Hemifacial spasm is a disorder affecting the nerve from the brain that controls the muscle on one side of the face. It causes very rapid, involuntary twitching of the facial muscles on the affected side only. There is no warning. In this article, the symptoms, causes and treatment of hemifacial spasm are discussed.
It is also more common in women compared to men.
- Initially, the spasm starts gradually. Most commonly, it affects the muscles around the eye and appears like a persistent eye twitch.
- Over time, the spasm spread to the lower muscles of the face on the same side including the cheek, jaw, chin, and neck.
- The symptoms are also worse during times of emotional stress. They can also be triggered by moving the face or during activity such as eating.
- Eventually, the spasms may become continuous and affect all the muscles of the face on the one side and can be disabling.
- Patients not able to see on that side due to the involuntary closure of the eye.
- Speech may also be affected.
- Less commonly, there may be a ringing sound in the ear.
Find out how to estimate severity using our calculator: Hemifacial Spasm Grading Scale
What is the prognosis of hemifacial spasm?
- Without treatment, hemifacial spasm generally tends to be a long-term condition with significant impact on quality of life.
- It rarely improves completely without treatment.
- Treatment has to be individualised to the patient depending on the cause, severity, and response to treatment.
It is most often caused by a blood vessel pressing on the facial nerve as it leaves the brain. Other causes are nerve injury or tumour. Sometimes, no cause can be found.
This is similar to the cause of Trigeminal Neuralgia, another condition caused by abnormal pressure from a blood vessel on the cranial nerve.
- History and neurological examination
- MRI scan to look for blood vessel compressing the nerve and to look for any tumour compressing the nerve
- Electromyogram may occasionally also necessary to rule out other conditions
- Hemifacial spasm should be differentiated from other conditions such as blepharospasm (where both eyelids are affected)
Treatment of hemifacial spasm
1. Medication is not considered to be effective
Hemifacial spasm is initially treated with oral medications or injection of botulinum toxin type A.
- The oral medications used are baclofen, clonazepam, and carbamazepine. Unfortunately, drugs very often do not work well in this condition and is not considered a main treatment.
2. Injection is an effective treatment but needs to be regularly repeated
Botulinum treatment (botox) involves injecting small amounts of the toxin into the affected muscles usually around the eye and face. This can be effective and the effect lasts between 3-6 months. The injections will need to be repeated.
3. Microvascular decompression (MVD) is an effective treatment that is performed once
A common procedure used by our neurosurgeon to treat severe hemifacial spasm is microvascular decompression (illustrated in the figures). It is the most appropriate treatment for some patients, especially those who fail or cannot tolerate repeated botox injections. In this procedure, a small opening is made in the skull, and a piece of padding is placed between the facial nerve and the compressing blood vessel.
By releasing the irritation on the nerve, the root cause of the problem is immediately relieved. MVD can permanently resolve hemifacial spasm in most patients.
As this procedure is minimally invasive (keyhole surgery), the time to recovery is often short.
- Hemifacial spasms can lead to constant twitching of half the face which can be very uncomfortable and disabling especially as it becomes more noticeable and disruptive over time.
- If other modalities do not provide good relief, microvascular decompression (mvd) can be very effective in the treatment of hemifacial spasm.