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Updated: Jun 11, 2026
Cochlear Implant Surgery and Electrically-evoked Auditory Brainstem Response Recordings in C57BL/6 Mice
Published on: January 9, 2019
Cochlear Nerve Responsiveness to Electrical Stimulation in Late-Implanted Prelingually Deafened Adults
Xiuhua Chao1,2, Xianqi Liu1,2, Jianfen Luo1,2
1Department of Otolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Shandong University, Jinan, People's Republic of China.
Objectives:
To evaluate cochlear nerve responsiveness to electrical stimulation in prelingually deafened adults with late cochlear implantation by analyzing electrically evoked compound action potentials (eCAPs), and to compare their neural status with that of postlingually deafened adults.
Design:
Participants were divided into two groups: prelingually deafened adults (Prelingual) group (n = 15) and postlingually deafened adults (Postlingual) group (n = 11). All participants used Cochlear Nucleus cochlear implants. The input/output function of the eCAP under inter-phase gap (IPG) conditions of 7 and 35 µsec, and refractory recovery functions under the 7 µsec IPG condition, were recorded at basal, middle, and apical electrodes for each participant. Dependent variables included eCAP input/output function slope, maximum amplitude, threshold, N1 latency, IPG effect on these measurements, absolute refractory period (t0), and relative refractory recovery time (τ). A linear mixed-effects model was used to analyze the effects of groups, electrode locations, and IPGs on these dependent variables.
Results:
Prelingually deafened adults exhibited significantly shallower eCAP input/output function slopes compared with postlingually deafened adults, while the maximum amplitudes, thresholds, and N1 latencies did not differ significantly between groups. For IPG effects, the Postlingual group demonstrated significantly larger IPG-induced increases in maximum amplitude than the Prelingual group, whereas IPG effects on slope and N1 latency did not differ between groups. The t0 and τ were comparable across groups. Electrode-specific analyses revealed reduced eCAP amplitudes and shallower slopes at basal electrodes compared with middle or apical electrodes in the postlingual group, whereas these electrode-related differences in amplitude and slope were not significant in the Prelingual group.
Conclusions:
Despite prolonged auditory deprivation, prelingually deafened adults generally retain substantial cochlear nerve function, although neural recruitment appears reduced. This preserved cochlear nerve function is crucial for processing electrical stimulation signals.
