The audiologic characteristics for children with cochlear nerve deficiency and the association with the outcome of cochlear implant surgery

Objective The objective of this study was to investigate the audiological characteristics of children with cochlear nerve deficiency (CND) and their correlation with cochlear implantation (CI) prognosis.Methods The records of 48 patients (24 with bilateral CND and 24 with no inner ear malformations (IEMs)) who underwent unilateral CI were reviewed. Preoperative audiometric, postoperative electrical stimulation auditory brainstem response (EABR), and auditory performance measures were also assessed.Results CND patients demonstrated a significantly higher positive wave detection rate (41.67%) compared with controls (0%, p < 0.001). Ears with isolated cochlear nerve canal stenosis (CNCs) had higher positive wave detection rates (62.5%) than those with additional semicircular canal/vestibular abnormalities (0%). Ears with positive waves demonstrated better multiple frequency steady-state response and postoperative EABR thresholds than those without positive waves. The categories of auditory performance (CAP) scores at the 2-year follow-up were significantly higher in patients with positive waves than in those without positive waves (4.17 ± 0.58 vs. 3.58 ± 0.51).Conclusions The presence of a distinctive positive waveform in auditory brainstem response (ABR) testing may indicate preserved residual auditory pathway integrity in CND patients. This characteristic may serve as a prognostic indicator for CI outcomes, warranting further investigation in larger, longitudinal cohorts.