July 25, 2024

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Bell’s palsy: Acute idiopathic peripheral facial nerve palsy

Bell's palsy: Acute idiopathic peripheral facial nerve palsy



Bell's palsy: Acute idiopathic peripheral facial nerve palsy. Bell's palsy also known as acute idiopathic peripheral . Because it is acute unilateral paresis (paralysis) or paralysis of unknown etiology, it is also called idiopathic facial nerve palsy and is the most common cause of clinical facial paralysis.


Facial nerve palsy can cause severe psychological and mental disorders to patients, and severely affect social interaction and quality of life. If it is permanent and complete facial paralysis, not paying attention to protect the cornea, it is easy to cause corneal ulcers and cause blindness.


Basic Information

Another name is Acute Idiopathic Peripheral Facial Palsy.  Common causes of neurosurgery. Common causes of cold, fatigue, and common symptoms such as decreased body resistance and immunodeficiency. Facial paralysis, accompanied by decreased taste, dry eyes, nasal congestion, and difficulty chewing



Bell's palsy is different from the original concept of Charles Bell (1829). The pathogenesis has not been finalized yet. At present, there are the herpes simplex virus (HSV-1) infection theory, immune injury theory and acute facial nerve ischemia theory. The main causes are cold, fatigue, decreased body resistance and immune deficiency.


Clinical manifestations

1. Promiscuous group

According to the latest literature report, the incidence of Bell's palsy is 11.5/100,000 to 53.3/100,000/year.

(1) The incidence rate increased significantly between 20 and 40 years old. The ratio of men to women is the same.

(2) Risk factors: diabetes, pregnancy or menstrual period.


2. Symptoms of the disease

(1) Prodromal symptoms: Sudden onset is often induced by cold wind and other stimuli on the head and face, or there is a history of viral infection 7 to 10 days before the onset. May be accompanied or not accompanied by ear or back pain, varying in severity.

(2) Facial paralysis: it can be partial or complete facial nerve palsy. The peak period is 10 to 14 days.

(3) Accompanied by decreased taste, dry eyes, nasal congestion and difficulty chewing.


3. Disease hazards

Facial nerve palsy can cause severe psychological and mental disorders to patients, and severely affect social interaction and quality of life. If it is permanent and complete facial paralysis, careless protection of the cornea can easily cause corneal ulcers and blindness.



1. Otorhinolaryngology head and neck specialist examination

Perform a comprehensive examination of the head and neck position of the otolaryngology. For peripheral facial paralysis of varying degrees on the same side of the affected ear, it is necessary to determine the cause, determine the degree of facial nerve injury, the location of facial nerve injury, and determine the outcome and prognosis of facial nerve recovery.

(1) Determine the degree of facial nerve injury :


①House-Brackmann (1985) Facial nerve injury degree classification

Degree of DamageClassDefinition
NormalIAll areas are functioning normally
Mild dysfunctionIIOnly after careful examination can you see mild weakness, lightly closing the eyes can be completely closed, and mild asymmetry when smiling
Moderate dysfunctionIIIObvious joint movement, but not disfigured
Moderate to severe dysfunctionIVDisfigurement, unable to raise eyebrows, close eyes forcefully but unable to close eyes, asymmetric mouth angles, serious complications
Severe dysfunctionVCan feel the movement of closing my eyes just now, and I can move the corners of the mouth slightly without complications
Completely paralyzedVINo exercise, loss of muscle tone, no complications

②Electrophysiological examination can use nerve excitability test, facial nerve electrogram and electromyographic examination to dynamically observe the recovery of facial nerve function.

Facial nerve electrograms should dynamically observe the number of facial nerve fiber degeneration in 4 to 5 days to 21 days after facial paralysis. If the nerve fiber degeneration reaches 90%, it is a surgical indication of facial nerve decompression. After 21 days of facial paralysis, the facial electromyogram is dynamically observed. If the denervated fibrillation potential gradually changes to monophasic motor unit potential and polyphasic motor unit potential, conservative treatment can be considered.

(2) The location of facial nerve injury can be determined by tear test, stapedius reflex, taste test and submandibular gland flow, but it is not as accurate as the location of traumatic facial paralysis.

(3) Determine the prognosis of facial nerve injury according to the comprehensive judgment of facial nerve electrogram (ENoG), electromyography, stapedius reflex, submandibular gland flow test, patient's age, and the recovery time of facial paralysis.

2. Auxiliary inspection

(1) Gadolinium-enhanced magnetic resonance imaging can show the facial nerve, especially the long T2 signal at the geniculate ganglion. Exclude space-occupying lesions in the internal auditory canal and parotid gland.
(2) Do corresponding inspections for suspected systemic lesions


The diagnosis of Bell's palsy is based on the comprehensive judgment of medical history, general examination, specialist examination, audiology evaluation, electrophysiological examination and imaging examination results. The diagnosis should be based on the method of exclusion to exclude peripheral facial paralysis with a clear cause.

Differential diagnosis

Other diseases that cause peripheral facial paralysis should be excluded, such as herpes zoster auris, otitis media, cholesteatoma of the outer and middle ear and petrous cholesteatoma, trauma (barotrauma, birth injury, and temporal bone fracture, etc.), and benign and malignant tumors in the temporal bone ( Such as acoustic neuroma, facial nerve sheath tumor or fibroma, tympanic body tumor, middle ear cancer, external auditory canal malignant tumor, endolymphatic papilloma, leukemia or metastatic cancer, etc.), parotid gland disease (especially malignant tumor in the parotid gland) and Lyme Facial paralysis caused by diseases, human immunodeficiency virus (HIV), Guillain-Barre syndrome, immune system, metabolic factors, and congenital facial paralysis (Mobius syndrome) or syndrome facial paralysis (Kawasaki syndrome, Melkersson-Rosenthal syndrome) Levy).


It is caused by the incomplete regeneration of the facial nerve and the regeneration of the dislocation of nerve fibers. There are crocodile tears, joint exercises (group exercises), and facial muscle twitches.

Treatment for Bell's palsy: Acute idiopathic peripheral facial nerve palsy

1. Medication

Bell's palsy: Acute idiopathic peripheral facial nerve palsy

(1) Glucocorticoids can reduce inflammation, reduce swelling and reduce immune response in the acute phase, inhibit the inflammatory response of the facial nerve, and reduce the pressure in the facial nerve bony canal with a fixed diameter, thereby reducing the facial nerves caused by edema and thickening. The degree of facial nerve bony canal compression and microcirculation disorder. Therefore, glucocorticoid therapy is the primary and main drug treatment for the disease, but it is not suitable for long-term use. Pay attention to diabetes, tuberculosis, gastric ulcer and pregnant women with caution. Use with caution in children to prevent affecting growth and development. People with hypertension should pay attention to blood pressure control.

(2) Antiviral drugs can interfere with herpes virus DNA polymerase and inhibit DNA replication. Acyclovir (acyclovir) is commonly used, but ganciclovir, famciclovir or valaiclovir can also be used.

(3) Neurotrophic drugs or energy mixtures such as vitamin B1 and vitamin B12 are injected intramuscularly or orally. ATP intramuscularly or intravenously. Coenzyme A intravenously.

(4) Ginkgo biloba extract or other drugs that dilate blood vessels and improve microcirculation are used to improve facial nerve microcirculation by intravenous injection or oral administration.

(5) Analgesics can be used when the ears are severely painful.

(6) Eye ointment and eye drops can be used at night, such as tetracycline or erythromycin ointment, to smear the affected side of the eye, and use an eye mask to protect the eyes. Artificial tears can be used when the tears are reduced.

2. Surgical treatment

Facial nerve decompression: When the facial nerve electrogram shows that the number of facial nerve fiber degeneration reaches 90% to 94%, and it is clinically found that the facial nerve function has not improved and is progressively worsening, facial nerve decompression should be performed in time.

3. Other treatments

(1) Chinese acupuncture can play a role in auxiliary treatment. In the acute phase (1 to 2 weeks), strong stimulation such as acupuncture and moxibustion should not be used. After the acute phase, acupuncture and moxibustion can be used. Medicines for promoting blood circulation and removing blood stasis have auxiliary effects on improving facial nerve microcirculation. Heat-clearing and detoxifying drugs can also be used to fight the virus.

(2) In the acute phase, heat compress, physical therapy, facial massage, etc. can be used as auxiliary treatment such as thermotherapy, magnetic therapy or electromagnetic therapy, ultrashort wave or microwave, laser and direct current drug iontophoresis. Physical therapy such as muscle massage and training can be used during the recovery period. Patients with hemifacial spasm can use magnesium ion introduction, spasm muscle motor point block therapy, such as injection of phenol solution, botulinum toxin and so on.


Bell's palsy is a self-limiting disease with a partial self-healing rate. A randomized double-blind controlled study showed that most patients (especially those with mild or moderate damage) can fully recover their neurological function after treatment with glucocorticoids. The degree of facial paralys is recovery is related to the number of degenerated facial nerve fibers. The recovery of facial paralysis is also related to the outcome. Younger patients recover faster than older patients and have a better prognosis.


Enhance the body's resistance. take more exercise. Avoid cold, overwork and mental stress and other inducements to prevent colds.

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Important Note: The information provided is for informational purposes only and should not be considered as medical advice.