Home-based Functional Electrical Stimulation for Treatment of Patients with Facial Nerve Paralysis.

Peripheral facial paralysis results in complete loss of contractibility in facial muscles, atrophy and asymmetry. Patients performed functional electrical stimulation (FES) home training twice daily over 1 year to show its effect and define stimulation parameters. A specific response was obtained in all 10 patients. Since the mean phase duration (PD) could be reduced (155.0 ± 55.0 to 51.0 ± 12.4 msec), this allowed the mean stimulation frequency to be increased (1.3 ± 0.5 to 5.0 Hz ± 1.5 Hz). The PD reduction to generate the same charge increased the voltage (16.2 ± 2.5 to 27.2 V ± 5.9). A suitable combination of PD and amplitude elicited a selective response without activation of other facial muscles using a PD of ≥ 25 ms (> 25 000 µs). FES changes the stimulation parameters for improving the training effect on denervated facial muscles. It prevents denervation atrophy and stops facial asymmetry.