Implantable Facial Pacemaker: Definition of electrostimulation parameters for implantable solutions to treat facial palsy

Introduction An implantable device to stimulate muscles or nerves could help restoring natural facial movements in patients suffering from different types of facial palsy. However, its functionality depends on the stimulation capability to exclusively activate the target muscle and to prevent patient’s discomfort/pain. The aim of our work is to evaluate whether needle electrodes (mimicking implantable electrodes) can be used to selective activate the M. zygomaticus (ZYG) in patients suffering from facial palsy of different grades and for different periods of time

Methods So far 9 patients have been recruited to the study. 2 monopolar needle electrodes placed under ultrasound guidance were used to deliver bipolar electrostimulation to the ailing ZYG. The selectivity of the stimulation was assessed by visual detection of the movement of the respective mouth corner, in absence of contractions or co-contractions of other facial muscles or discomfort for the patients

Results Selective ZYG response was observed in 7/9 (78%) patients stimulated with a pulse width (PW) between 0.5 and 2ms (median 1.7 ms) and an amplitude comprised between 1.5 and 2.5mA (median 1.5mA). No adverse events or unspecific response of other facial muscles were observed in any of the assessed patients. The duration of the facial paralysis did not affect the amplitude or the PW necessary to obtain the selective stimulation of the ZYG

Conclusions Our initial results indicate that the use of stimulation parameters compatible with implantable devices can be used to deliver a selective and safe stimulation of a specific paralyzed facial muscle. Placement of the electrodes under ultrasound guidance ensure the safety of the procedure. Important steps towards an implantable facial pacemaker were done

Poster-PDF A-1508.pdf

MED-EL Elektromedizinische Geräte GmbH

Conflict of interest

Der Erstautor gibt keinen Interessenskonflikt an.

Publication History

Article published online:
13 May 2021