Peripheral Neural Plasticity in Cochlear Implant Users Across the Lifespan

Area of Science:

• Neuroscience
• Audiology
• Biomedical Engineering

Background:

• Neural recordings in cochlear implant (CI) users offer noninvasive insights into auditory nerve function.
• Current inconsistent methods for acquiring and analyzing these recordings limit clinical utility.

Purpose of the Study:

• To develop and validate an automated method for standardizing the analysis of electrically evoked compound action potentials (eCAPs) in CI users.
• To characterize longitudinal changes in auditory nerve function across the largest CI cohort to date.

Main Methods:

• A multicenter cohort study analyzed eCAPs from CI users using nonlinear curve-fitting models.
• Data included over 1.1 million eCAP recordings from 7,416 patients across multiple US centers.

Main Results:

• The automated method successfully fit approximately 80% of auditory nerve growth functions.
• Auditory nerve response parameters varied with age, sex, electrode location, and duration of implant use.
• Age at implantation, particularly in early childhood, significantly influenced nerve response slopes, indicating peripheral neural plasticity.

Conclusions:

• A robust framework for assessing auditory nerve function and peripheral plasticity in CI users was established.
• Early cochlear implantation is vital for preserving neural health and optimizing long-term auditory outcomes.