Cochlear implantation is a common treatment approach for children with auditory neuropathy/dyssynchrony (AN/AD) who do not benefit from hearing aids. The auditory brainstem response (ABR) is a measure of neural synchrony along the auditory pathway up through the brainstem. By definition, acoustically evoked ABR is absent in AN/AD, however, ABR can be elicited by electrical stimulation through the cochlear implant (electrically evoked ABR [EABR]). Reports of EABR with AN/AD to date have been primarily descriptive in nature. The objective of this study was to quantify EABR wave V measures in implanted children with and without AN/AD.
Retrospective analysis of EABR waveforms from March 2000 through February 2005.
Comprehensive Cochlear Implant Program/Tertiary Referral Center.
Pediatric cochlear implant users of two etiologic groups: congenital AN/AD (n = 5) and other congenital profound sensorineural hearing loss (n = 27).
Intraoperative EABR wave V threshold, suprathreshold amplitude, and latency measures were compared between groups.
The EABR threshold and suprathreshold amplitude measures across the population were variable regardless of etiology. With some exceptions, a trend was observed for the AN/AD group that included average or below-average thresholds and below-average suprathreshold response amplitudes.
Cochlear implantation can provide synchronous neural responses to auditory stimulation in AN/AD, as previously known. The quantification of EABR measures in this study indicates that subjects with AN/AD have sufficient neural sensitivity to electrical stimulation, however, they may experience less robust neural responses at suprathreshold levels. Given the heterogeneity of potential causes of AN/AD, however, caution needs to be applied when grouping this population for analyses.
Department of Otolaryngology and Communication Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, U.S.A.
Address correspondence and reprint requests to Christina L. Runge-Samuelson, Ph.D., Department of Otolaryngology, Medical College of Wisconsin, 9200 W. Wisconsin Ave., Milwaukee, WI 53226; E-mail: email@example.com
This study was supported by the Medical College of Wisconsin Department of Otolaryngology and Communication Sciences Toohill Research Fund.