Effect of Taking a Break From Cochlear-Implant Use for Resolving Facial-Nerve Stimulation: A Case Series.

OBJECTIVE

To determine if a break from cochlear-implant (CI) stimulation reduces auditory electrical stimulation levels, to manage secondary facial nerve stimulation (FNS).

STUDY

DESIGN

Retrospective case review.

SETTING

Multidisciplinary clinic within a CI tertiary-care center.

PATIENTS: Four adult CI users exhibiting FNS at stimulation levels needed for auditory perception.

INTERVENTION: Taking a break from CI stimulation (temporary nonuse) to test the hypothesis that FNS arose from increasing auditory stimulation. An increase in auditory stimulation levels may stem from a decrease in auditory-nerve excitability due to overstimulation. A break would allow recovery of excitability, leading to lower current use and less cross-stimulation of the facial nerve. Break duration ranged between 1 week to several months.

MAIN OUTCOME MEASURES: Lower and upper electrical stimulation levels required for hearing (N=3), reported or observed FNS (N=4), and FNS thresholds (N=1) before and after the break.

RESULTS

In all cases for whom stimulation levels for hearing were measured both before and after a break ( Patients 1 to 3 ), these decreased after the break. In 2 of these cases, the decreased stimulation levels helped to manage persistent FNS. In one other case ( Patient 4 ), FNS thresholds decreased slightly or remained unchanged after the break and the stimulation of most electrodes continued to lead to FNS with no change in auditory perception.

CONCLUSIONS

A break from CI stimulation could be considered to manage persistent FNS when auditory stimulation levels increase over time. In some cases, a break may reduce the stimulation levels required for hearing, minimizing or eliminating the occurrence of FNS. Further research is needed to determine the biological mechanisms involved, optimize the duration of the break, as well as determine its long-term effectiveness.