Auditory brainstem and cochlear implants: functional results obtained after one year of rehabilitation.

Abstract

Very little information has been published on the clinical outcome of auditory brainstem implants (ABI). The present paper evaluates results obtained in a patient affected by a bilateral acoustic neuroma in type II neurofibromatosis who received an implant during removal of the residual tumor. One year later surgical revision of the ABI was necessary because no auditory sensation was obtained after ABI activation. Twelve months after the surgical revision, 12 electrodes out of 15 evoked auditory sensation. The results of rehabilitation were compared with those obtained in a group of eight postlingually deaf patients with cochlear implants (CI). Twelve months postoperatively the CI patients identified 97.7 +/- 5.1% of bisyllabic words in a closed set while the ABI patient identified 86%. CI patients recognized 87.1 +/- 11.3% of sentences and 81.3 +/- 14.8% of words with contextual cues while the ABI patient recognized 75% and 65% respectively. Speech recognition improved more slowly in the ABI patient than in the CI patients and his scores for open-set words and sentences without lip reading and contextual cues were poorer. Although the results obtained in the ABI patient were not as good as those obtained in the CI patients, the ABI patient said his quality of life was improved.