Neural response telemetry with the nucleus CI24M cochlear implant

Area of Science:

• Otolaryngology
• Biomedical Engineering
• Neuroscience

Background:

• Cochlear implantation is a complex procedure requiring precise device calibration.
• Accurate intraoperative and postoperative testing is crucial for optimizing patient outcomes.

Purpose of the Study:

• To review and detail the intraoperative and postoperative testing protocol for the Nucleus CI24M cochlear implant system.
• To describe the application and methodologies of neural response telemetry (NRT) for auditory nerve action potential measurement.
• To evaluate the utility of NRT and visual detection of electrical stapedius muscle reflexes (VESR) in cochlear implant programming.

Main Methods:

• Developed a specific protocol for intraoperative testing including device integrity, VESR, and NRT.
• Utilized commercial software (WIN-DPS and NRT) for the Nucleus CI24M system.
• Correlated NRT thresholds with behavioral responses in 28 adult and pediatric patients.

Main Results:

• Successfully completed intraoperative testing (electrode integrity, NRT, VESR) on 12 patients.
• Confirmed normal implant function in 27 out of 28 CI24M patients; one pediatric device failure occurred due to head trauma.
• Obtained postoperative NRT results from an additional 10 patients.

Conclusions:

• Device and electrode array function measurement is straightforward with CI24M software, applicable both intraoperatively and postoperatively.
• VESR and NRT measurements are valuable tools for programming cochlear implants.
• These techniques provide essential target settings for speech processors, particularly beneficial for pediatric cochlear implant users.