Electrically evoked cortical potentials recorded directly from cochlear implant system: Feasibility in pediatric users and clinical relevance

Intracochlear electrodes in cochlear implants (CIs) offer a novel method for recording auditory brain activity without external EEG equipment, addressing challenges in pediatric CI users. This study tested the feasibility of recording electrically evoked cortical auditory evoked potential (eCAEPs) directly via the CI system. Twenty children and three adults with bilateral Advanced Bionics CIs participated. A brief electrical stimulus was delivered to one CI, while the contralateral CI recorded responses using a basal electrode referenced to the case. Each session included stimulus and non-stimulus sweeps, with averaging over 600 ms revealing clear eCAEP patterns. All participants exhibited obligatory P1, N1, and P2 peaks within a test duration of under five minutes. The method showed good test-retest repeatability and expected latency shifts occurred with stimulus level adjustments. Compared to scalp recorded EEG, intracochlear recordings produced significantly larger amplitudes with similar latencies. Early-implanted children displayed distinct eCAEP patterns, and better performing CI users had earlier P1 responses. This recording approach provides a robust, non-invasive tool for monitoring CI users, particularly young children, offering potential advancements in post-implantation assessment and intervention by eliminating external equipment while ensuring reliable recordings.