Eur Arch Otorhinolaryngol. 2026 Jul 19. doi: 10.1007/s00405-026-10449-9. Online ahead of print.
ABSTRACT
PURPOSE: Electrically evoked compound action potentials (ECAPs) represent summation of action potentials generated by neurons of the auditory nerve in response to electrical stimulation. The slope of the ECAP amplitude growth function (AGF) reflects responsiveness or survival of neurons proximal to the stimulating electrode. Goals of the present study were to characterize the magnitude of the AGF slope by electrode site and over time in a cohort of pediatric CI users and measure the degree of correlation of slopes with auditory assessment results.
METHODS: 23 CI users participated in the study, ranging in age from 3 to 12 years. All implanted with 31.5 mm electrode array, full insertion. ECAP AGF slopes measured with all active electrodes intra-operatively, device switch-on, 3-, 6-, 9-, and 12-months post switch-on. Auditory assessments administered at 3-, 6-, 9-, and 12-months post-implantation. Analysis performed by electrode as well as intracochlear electrode site (basal, middle, and apical).
RESULTS: AGF slopes significantly increased according to a basal-to-apical gradient. Slopes were more than twice as large at the apical-most electrode compared to the basal-most (43.1 vs. 20.3 µV/nC). AGF slopes stimulated from basal electrodes significantly increased over time, while those stimulated from apical electrodes significantly decreased over time. No statistically significant correlations were observed between AGF slopes and the test results of any auditory assessment at any timepoint.
CONCLUSION: Observations demonstrate AGF slopes vary substantially, both across the array and over time. No significant associations were observed between AGF slopes and auditory perception skills in this cohort. Due to our relatively small sample size and the heterogeneity of the data, no definitive conclusions regarding these associations can be made here.
PMID:42472922 | DOI:10.1007/s00405-026-10449-9
