Cochlear Implants and Auditory NeuropathySpectrum Disorder

Objective: The results of cochlear implantation in patients that present with auditory neuropathy spectrum disorder (ANSD) patients have been variably reported. The effectiveness of the treatment modality varies in such patients. Hearing rehabilitation in this group of patients has been very challenging. Considerable controversy exists whether to provide conventional amplification (hearing aids or personal FM systems) or cochlear implants (CI) to children with ANSD. With this background, we present our experience with select subset of ANSD cases that derived benefit from cochlear implant. Methodology: We studied and evaluated all the paediatric cases (i.e. less than 12 years of age) using audiological test battery. The cases with other co-morbidities, abnormality of auditory nerve and cochlea were excluded. Diagnosed cases of ANSD were given bilateral, behind the ear, digital hearing aids as per their behavioural responses for 6 months and enrolled for communication development in the auditory verbal habilitation program. They were evaluated for auditory perception using Category of Auditory Performance scoring system. The ANSD cases that derived “intermediate benefit” as per our criteria at 6 months post hearing aids were taken up for unilateral cochlear implant. All the implanted ANSD cases continued in auditory verbal habilitation program of our hospital and their progress on auditory perception post cochlear implant was monitored using CAP scoring system. Results: A total of 1313 cases were evaluated for hearing loss. Out of these 65 cases were detected to have ANSD (42 bilateral and 23 unilateral ANSD).Unilateral ANSD cases were excluded from the study. Hearing aids were fitted in all the bilateral ANSD cases. After 6 months of hearing aid fitting thirteen ANSD cases showed “intermediate benefit” and were taken up for cochlear implant. After 6 months of implant usage all ANSD cases showed “good” progress on CAP. Conclusion: Hearing aid trial should be given to all the cases diagnosed with ANSD and those who derive “intermediate benefit” from hearing aids and AVT should be considered for cochlear implant.