Facial nerve stimulation in cochlear implant users - a matter of stimulus parameters?

OBJECTIVES

To describe the influence of stimulus parameters on aberrant facial nerve stimulation in cochlear implant users.

METHODS

Retrospective case series (three ears - two patients). Cochlear implant patients with severe facial nerve stimulation and degraded speech comprehension who underwent re-implantation with Neuro Zti EVO (Oticon Medical).

RESULTS

In all three ears, side effects evoked by aberrant facial nerve stimulation could be resolved and thereby speech comprehension was improved.

CONCLUSIONS

Aberrant facial nerve stimulation in cochlear implant patients was successfully resolved by re-implantation. We hypothesize that one or more of the specific stimulus paramet ers are responsible for this success: combined common ground and monopolar stimulation mode, asymmetric pulse waveform with active anodic leading first phase followed by slow capacitive discharge, and pulse width modulation for loudness coding.