Hemifacial Spasm
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.
It is also more common in women compared to men. In rare instances, it can affect both sides of the face.
In this article, we will discuss about:
Symptoms of hemifacial spasm
- Patients are 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 (tinnitus) in the ear.
Estimate your severity
Try our Hemifacial Spasm Grading Scale
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.
Causes of hemifacial spasm
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.
Diagnosis of hemifacial spasm
- History and neurological examination
- Hemifacial spasm should be differentiated from other conditions such as blepharospasm (where both eyelids are affected)
- MRI scan is used 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
Treatment of hemifacial spasm
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 are not considered a main treatment.
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.
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 short. Additional advanced surgical techniques such as image guidance and intra-operative neuromonitoring further ensure safe and efficient surgery.
