The symptoms of facial palsy include loss of frontal wrinkles, enlarged eye fissures, flattened nasolabial folds, drooping corners of the mouth, and skewed corners of the mouth to the key side when the teeth are exposed. When eating, food residues are often retained in the gap between the teeth and cheeks on the sick side, and saliva often flows down from that side. For example, when the nerve is cut, the muscle loses the ability to contract, the action potential will disappear immediately. degenerative condition has occurred. If the fibrillation and motor unit potentials have disappeared, then the muscle is completely fibrotic and there is no longer an indication for surgery. 2. Neurography: The facial nerve branch at the mastoid foramen is stimulated by bipolar stimulation, similar to the maximum stimulation test, and the difference between the two sides is compared, i.e. the percentage of nerve degeneration. When the degeneration rate reaches more than 90% in two weeks, the value is not fully recovered. Since this test is not able to identify the degree of damage as axonal disintegration or nerve disintegration, it can only be used to assess the likelihood of nerve failure to recover.