Hemifacial spasm is a relatively painless neurological condition in which the muscles of one side of the face spasm uncontrollably.
It is usually caused by the loop of a blood vessel compressing or irritating the facial nerve as it leaves the brainstem. Occasionally it can be associated with a tumour or aneurysm.
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WHAT ARE THE SYMPTOMS OF HEMIFACIAL SPASM?
Hemifacial spasm tends to occur in middle age and in the elderly. The muscles on one side of the face contract episodically, often in response to talking or chewing. There is often a degree of facial weakness in between spasms. Social embarrassment frequently results.
The main differential diagnosis is blepharospasm, which only affects the muscles around the eye and is usually bilateral.
HOW IS HEMIFACIAL SPASM DIAGNOSED?
In most cases, the diagnosis can be made on the basis of symptoms and neurological examination findings. EMG, or electromyography, may be of assistance in making the diagnosis.
HOW IS HEMIFACIAL SPASM TREATED?
Mild cases of hemifacial spasm do not require specific treatment. Botox has been used with success, however the injections generally need to be repeated.
Surgery, in the form of a posterior fossa craniotomy and microvascular decompression, has a high success rate. This involves placing a small Teflon pad between the offending blood vessel and the facial nerve. It does carry risks, including facial weakness, deafness, and stroke, and should not be undertaken lightly.