Cochlear implantation at under 12 months: report on 10 patients.

OBJECTIVES

There is growing evidence that early application of a cochlear implant in children affected by profound congenital hearing loss is of paramount importance for the development of an adequate auditory performance and language skills. For these reasons and as a result of advances in audiologic diagnosis and an enhanced awareness of the safety of cochlear implants, the age of implantation has substantially decreased over recent years. Children aged as little as 12 months are now being implanted in some centers. On the basis of our experience with very young children, we believe that the date of implantation may be further reduced to only 4 to 6 months of age.

STUDY DESIGN

Over the period from November 1998 to April 2004, 103 children have been fitted with cochlear implants and 11 with auditory brainstem implants in our department, including 65 children aged below 3 years. The present study focuses on 10 children aged less than 12 months fitted with cochlear implants from November 1998 to December 2003.

METHODS

The children's ages ranged from 4 to 11 (mean 9.5) months. Five were males and five females. All received a Nucleus CI 24 M. Postoperative auditory performance, as evaluated at the latest follow-up, was based on the category of auditory performance (CAP). The results obtained in these 10 children were compared with those obtained with cochlear implants in children belonging to older age brackets. The criteria used to assess speech performance were onset of babbling onset and babbling spurt, and the results observed were compared with those of a control group of 10 normally hearing children.

RESULTS

Surgery was uneventful, and no immediate or delayed complications were encountered. Auditory performance was seen to increase as function of early age of implantation and length of implant use. All 10 children had a CAP score of 3 within 6 months of cochlear implant activation. The onset of babbling occurred very early (i.e., within 1 to 3 months of activation of the implant in all 10 patients), regardless of age at implantation, whereas the babbling spurt was recorded at times ranging from 3 to 5 months after implant activation. The positive impact of early implantation on babbling was clearly shown by the fact that the earlier the activation of the cochlear implant, the closer the results were to the outcomes of normally hearing children.

CONCLUSIONS

We encourage very early implantation to facilitate a series of developmental processes occurring in the critical period of initial language acquisition. The indices we used in the present study (i.e., CAP and babbling) suggest that early cochlear implantation tends to yield normalization of audio-phonologic parameters, which enables us to consider the performance of children implanted very early as being similar to that of their normally hearing peers.