Impact of early cochlear implantation on the linguistic development of the deaf child.

Objective: The purpose of this study was to examine prognostic factors of cochlear implantation and to evaluate the impact of early implantation on linguistic development in deaf children.
Study Design: Retrospective study.
Setting: Tertiary referral center.
Patients: Seventy-four prelingually deafened children implanted before the age of 5 years.
Intervention: Annual follow-up after cochlear implantation.
Main Outcome Measures: Speech perception, intelligibility, and expressive and receptive language scores from age 3 to 8 years were globally compared between 4 subgroups of children. Significant differences were further explored by intergroup comparisons. Stepwise logistic linear regression was performed using the following variables: age at implantation, duration of cochlear implant (CI) use, preoperative hearing levels, age of hearing aid (HA) fitting, and age at time of the evaluation. Preoperative data were not available.
Results: Between group comparisons displayed significant differences according to age at implantation. Multivariate analysis demonstrated the positive impact of early implantation on receptive language. Moreover, duration of CI use and preoperative hearing levels were statistically correlated with performance on speech perception, intelligibility, and expressive and receptive language. Age of HA fitting was associated with speech intelligibility.
Conclusion: Age at implantation, duration of CI, preoperative hearing levels, and age of HA fitting may each be useful in predicting linguistic success after cochlear implantation. Other factors such as preoperative linguistic development may also influence postoperative outcomes, but the lack of tests suitable for use with very young children makes such a hypothesis difficult to confirm.