PTA-4) for the better ear was 62Db HL, and worse ear was 92Db HL. There was an improvement in speech recognition in the implanted ear as expected. All preoperative speech and language evaluations were conducted within 7 months of cochlear implantation. Twenty-three patients had at least 1 postoperative re-evaluation. Fourteen children had preoperative and postoperative assessments with the same tool, with 13 patients (93%) showing improvement in at least 1 domain. For patients with repeated assessment within 12 months of surgery, we observed an average improvement in standard scores of: GFTA-3 (+11.2), CELF-P2 Core Language (+10.3), CELF-5 Core Language (+7.0), ROWPVT (+2.8) and EOWPVT (+4.5). Individual results are described.

Conclusion: Improvement in speech and language measures can be demonstrated in children undergoing unilateral cochlear implantation for asymmetric sensorineural hearing losses. These children, who are not typical CI candidates, can benefit from a CI in the poorer ear.

Keywords: Asymmetric sensorineural hearing loss; Cochlear implantation.