[Auditory brainstem implant: indications and results].

OBJECTIVES

To summarize the indications and evaluate the Auditory Brainstem Implant (ABI) performances in neurofibromatosis type 2 (NF2) and other otologics indications, as postmeningitis ossified cochlea.

MATERIAL AND

METHODS

Main and first indication of ABI is NF2. Emergent indications are bilateral total ossified cochlea, vestibular schwannoma with controlateral lesions, cochlear nerve aplasia or inner ear's malformations. The pre-operative evaluation includes clinical, radiological, lipreading, and psychological status. A translabyrinthine or retrosigmoid approach is performed, depending on tumoral or not tumoral status. The auditory perception with the ABI is evaluated by testing, the words recognition in open-set lists, and the speech understanding with usual sentences.

RESULTS

In NF2 patients, best results are obtained in cases of smaller vestibular schwannoma and none, or short term, auditory deprivation. Negative prognostic factors are duration of total hearing loss (>10 years), tumor size (>30 mm), difficulties in electrode array placement, complications during post-operative course and number of active electrodes (<10). In cases of postmeningitis total deafness with totally ossified cochlea, results demonstrate a good benefit reaching these obtained with cochlear implant in post-meningitis deafness.

CONCLUSION

These results show a clear benefit of ABI in NF2 patients, with or without previous tumor removal, in case of small tumor with a short duration of hearing loss. In case of postmeningitis ossified cochlea, results potentially reach those of cochlear implants.