Cochlear implantation versus hearing amplification in patients with auditory neuropathy spectrum disorder

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). Study Design. Retrospective review. Setting. Tertiary otologic practice. Subjects and Methods. Subjects included patients with ANSD treated at Vanderbilt University from 1999 to 2011. Sixteen patients underwent CI, and 10 received binaural HAs. Pretreatment performance was assessed through speech reception thresholds and parent questionnaire (Infant-Toddler Meaningful Auditory Integration Scale [IT-MAIS]). Posttreatment outcomes were assessed using IT-MAIS and closed-/open-set speech perception scores. Results. Two HA users underwent neuromaturation and were excluded from further analysis. For the remaining patients, median duration of device use was 48 months. All CI patients had a prior binaural HA trial with failure of auditory skills development. Median available pretreatment IT-MAIS score was 13 and 30 for CI and HA groups, respectively (rank sum test, P = .32). Posttreatment, 6 of 16 CI patients and 4 of 8 HA patients achieved open-set speech perception scores 60%. No differences between groups were found in posttreatment IT-MAIS scores (rank sum test, P = .11) or the percentage of patients achieving the above levels of open-set speech perception (Fisher exact test, P = .67). Conclusions. A wide range of speech perception outcomes are observed in ANSD patients. In our ANSD population, patients who exhibited failure of auditory skills development with HAs were able to achieve comparable overall speech perception outcomes after CI relative to those who continued to make appropriate auditory progress with HAs alone.