Long-Term Stability of Electrical Stimulation in Children with Bilateral Cochlear Implants

Area of Science:

• Neuroscience
• Biomedical Engineering
• Audiology

Background:

• Long-term stability of neural responses and stimulation levels in cochlear implant (CI) users is not well understood.
• Previous studies suggest stabilization within months, but reprogramming remains time-consuming.

Purpose of the Study:

• To investigate the long-term resilience of the auditory nerve to CI stimulation.
• To identify changes in programmed stimulation levels over time in pediatric CI users.

Main Methods:

• Analysis of 14,072 stimulation parameter sets (MAPs) from 1,291 devices in 664 children.
• Evaluation of 23,215 electrophysiological auditory nerve thresholds and 17,849 amplitude growth function slopes.
• Longitudinal follow-up data collected between September 2003 and July 2022.

Main Results:

• Stimulation parameters (C-levels and T-levels) stabilized within 12 months post-implantation for approximately 75% of devices.
• Electrophysiological measures showed minimal annual changes: slopes averaged 0.03 μV/CU/year and thresholds 0.35 CU/year.
• Age at implantation did not affect electrophysiological measures but correlated with decreasing stimulation levels in younger children.

Conclusions:

• Findings indicate long-term stability of neural responses and CI programming.
• Potential exists to redirect clinical resources from frequent reprogramming to other care areas after the initial year of CI use.