Surgical rehabilitation of reversible facial palsy: facial--hypoglossal network system based on neural signal augmentation/neural supercharge concept.

To obtain symmetric appearance in facial palsy patients, it is important to retain any remaining potential of the compromised facial mimetic muscles. The purpose of the present study was to introduce surgical rehabilitation based on neural signal augmentation/neural supercharge concept for the treatment of reversible facial palsy patients. With construction of facial-hypoglossal network system using end-to-side neurorrhaphy technique, both facial and hypoglossal motor signals are provided to the compromised facial mimetic muscles. It is hypothesised that the remaining potential of incompletely or completely paralysed muscles without atrophy is activated by a neural 'supercharge' effect. To date, nine patients presented with reversible facial palsy have been treated by surgical rehabilitation with facial-hypoglossal network system in our institutes. Facial mimetic muscle function evaluated by the House-Brackmann grading system was improved from grade IV-VI to II-III in this series. The postoperative ENMG findings showed double innervation of the mimetic muscles supplied by the facial and hypoglossal donor motor sources. Hemiglossal dysfunction and mimetic muscle synkinesis associated with tongue motion were never seen with an average follow-up period of 21 months after surgery. This reconstructive concept offers a significant advantage for the treatment of the facial palsy patients with persistent incomplete type and reversible complete type without distinct mimetic muscle atrophy.