Mirror Biofeedback Rehabilitation after Administration of Single-Dose Botulinum Toxin for Treatment of Facial Synkinesis

Objective. The efficacy of facial biofeedback rehabilitation with a mirror after administration of a single dose of botulinum A toxin on facial synkinesis was examined in patients with chronic facial palsy. Study Design. Prospective clinical study. Setting. University hospital. Subjects and Methods. The present study includes 8 patients with Bell palsy and 5 with herpes zoster oticus showing facial synkinesis. A single dose of botulinum A toxin was used as the initial process of facial rehabilitation. Patients then continued a daily facial biofeedback rehabilitation with a mirror at home. They were instructed to keep their eyes symmetrically open using a mirror during mouth movements. The degree of oralocular synkinesis was evaluated by the degree of asymmetry of eye opening width during mouth movements (% eye opening). Results. After administration of a single dose of botulinum A toxin, temporary relief of facial synkinesis was observed in all patients. Patients were then instructed to continue the facial biofeedback rehabilitation with a mirror for 10 months. The mean values of the percent of eye opening during 3 designated mouth movements that included lip pursing /u:/, teeth baring /i:/, and cheek puffing /pu:/ increased significantly after 10 months when the effects of botulinum A toxin had completely disappeared. Conclusion. These findings demonstrate that facial biofeedback rehabilitation with a mirror after administration of a single dose of botulinum A toxin is a long-lasting treatment of established facial synkinesis in patients with chronic facial palsy.