Cochlear Implants vs Hearing Aids in Auditory Neuropathy

Abstract

Objective: Patients with auditory neuropathy spectrum disorder (ANSD) exhibit altered neural synchrony in response to auditory stimuli. Cochlear implantation (CI) is thought to improve neural synchrony in response to auditory stimuli and improve speech perception relative to conventional hearing amplification (HA). Method: Retrospective review was performed of 40 patients with ANSD treated at Vanderbilt University in 1999-2011. Twenty-two patients underwent CI, 11 received HA only, and 7 were observed. Pretreatment performance was assessed through parent questionnaire (IT-MAIS) and speech/language evaluation. Posttreatment outcomes were assessed using IT-MAIS and closed/open-set speech perception scores. Results: Average follow-up for all patients was 36 months (range 0-90). Two of 7 observed patients exhibited neuromaturation over time. Median available pretreatment IT-MAIS scores were 13 and 34 for CI and HA groups, respectively (difference NS, rank sum test, P = .06). All CI patients had a prior HA trial with failure of auditory skills development. Posttreatment, 15/20 CI patients and 5/11 HA patients with available data achieved closed/open-set speech perception scores ≥60%. No differences between groups were found in post-treatment IT-MAIS scores (rank sum test, P = .69) or the percentage of patients achieving the above levels of closed/open-set speech perception (Fisher’s exact test, P = .13). Conclusion: In our ANSD population, patients undergoing CI achieved at least comparable and possibly improved overall speech perception outcomes relative to HAs despite a greater initial level of auditory impairment as assessed by parent questionnaire. These findings further validate use of CIs in ANSD patients with failure of auditory skills development.