Facial palsy refers to all causes of facial nerve nucleus and its supranuclear pathways (including midbrain! internal capsule! The facial nerve is a mixed nerve, and in addition to innervating the facial expression muscles, its visceral motor fibers innervate the lacrimal gland! Sublingual gland! In addition to innervating the facial expression muscles, its visceral motor fibers innervate the secretion of the submandibular and nasopalatine mucosal glands, and its visceral sensory fibers innervate the taste sensation in the anterior 2/3 of the tongue. Since the lower part of the facial nerve is innervated only by the contralateral cortical nucleus and the upper part is innervated by the bilateral cortical nucleus, the supranuclear facial nerve palsy on one side only appears as facial muscle paralysis below the lid fissure on the opposite side of the lesion. The corners of the mouth are skewed to the diseased side! In the case of supranuclear facial nerve palsy, only the facial muscles below the lid fissure on the side opposite to the lesion are paralyzed. Inability to close the eyes! Loss of nasolabial folds! Drooping corners of the mouth! The facial nerve leaves the brain from the lateral side of the pontine sulcus of the medulla oblongata, enters the inner ear canal through the inner ear door and travels in the facial nerve canal, then enters the parotid gland after exiting the stem mammary foramen to intertwine into a plexus, and then branches to distribute in the face. Clinically, peripheral facial palsy is divided into: 1. Nuclear facial palsy: caused by lesions of the facial nerve nucleus, which can be seen as inflammation of the cerebral bridge! Tumor! Hemorrhage! The facial nerve nucleus is located ventral to the lower reticular structures of the cerebral bridge, therefore, facial nerve nucleus lesions are often accompanied by the involvement of other brain nerves adjacent to the facial nucleus, and often accompanied by damage to the corticospinal tract, and the corresponding symptoms and signs appear, such as Milard–Guble syndrome, which manifests as ipsilateral peripheral facial palsy! Ipsilateral abductor nerve palsy! Foville syndrome, which presents with ipsilateral adductor nerve and facial nerve palsy, combined with gaze palsy and contralateral limb hemiparesis; if the spinal thalamic tract is damaged, it also presents with contralateral hemianesthesia! 2, subnuclear facial palsy: this type is the most common, mostly caused by facial nerve lesions “often caused by viral infection or vascular abnormalities in the facial nerve over the facial nerve canal,” manifesting as paralysis of all facial expression muscles, including the frontalis muscle, with different concomitant symptoms depending on the involved segments of the facial nerve “lesions at the facial nerve out of the stem mammary foramen only manifest as paralysis of the facial expression muscles on the side of the lesion; lesions above the bulbar involvement in the facial nerve In addition to paralysis of the lateral muscles, lesions in the segment above the bulbar involvement of the facial nerve are also associated with loss of taste sensation in the anterior 2/3 of the ipsilateral tongue! Salivary secretion disorder; ipsilateral loss of anterior 2/3 of the tongue when the stapedius muscle is damaged above the branch! Hearing hypersensitivity and salivary disorders; geniculate ganglion lesions in addition to peripheral facial palsy! In addition to ipsilateral loss of taste in the anterior 2/3 of the tongue and auditory hypersensitivity, there is also pain in the affected mastoid region! Hyperalgesia of the auricle and external auditory canal! Herpes of the external auditory canal or tympanic membrane, called Hunt’s syndrome. The most common form of peripheral facial palsy, also known as palsy or idiopathic facial nerve palsy, is peripheral facial palsy due to nonspecific inflammation of the facial nerve in the mastoid foramen. The prognosis of young patients is good; the prognosis of those with a history of cold onset is good; the prognosis of those whose stapedius reflexes are still present 4 d after onset is good; the prognosis of elderly patients with diabetes! Hypertension! The prognosis of facial palsy can be estimated by electromyography. If the recovery is only 10% or less, it will take 6-12 months to recover and will be accompanied by complications such as facial muscle spasm and joint band movements.