Factors Influencing Aberrant Facial Nerve Stimulation Following Cochlear Implantation: A Systematic Review and Meta-analysis

Objective:The purpose of this study was to systematically evaluate the literature to evaluate the rate of and associated factors with aberrant facial nerve stimulation (AFNS) following cochlear implantation. Additionally, management strategies for AFNS were assessed.Data Sources:A systematic search was performed in PubMed, Cochrane Database of Systematic Reviews, and Web of Science to identify peer reviewed research.Study Selection:Eligible studies were those containing peer-reviewed research in English addressing AFNS following cochlear implantation. Studies with paired data were included in the meta-analysis.Data Extraction:Three investigators independently reviewed all articles and extracted data. Bias was assessed using the National Institutes of Health Study Quality Assessment Tool.Data Synthesis:Thirty-seven articles were included, representing 5,694 patients. The overall reported AFNS rate was 5.6% (range, 0.68-43%). Array type demonstrated a significant association with AFNS with lateral wall electrodes having a higher odds ratio than perimodiolar electrodes (odds ratio [OR] = 3.92, 95% confidence interval [CI] 1.46-10.47, p = 0.01). CI recipients with otosclerosis were also more likely to experience AFNS compared with non-otosclerosis pathology (OR = 13.73, 95% CI 3.57-52.78, p < 0.01). Patients with cochlear malformations had an overall AFNS rate of 28% (range, 5.3-43%) and those with otosclerosis had an overall rate of 26% (range, 6.25-75%). Reprogramming with or without electrode deactivation was successful for AFNS elimination. Four patients of 3,015 required explantation.Conclusion:Array type and underlying cochlear pathology are associated with AFNS and implant reprogramming is an overall successful management strategy. Further research is needed to elucidate mechanism of AFNS and develop management strategies that limit impact on hearing outcomes.