Facial muscle spasm, also known as facial muscle twitching. It is a condition of involuntary twitching of the face on one side. The facial muscles are controlled by the facial nerve, which emanates from the brainstem and exits the skull via the lower part of the internal auditory canal. The facial nerve is primarily a motor nerve, controlling the movement of the eyelids, mouth and lips. Facial spasm is relatively rare, with 8 cases per 100,000 in the U.S. It is more common in women, with a male to female ratio of about 2:3. The average age is 45 years. Symptoms 90% of patients start with twitching of the orbicularis oculi muscle and then gradually involve the entire face downward. Early symptoms are intermittent twitching of the eyelid muscles, which can cause the eyes to close. 10% of patients start with the chin and progress upwards. It is often not accompanied by pain, but causes distress and affects the patient’s normal expression and appearance. The spasm may spread to one side of the face or may be confined to the upper or lower part. Tearing may occur. Symptoms may also occur during sleep. Diagnosis History and routine neurological examination can diagnose facial spasm. MRI can rule out facial nerve compression due to tumors, aneurysms or arteriovenous malformations. Electromyography and nerve conduction velocity tests can measure the electrical activity of the facial muscles and nerves. Treatment There are three treatment methods: medication, local injection of botulinum toxin and microvascular decompression, but so far, only microvascular decompression surgery is an effective treatment. Medication: Valium drugs such as diazepam, the intramuscular reliever baclofen, and the antiepileptic drugs carbamazepine or dalantin can be used. These drugs may be effective in patients with milder symptoms, but have greater side effects such as drowsiness, unsteady walking, nausea, skin erythema and addiction. Various medications also have their own side effects and patients need to be checked regularly to prevent serious side effects. Botulinum toxin local injection: Botulinum toxin is a highly toxic protein substance produced by botulinum toxin bacteria that can block neuromuscular electrical conduction causing muscle numbness. The neurotransmitter that conducts between the nerve muscles is acetylcholine, which Botox blocks from being released and the muscle loses its contraction signal. Botox is injected via a syringe into the facial muscle where the twitch occurs, and the effect usually appears after 3 days and can last up to 3 months. The treatment can be repeated, but the effect gradually decreases because over time, the patient’s body develops antibodies to Botox that affect its efficacy. Side effects include facial weakness, drooping eyelids, and eye sensory allergy discomfort. Surgery: If medications and botulinum toxin treatment are ineffective or have large side effects and the patient cannot tolerate these side effects, microvascular decompression surgery can cure the disease, and more and more physicians are advocating this surgical treatment because it is less invasive and more effective (surgery is indicated if brief medications are ineffective and imaging is clear that the facial nerve is compressed). Although surgery is currently the only effective treatment for facial spasm, it is never the first treatment option. A small incision is made behind the ear (posterior suboccipital sigmoid sinus), a 3×2.5 cm bone window is made, the meninges are cut, the pontocerebellar angle is entered, the VII and VIII cranial nerves are identified, and if an occupying lesion or arachnoid adhesion is found, it is removed and dissected. A muscle sheet can be used to fill in the space between the vessel and the nerve. More than 90% of patients return to normal work and life. The main complications of this procedure are transient unilateral facial paralysis (11%) and deafness (3%). Treatment results: 85% disappeared immediately after surgery; 10% had significantly reduced spasticity after surgery; 2% had reappearance of spasticity 1 month after surgery; 7% had recurrence. Early efficiency was 95% and long-term efficiency was 90%.