Assessment of cochlear implant candidacy in patients with cochlear nerve deficiency using the P1 CAEP biomarker

Objective: The goal of this report was to ascertain the efficacy of the P1 cortical auditory evoked potential (CAEP) biomarker as an objective tool to assist in the evaluation of cochlear implant (CI) candidacy in children with a radiological diagnosis of cochlear nerve deficiency (CND). Methods: Retrospective case study review of audiological and radiological findings was performed in four pediatric patients identified with CND and severe-to-profound sensorineural hearing loss. Cortical auditory evoked potential testing was conducted, and the presence and latency of the P1 component were analyzed. Results: Three out of four children demonstrated robust P1 CAEP responses, indicating activation of the central auditory pathways by auditory stimulation, despite the diagnosis of CND. These children were considered good candidates for cochlear implantation. Discussion: Although cochlear implantation in children is a fairly routine procedure, cases exist for which implant candidacy is questionable. Among these cases are children with CND. In these children, cochlear implantation may be contraindicated due to the likelihood that the implant electrodes may not stimulate the VIII nerve adequately. Magnetic resonance imaging (MRI) is considered the gold standard in the assessment of CND, but this measure is not always sufficient to determine CI candidacy in cases of CND. The addition of the P1 CAEP measurement to the usual electrophysiological, audiometric, and radiological test battery may prove to be useful in determining CI options for children with CND.