Facial Function Reanimation by Electrical Pacing in Unilateral Facial Paralysis.

Overview

Purpose of the trial is to study the activations of paralyzed facial muscles in a unilateral facial nerve palsy with a multi-channel electrical stimulator. The principle of the device is to measure muscle activity of the healthy side of the face by surface electromyography (EMG) and to use this information to stimulate the corresponding muscles of the paralyzed side. The ultimate goal is to develop a prosthetic device for persons with a facial nerve palsy. The trial consists of several different studies. The studies' aims are 1. To study activations of paralyzed facial muscles by the electrical stimulation. 2. To study different stimulation pulse waveforms, frequencies, and electrode placement and their effect on the muscle activations and the tolerability of the stimulation. 3. To study whether a symmetrical movement on the paralyzed side can be achieved with electrical stimulation when compared to the movements of the healthy side. 4. To study tolerability of stimulation-elicited eye blink when watching a film and the effect of the stimulation-induced blink on the eye symptoms, the visual acuity, and the effects of the stimulation on the lacrimal fluid. 5. To develop a method for facial pacing, i.e. measuring the muscle activations on the healthy side of the face and to use this information to stimulate and activate the healthy side of the face. Forty subjects with a chronic facial nerve palsy are recruited to the studies. Each subject can participate in one or several studies. Another forty subjects with an acute facial nerve palsy are recruited to the study on the tolerability and effect on the eye symptoms. Additionally, altogether ninety healthy volunteers are recruited to the studies in order to gather preliminary information on the tolerability and the effects of the stimulations.