Is the Presence of eCAP Intraoperatively a Predictor of Cochlear Implant Outcomes in Adults?

Introduction: The electrically-evoked compound action potential (eCAP) is commonly used to assess the physiological integrity of the auditory nerve's first neuron in cochlear implant (CI) users. Electrical stimulation of this neuron is essential for transmitting auditory signals to the auditory cortex, enabling the recognition of acoustic cues. Objective: To determine whether the presence of intraoperative eCAP influences CI outcomes in adult individuals with pre- or postlingual deafness. Methods: The present retrospective cross-sectional study included adults with hearing loss of various etiologies who received a CI, either with pre- or postlingual deafness. Data on intraoperative eCAP results and speech recognition test outcomes after 12 months of consistent CI use were extracted from medical records. Results: Data from 121 ears were analyzed, comprising 101 individuals with post- and 20 with prelingual deafness. In the overall sample, 90.9% exhibited eCAP presence intraoperatively. In the prelingual group, eCAP was present in 100% of cases, while 89% of the postlingual group showed eCAP presence. Individuals with intraoperative eCAP demonstrated significantly better speech recognition performance compared with those without eCAP, in both open- and closed-set tests. Conclusion: In adults with postlingual deafness, 89% exhibited intraoperative eCAP, which correlated with significantly better speech recognition outcomes. In contrast, the prelingual group demonstrated intraoperative neural responses, but no significant correlation with speech recognition performance was observed.