Electrical Impedance as a Biomarker for Inner Ear Pathology Following Lateral Wall and Peri-modiolar Cochlear...

Area of Science:

• Otolaryngology
• Biomedical Engineering
• Neurosurgery

Background:

• Impedance spikes in cochlear implants can indicate inner ear issues post-surgery.
• Understanding the correlation between impedance changes and clinical events is crucial for patient management.

Purpose of the Study:

• To investigate the relationship between cochlear implant impedance spikes and inner ear pathologies.
• To compare the incidence of impedance spikes between lateral wall and peri-modiolar electrode arrays.
• To correlate impedance spikes with specific clinical events like hearing loss and vertigo.

Main Methods:

• Analysis of impedance data from 770 cochlear implant recipients (CI422 and CI512).
• Definition of impedance fluctuation as a median rise of ≥ 4 kΩ.
• Review of medical records for 189 patients to identify clinical events.

Main Results:

• Lateral wall electrodes (CI422) had a higher impedance spike rate (17%) compared to peri-modiolar electrodes (CI512) (12%).
• Impedance spikes significantly correlated with clinical events (hearing loss, vertigo, tinnitus) (56% in spike group vs. 22% in non-spike group).
• Peri-modiolar electrodes tended to spike earlier than lateral wall electrodes.

Conclusions:

• A significant association exists between cochlear implant impedance spikes and postoperative inner ear events.
• Lateral wall electrodes show a slightly higher incidence of impedance spikes.
• Monitoring cochlear implant impedance may aid in the early detection and prevention of inner ear events.