Performance of cochlear implant recipients fitted with triphasic pulse patterns.

Area of Science:

• Audiology
• Neurosurgery
• Biomedical Engineering

Background:

• Unintended facial nerve stimulation (FNS) is a complication of cochlear implantation (CI).
• Traditional biphasic pulse stimulation can lead to FNS, impacting audiological performance.
• Managing FNS is crucial for optimizing outcomes in CI recipients.

Purpose of the Study:

• To evaluate the effectiveness of triphasic pulse pattern stimulation in managing FNS.
• To compare audiological and speech outcomes in CI patients before and after switching to triphasic stimulation.

Main Methods:

• Retrospective study of 11 CI patients (16 ears) experiencing FNS.
• Comparison of audiological data (pure tone audiometry, speech reception thresholds, speech discrimination scores, comfortable levels, dynamic range) between biphasic and triphasic stimulation.
• Analysis of medical records for demographic and radiological data.

Main Results:

• Triphasic pulse stimulation successfully resolved FNS in all cases, sometimes combined with channel deactivation.
• Speech discrimination scores improved significantly with triphasic stimulation (75.25% ± 26.13%) compared to biphasic (58.25% ± 26.13%).
• Triphasic stimulation resulted in higher maximum comfortable levels and a wider dynamic range.

Conclusions:

• Triphasic pulse pattern stimulation is effective in controlling FNS after CI.
• This strategy enhances audiological performance, particularly speech discrimination.
• Switching to triphasic stimulation is recommended for CI patients with FNS before considering additional surgical interventions.