Auditory neuropathy and cochlear implantation

Abstract

This work was undertaken to study the prevalence of auditory neuropathy among deaf subjects “as diagnosed by objective tests for peripheral neuropathy” together with their performance using the cochlear implant (CI) device. Thirty-five adult CI subjects versus twenty subjects with sensorineural hearing loss of both genders and of variable etiology of hearing loss were included. Electrophysiological testing of peripheral nerves in the form of nerve conduction studies (NCS) and electromyography (EMG) were performed on all subjects of both groups. For the CI subjects, the post-operative performance was estimated using Arabic speech perception tests. Results showed a good percentage of CI subjects had mild polyneuropathy of the demyelinating type. Those subjects were categorized as possible auditory neuropathy (AN). Post-operative Arabic speech tests of both the possible AN and normal NCS groups were comparable. This work addressed issues related to the possible site of lesion in AN and the role of electrical stimulation in these cases. In conclusion, cochlear implantation is harder in mild cases of neuropathy particularly in children.