What is peripheral facial paralysis and what are its symptoms?

Facial paralysis is called "crooked mouth wind" in the north and "hanging line wind" in the south. In Western medicine, facial nerve paralysis is divided into two types: central and peripheral. It can occur in all age groups, mostly in young and middle-aged people, and is often attributed to mastoiditis. So what is peripheral facial paralysis?

Peripheral facial palsy

Peripheral facial paralysis, also known as Bell's palsy or facial neuritis, is peripheral facial muscle paralysis caused by nonspecific inflammation of the facial nerve in the facial nerve canal. The common symptoms are facial paralysis and inability to complete actions such as raising eyebrows, closing eyes, and puffing lips. It is a common and frequently occurring disease that can occur at any age. The incidence is similar in men and women. The vast majority of cases are unilateral, and bilateral cases are rare.

Causes

Cold, viral infection (such as herpes zoster, herpes simplex, mumps, cytomegalovirus, etc.) and autonomic nervous system instability can cause local neurotrophic vasospasm, leading to facial nerve ischemia and edema. Since the facial nerve canal is a bony cavity with limited volume, if the facial nerve edema is obvious, the facial nerve will be compressed, which can cause axon degeneration to varying degrees. This may be an important reason for the poor recovery of some patients.

Clinical manifestations

1. Acute onset, symptoms reach peak within a few hours or 1 to 3 days, and may be accompanied by pain in the mastoid area behind the ear, inside the ear, or at the mandibular angle.

2. Paralysis of the facial expression muscles on one side is the prominent symptom, with crooked corners of the mouth, drooling, air leakage when speaking, air leakage when puffing up the cheeks and whistling, and food retention between the teeth and cheeks on the affected side.

3. It may be accompanied by loss of taste, decreased saliva, hyperacusis, pain in the mastoid area of ​​the affected side, decreased sensation in the auricle and external auditory canal, and herpes in the external auditory canal or tympanic membrane.

Physical examination showed that the forehead wrinkles on one side of the face disappeared, the palpebral fissure became larger, the nasolabial groove became shallower and flatter, the corner of the mouth on the affected side drooped, and the corner of the mouth tilted toward the healthy side when showing teeth. When puffing the cheeks and whistling, air leaked from the affected side. Unable to raise forehead or frown, eyelids close weakly or incompletely. When the eyes are closed, the eyeballs rotate upward and outward, revealing the white sclera, which is called Bell's sign.