Optimizing Cochlear Implant Outcomes in Cochlear Nerve Aplasia: The EMPES Protocol (Early Implantation, Modiolar Proximity, and Early Switch-On).
Abstract
Objective
To evaluate the efficacy of EMPES [Early implantation, Modiolar Proximity (MP), and Early Switch-on] approach in bilateral cochlear nerve (CN) aplasia. STUDY
Design
Retrospective cohort study.
Setting
Tertiary referral center. PATIENTS Forty-six children (86 ears) with bilateral CN aplasia underwent cochlear implantation (CI) between 2011 and 2024 at 2 tertiary centers.
Intervention
For electrophysiological comparison, CI was performed using CI24RE-CA electrodes without pull-back (conventional implantation) or a slim modiolar electrode with pull-back (better MP). For speech outcome comparison, the conventional approach group comprised conventional implantation cases with ≥12-month follow-up, and the EMPES approach group comprised those in the better MP group implanted before 12 months and followed for ≥12 months. MAIN OUTCOME MEASURES Mechanistic endpoint, intraoperative ECAP positivity; functional endpoint: longitudinal Categories of Auditory Performance (CAP) scores up to 48 months.
Results
The better MP group showed higher intraoperative ECAP positivity, which translated into better postoperative outcomes. The EMPES approach demonstrated clear superiority in auditory performance up to 12 months [CAP score 3.00 (2.00 to 4.00) vs. 1.50 (1.00 to 2.25); P=0.010], with significantly fewer poor responders (CAP<2) at 1 year, and maintained narrower variability in median CAP scores through 36 months, indicating more stable auditory progress compared with the conventional approach. No clear association was observed between MRI-based CN aplasia severity and either ECAP positivity or audiological outcomes.
Conclusions
The EMPES approach improves postoperative audiological outcomes during critical language periods and is recommended for bilateral CN aplasia to enhance language development and potentially reduce the need for auditory brainstem implantation.