Hearing rehabilitation in neurofibromatosis type 2 patients: cochlear versus auditory brainstem implantation

We aimed to evaluate and compare the auditory performance of neurofibromatosis type 2 (NF2) patients with bilateral total deafness fitted with cochlear or auditory brainstem implants.

A retrospective case review was performed. Nine patients suffering from NF2 who underwent hearing rehabilitation by means of cochlear (4 patients) or auditory brainstem (5 patients) implantation participated in the study. Postoperative auditory performance was assessed using closed- and open-set tests.

In the group of patients fitted with a cochlear implant, 3 subjects achieved open-set speech recognition abilities comparable to those of standard adult postlingual implant patients; the remaining patient scored 0% in all open-set format tests, reporting benefits only in environmental sound detection and lip-reading. Among the 5 patients who underwent auditory brainstem implantation, 1 reached good open-set speech recognition skills, scoring 70% in the common phrases comprehension test, and she was able to communicate on the telephone. Two other patients achieved open-set speech understanding (respectively, 33 and 41% in the common phrases comprehension test), reporting daily use of their device. The remaining 2 patients did not achieve any level of open-set speech perception, obtaining only improved access to environmental sound and lip-reading skills.

Our study confirmed literature data reporting that cochlear implantation may offer open-set speech communication in NF2 patients. In this small cohort, cochlear implant patients performed better than auditory brainstem implant patients, even if variability in auditory performance was observed with both devices. More studies are needed in order to clarify the role and reliability of electrophysiological tests in predicting the residual functionality of the cochlear nerve after tumor removal.