Electrophysiological and Behavioral Programming Parameters in Patients with Facial Nerve Stimulation Post-Cochlear Implantation.

Background: The aim of this study is to compare patients who develop facial nerve stimulation (FNS) after cochlear implantation (CI) and are managed with a triphasic stimulation pulse pattern (TPP) to those who do not develop FNS regarding the behavioral mapping parameters including the most comfortable loudness level (MCL) charge and amplitude, and the threshold level (THR), as well as the electrophysiological mapping parameters including phase duration (PD) and impedance level.

Methods: A retrospective chart review of the patients who developed FNS at any point after device activation and were managed with TPP was carried out. Electrophysiological and behavioral mapping parameters were retrieved from the programming software database at 3 time points: the time of implantation, the time of shift to TPP, and the last programming session. A control group with no FNS was matched randomly to evaluate any difference in the mapping parameters that could be attributed to FNS.

Results: Sixteen ears with FNS were found to be eligible for inclusion in this study. These cases were matched to 16 ears in the control group. The programming was changed from biphasic pulse pattern (BPP) to TPP (time point -1) after a period of 22.37 ± 14.62 months. Resolution of FNS was achieved in 14 ears (87.5%) by using TPP alone.

Conclusion: The TPP mapping strategy, in addition to decreased phase duration, showed successful results in managing facial nerve stimulation while allowing an increase in the hearing level in the form of increased MCL amplitude.