Vocabulary Development and Its Influencing Factors Among Cochlear Implanted Children With Cochlear Nerve Aplasia Diagnosed by MRI.

OBJECTIVES

To evaluate the expressive vocabulary ability of children with cochlear implants diagnosed with cochlear nerve aplasia (CN-A) and analyze potential factors influencing vocabulary development.

STUDY

DESIGN

Cross-sectional study.

SETTING

Tertiary referral center.

PARTICIPANTS

Thirty-one children diagnosed with CN-A by magnetic resonance imaging (MRI) who received a cochlear implantation (CI) before 3 years old.

INTERVENTIONS: Therapeutic-CI.

MAIN OUTCOME MEASURES: Expressive vocabulary was quantitatively assessed using the Early Vocabulary Inventory for Mandarin Chinese (EVI) after at least 3 years of CI usage. The cochleovestibular nerve diameter to facial nerve diameter ratio (CVN/FN ratio) was evaluated using preimplantation MRI. Preimplantation-aided pure tone average (PTA) was retrospectively reviewed. The relationship between the age of implantation, duration with CI, CVN/FN ratio, preimplantation-aided PTA, prosthetic configuration, and the expressive vocabulary size was analyzed.

RESULTS

The mean expressive vocabulary size was 283.60 (SD: 220.12; range: 0 to 628) for children with CN-A. Expressive vocabulary size was significantly correlated with the CVN/FN ratio, preimplantation PTA, and prosthetic configuration ( P s <0.05), whereas age at implantation and duration of CI were not significantly correlated ( P s >0.05). Hierarchical regression models showed that the CVN/FN ratio, preimplantation PTA, and prosthetic configuration independently contributed to predicting expressive vocabulary size ( P s <0.05).

CONCLUSION

Expressive vocabulary abilities are significantly impaired in children with CN-A. Preimplantation CVN size relative to the FN on MRI, residual hearing, and prosthetic configuration are important predictors of vocabulary development in this population.