PP1117 - Factors That Influence the Attainment of eSRT in Pediatric Cochlear Implant Users

Abstract:
Electrically evoked stapedius reflex thresholds (eSRT) are an objective measure currently used in cochlear implant (CI) programming to predict upper stimulation levels, especially for children. While adult factors and probe tone have been investigated, there is limited evidence regarding factors that contribute to success in obtaining eSRTs in pediatric CI users. This study aimed to identify patient factors present in successful attempts to obtain eSRTs in pediatric CI users. Additionally, investigators considered modifiable strategies that could result in improved programming for clinical audiologists working with pediatric CI recipients.

Summary:
Electrically evoked stapedius reflex thresholds (eSRT) are an objective measure used in cochlear implant (CI) programming that measures how the static admittance of the middle ear changes in response to electric stimulation from the CI. eSRT has been widely shown to accurately predict upper stimulation levels in CI programming and is especially helpful for the pediatric population (Lorens at al., 2003; Pérez-Rodríguez et al., 2023; Spivak et al., 1994). However, there is limited evidence available pertaining to what factors contribute to success in obtaining eSRTs in pediatric CI users. Previous studies have suggested that higher frequency probe tones may influence likelihood of obtaining eSRTs in children (Carranco Hernandez et al., 2019; Mishra et al., 2017; Palani et al., 2022). A study by Chai et al. found that certain demographic characteristics, such as age and sex, as well as device factors, including electrode location, impact eSRT levels obtained in adult CI users (2024). The question of how these findings translate to the pediatric population remains open.

Preliminary analyses of over 100 implanted ears suggest that children who successfully completed eSRT were implanted at a later age and were older at the time of eSRT compared to those without successful eSRT. However, age at implantation did not significantly differ between children with and without attempted eSRT. Additionally, for those with least one eSRT, the measurements were acquired earlier in the programming process. Clinicians caring for children with middle ear issues were less likely to attempt eSRT.

Authors will investigate clinician-reported methods utilized to attain any eSRT (e.g., wake state, probe tone, probe ear, electrodes tested, stimulus type, activity during measurement, etc.). Moreover, further analyses will describe factors that caused audiologists to forgo eSRT measurement. These results provide a framework for strategizing timing for measuring eSRTs as well as procedural modifications that can be implemented to successfully obtain eSRTs in children.

Brief Summary of Clinical Takeaways:
The clinic takeaway for this session is that eSRT is an achievable objective method in programming cochlear implants, and clinicians should especially attempt eSRT for pediatric patients earlier on in the programming process. Knowledge of various patient and procedural considerations may increase likelihood of successfully obtaining at least partial eSRTs.

Assumptions
Requires a basic understanding of electrically evoked stapedius reflex thresholds (eSRT) and how it is obtained, knowledge regarding cochlear implant (CI) programming in the pediatric population, and how eSRT is utilized for CI mapping.