Abstract
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.