The effect of cochlear implantation in patients with unilateral sensorineural hearing loss with and without bony cochlear nerve canal stenosis

Objective To evaluate outcomes of cochlear implantation (CI) in patients with unilateral sensorineural hearing loss (USNHL) and explore effects and stimulation current in USNHL patients with bony cochlear nerve canal (BCNC) stenosis versus normal cochlear nerve canals. Methods A prospective study was conducted on 23 USNHL patients who underwent CI (MED-EL) from May 2019 to March 2023. Preoperative CT and MRI scans were performed to measure BCNC width. Subjects were divided into BCNC stenosis (BCNC-S) and BCNC normal (BCNC-N) groups. Hearing thresholds, speech recognition scores (SRS), sound localization ability, and auditory/musical abilities were assessed before and two years after CI. Differences were determined using Stata statistical software, with significance defined as p < .05. Results Eleven patients were diagnosed with BCNC stenosis. CI significantly improved SRS under noisy conditions ( p = .027) and sound localization ability ( p < .05), as well as auditory and musical quality ( p < .05). No significant differences in outcomes were found between BCNC-S and BCNC-N groups. BCNC-S group had higher stimulation current than BCNC-N group. Conclusions CI provides similar improvements for USNHL patients with or without BCNC stenosis. Significance The findings will contribute to the understanding of cochlear implant outcomes in patients with USNHL and BCNC stenosis.