There are two categories of physical rehabilitation for facial paralysis. One is peripheral rehabilitation for facial paralysis due to Bell's palsy or end-to-end facial anastomosis. The goal is to prevent or minimize aberrant regeneration. Clinical synkinesis would eventually develop after 4 months provided degeneration is neurotmesis, which could be confirmed by an electroneurogram less than 40% 2 weeks after onset. Conventional voluntary muscle strengthening exercises accentuate regeneration of fibers in not only neuropraxia and axonotmesis but also neurotmesis. To avoid synkinesis or contracture, frequent stretching is indispensable especially during the first 3 months. Stretching massage is more effective than muscle strengthening exercise for patients with complete facial paralysis.
However, the approach is completely different with strong voluntary symmetrical exercises synchronized with using tongue. The facial cortex of the involved face needs to be reorganized after facial nerve reconstruction. The goal is to reorganize the hypoglossal area into facial motor cortex. Critical factors are use-dependent plasticity, earlier intervention and feedback result or reward. To reanimate the involved face with cross-face nerve graft, activation of the contralateral facial cortex dominating the involved face by means of uncrossed facial fibers and graft is needed. Peripheral reconstruction surgery requires central rehabilitation to reorganize facial cortex.
