Intraoperative Round Window Electrocochleography and Speech Perception Outcomes in Pediatric Cochlear Implant Recipients

Abstract

Objectives: (1) Understand how intraoperative electrocochleograpy (ECoG) is used for assessing residual cochlear function in pediatric implant recipients. (2) Appreciate the utility of electrocochleograpy in predicting speech perception outcomes. Methods: A prospective cohort study of pediatric cochlear implant patients at a tertiary hospital was conducted starting in July 2011 and is ongoing. ECoG recordings were obtained from 77 children (89 ears) during cochlear implantation and provided a total response metric that can quantify the underlying hair cell and neural health. Follow-up speech perception tests were conducted at ≥7 months postoperatively with the phonetically balanced kindergarten (PB-k) word lists (n = 24). PB-k scores were compared to ECoG total response and other clinical and audiologic variables using multiple linear regression analysis in order to construct a parsimonious model for predicting speech outcomes. Results: Postoperative PB-k scores were significantly correlated with ECoG total response ( r2 = 0.32, P = .006) and preoperative pure tone averages (PTA; r2 = 0.41, P = .001). ECoG total response was weakly and inversely correlated with PTA ( r2 = 0.14, P = .001, n = 89). Hierarchical multiple linear regression identified a model for speech perception performance that included preoperative PTA, duration of cochlear implant use, and ECoG total response that predicted about half of the variance in PB-k performance (adjusted r2 = 0.49, P = .002). Conclusions: Intraoperative ECoG recordings are significantly correlated with speech perception outcomes in pediatric cochlear implant recipients and alone can account for a similar proportion of variance in speech perception when compared to other bioaudiometric factors. ECoG provides useful prognostic information about attainment of open set speech perception in children.