Cochlear Implantation in Far Advanced Otosclerosis: A Systematic Review and Meta‐Analysis

Abstract

Objective To evaluate speech outcomes and facial nerve stimulation (FNS) rates in patients with far advanced otosclerosis (FAO) after cochlear implantation. Methods A systematic review was performed using standardized methodology of Medline, EMBASE, PubMed, Cochrane, and Web of Science databases. Studies were included if adults with FAO underwent cochlear implantation. Exclusion criteria included concurrent otologic history (e.g., Meniere's disease, superior canal dehiscence), non‐English‐speaking implant users, case reports, abstracts, and letters/commentaries. Bias was assessed using the Newcastle‐Ottawa Scale for cohort studies and the National Institute of Health Scale for case series. The primary outcome measure was speech discrimination and the secondary outcomes were rates of partial insertion and FNS. Results Twenty‐seven studies evaluated cochlear implantation in FAO. Due to the heterogeneity of testing methods, statistical pooling of speech discrimination was not feasible, but qualitative synthesis indicated a positive effect of implantation. Pooled rates of FNS were 18% (95% confidence interval, CI 12%–27%) and the rate of partial insertion was 10% (95% CI 7%–15%). Conclusion Cochlear implantation in FAO demonstrates significant gains in speech discrimination scores with higher rates of FNS and partial insertion. Laryngoscope, 133:1288–1296, 2023

Facial nerve stimulation in adult cochlear implant recipients with far advanced otosclerosis

“…In Table 5, we summarized 22 articles reporting FNS after cochlear implantation for a FAO, published between 2000 and 2022. FNS incidence varied highly among studies, ranging from 0% incidence 19,20 up to 57% 13,14 . The high heterogeneity among studies regarding inclusion criteria, radiological extension of otosclerosis, number of patients, and cochlear implant technology may explain this variability 21,22 .…”

“…FNS incidence varied highly among studies, ranging from 0% incidence 19 , 20 up to 57%. 13 , 14 The high heterogeneity among studies regarding inclusion criteria, radiological extension of otosclerosis, number of patients, and cochlear implant technology may explain this variability. 21 , 22 In a meta‐analysis on factors influencing FNS after cochlear implantation, FNS incidence was higher in the group with otosclerosis (28%) compared to patients with other etiologies (3.5%), with an odds ratio of 13.73 predicting FNS in this population.…”

“…Whereas the presence of FNS at 1‐year was not a prognostic factor, long‐term analysis of the entire cohort showed a negative effect of FNS on speech performance in both quiet and noise, possibly due to a higher percentage of deactivated electrodes. Regarding the effect of FNS on speech performance, conflicting results are found in literature 9,14,16,24,25,36 in patients with FNS. Considering previous stapes surgery, some studies 7,8,26 did not find negative impact of previous stapedotomy on speech performance whereas others observed poorer performance, as in our study 9…”

“…Cochlear implant recipients with FAO are more likely to experience facial nerve stimulation (FNS), 13,14 usually explained by a reduction of impedance and higher conductivity due to spongiotic bone properties. Incidence of FNS in otosclerotic patients widely varies between studies, ranging from 0% to 57% 9,13,15 .…”

“…The choice between these two strategies takes into account the type, severity, and evolution of hearing loss in both ears, patient desires, cochlear implant cost, and surgical risks. 7,8,12 Cochlear implant recipients with FAO are more likely to experience facial nerve stimulation (FNS), 13,14 usually explained by a reduction of impedance and higher conductivity due to spongiotic bone properties.…”