Facial muscle spasm is an episodic twitch of the face. Most of them are paroxysmal involuntary twitching of facial muscles on one side (individually on both sides). Generally, the initial manifestation of the disease is twitching of the eyelid and the corner of the eye (orbicularis oculi muscle spasm) on one side, and the twitching range gradually expands downward, causing twitching of the periorbital area, the corner of the mouth (orbicularis oris muscle) and facial muscles (facial expression muscle) on one side of the face.
I. Disease manifestations.
It mostly starts in middle age and is slightly more common in women. The initial symptoms of facial muscle spasm are mostly “eyelid fluttering”, which is different from the eyelid fluttering of “left eye jumping for money, right eye jumping for disaster”. The eyelid twitching is usually limited to the upper or lower eyelid on one side, while the eyelid twitching in facial myospasm is often simultaneous with the upper and lower eyelids on one side, especially with the ipsilateral corner of the eye “jumping”.
Facial myoclonus symptoms are likely to occur when nervousness is present. It can also occur in a quiet state, and the spasm resolves after a few minutes. The frequency and intensity of “eyelid fluttering” gradually increases, and after a period of time, it develops into twitching of the facial muscles on one side, including twitching around the eyes, corners of the mouth and cheeks. In more severe cases, the twitching of the neck muscles on one side and tinnitus on the other side may be associated with the twitching. At the end, a few cases may develop mild facial paralysis.
Etiology
Facial spasm is caused by abnormal impulses of the facial nerve due to pathological stimulation of certain parts of the facial nerve on one side.
In 1967, Jannette proposed that microvascular compression of the root of the facial nerve (near the area just out of the brainstem, which is known as the REZ zone) is the main cause of facial muscle spasm. This theory is now widely accepted. The microvessels that compress the facial nerve root and cause facial muscle spasm symptoms are medically referred to as the responsible vessels. The majority of the responsible vessels are small arteries, one or several of which are sclerotic and twisted, compressing the facial nerve root. Occasionally, the responsible vessel is also a vein.
Other causes of facial muscle spasm are rare, such as tumor, inflammation, demyelination after facial neuritis, etc.
Three, treatment methods
1, symptom control methods: Botox injection treatment. Radical method: craniotomy microvascular decompression surgery. Chinese medicine (medicine, acupuncture) treatment: ineffective.
2.Botulinum toxin injection treatment
Botulinum toxin needle, medically called botulinum toxin A. Botulinum toxin needle is injected locally in the affected face, paralyzing the nerves of the face, interfering with the transmission of nerve signals from the facial nerve unpoints, so that the facial muscle fibers cannot contract causing artificial light facial paralysis, so it can control the symptoms of facial muscle spasm.
Botox injections need to be repeated several times. After receiving Botox injection treatment, more than 90% of patients’ symptoms will be significantly improved, generally the effect will start after 3 days of medication, and the effect will gradually disappear after 3-6 months, and facial twitching will recur, so repeated injection is needed after 3-6 months to maintain the effect. Prolonged injections will produce drug resistance and decrease the efficacy.
Botox injections are relatively safe, and complications are rare. Occasional complications include ptosis, dry eye, and mild facial paralysis on the side of the injection, but these symptoms often fade after 1 to 6 weeks. After botulinum toxin injection, some patients’ facial twitching has been reduced or disappeared externally, but the patient feels that the facial muscles are still twitching constantly inside and still feels uncomfortable. Patients who have been injected for a long time will have more or less symptoms of facial paralysis.
In addition, it should be reminded that botulinum toxin injections for facial muscle spasms must be done by a professional doctor (neurologist, etc.) in a regular hospital. This is because strict injection sites and doses are the key to ensuring efficacy and minimizing post-injection complications.
3.Surgical treatment (cranial microvascular decompression surgery)
Open microvascular decompression surgery is a radical treatment for the cause of facial muscle spasm. Since the 1980s, this method has become the preferred treatment for facial spasm, with a complete cure rate of about 90% to 95% and a recurrence rate of only about 5%.
The specific method is: performed under general anesthesia. A 3 cm diameter bone hole is drilled and milled behind the affected ear (a small bone flap is backfilled at the end of surgery), the facial nerve root is exposed under the operating microscope, the arachnoid membrane here is fully loosened, the blood vessels compressing the facial nerve root are found and then freed, and a Teflon cotton wool mass is padded between the blood vessels and the nerve.
The postoperative myospasm will stop immediately or gradually. The fact that facial muscle spasm is still present after surgery does not mean that the treatment is ineffective. Although open microvascular decompression surgery relieves the vascular compression of the facial nerve, it takes some time for the myelin sheath of the facial nerve root to regenerate and repair and for the excitability of the motor nucleus of the facial nerve to stabilize. Cases that still have facial muscle twitching after surgery should be observed patiently for about 6 months. If facial twitching is still present after 6 months, the surgery can be judged as ineffective.
This surgery requires a more advanced neurosurgical microscope and surgical instruments, and requires more skillful microsurgery skills of the surgeon. It usually requires about 1 week of hospitalization.
In conclusion, botulinum toxin injection treatment can be considered to control the symptoms in the early stage of the disease (especially in elderly patients); in the long stage of the disease, especially in young patients with high cosmetic requirements, it is advisable to receive open microvascular decompression surgery to cure the disease.
IV. Differential diagnosis
It is necessary to distinguish facial twitching caused by other reasons (other than compression of blood vessels in the root of facial nerve). Because these causes of “facial twitching” are not effective in cranial microvascular decompression surgery, other methods of treatment are needed.
1.Megei’s syndrome
Megei’s syndrome is mainly characterized by bilateral eyelid spasms and symmetrical involuntary facial movements. The onset of Megei’s syndrome is usually slow, with a sense of irritation or discomfort in one or both eyes, shame, increased blinking frequency, and dry eyes before developing into blepharospasm. Meige’s syndrome is characterized by a dramatic reduction in symptoms when yawning, eating, coughing, or singing (Tricks phenomenon). The etiology of Meige syndrome is unknown and may be related to hypofunction of nigrostriatal γ-aminobutyric acidergic neurons in the basal ganglia of the brain.
The preferred treatment for Meige syndrome is medication, and if medication is not effective, some patients may be treated with botulinum toxin, and if these treatments are not effective, deep brain stimulation may be considered.
Oral medications include.
(1) dopamine receptor antagonists, such as haloperidol, Tebri, etc;
(2) γ-aminobutyric acid drugs, such as Gaglodin, sodium valproate, etc;
(3) Anticholinergics, such as Antan, etc;
(4) Valium, such as Valium, Clonidine, etc.;
(5) antidepressants, such as amitriptyline, etc.
2.Facial twitching after facial palsy
Facial muscle twitching produced by the sequelae of facial palsy is usually produced only when doing actions such as blinking and raising eyebrows. Generally no special treatment is needed, and severe cases can try botulinum toxin injection treatment on the affected face.