When a Facial Twitch Shouldn’t Be Ignored

Let’s say you’re about to ask your boss for a raise or you’ve been up all night with a crabby infant, and suddenly your eyelid begins to flutter or a cheek twitches involuntarily. These small spasms of the facial muscles are common — especially when under stress, sleep deprived or overly excited— and generally pass after a little rest and relaxation.

If, however, a facial twitch persists, gradually increases in frequency or intensity, and occurs on only one side of the face, it could be something more serious, called hemifacial spasm. This spasm, which typically begins with an eyelid, can become so intense the eyelid completely closes. As the spasm spreads to other parts of the face, your nose could begin to crinkle involuntarily or your mouth could pull to one side. Untreated, all the muscles on one side of your face eventually could twitch almost nonstop.

Hemifacial spasm is a chronic, progressive condition, and spontaneous recovery is rare. It occurs in about 10 in every 100,000 people. Anyone can develop a hemifacial spasm, but it is much more common among those of Asian descent and in middle-aged or older women.

What Causes Hemifacial Spasm?

Hemifacial spasms are a disorder of the facial nerve. The disorder is usually a primary condition — meaning there is no known underlying cause. Secondary hemifacial spasms are those that result from something else — an injury to the facial nerve or a tumor, for example. Other secondary causes include:

• A blood vessel pressing on the facial nerve where it exits the brain stem.
• Bell’s palsy, a condition that causes weakness on one side of the face. As the facial nerve regenerates, it may throw off some aberrant signals, causing twitches.
• Brainstem lesions such as those that form when a nerve’s myelin coating is attacked by the immune system as in multiple sclerosis.
• Malformations and abnormalities in blood vessels in the brain, including:
  • tangles of blood vessels (arteriovenous anomalies)
  • A weak or thin spot on an artery in the brain (intracranial aneurysm) that balloons or bulges
  • Abnormal connections between arteries and veins (arterio-venous fistula)
• Infections of the ear or the mastoid bone, located just behind the ear.
• Tumors in the salivary glands that sit just behind the ears.

Diagnosing Hemifacial Spasm

If you have symptoms of hemifacial spasm, you should see a neurologist because in most cases, the condition will not improve on its own. The doctor will take your medical history, conduct a physical exam and may order tests to confirm the diagnosis, including:

• A magnetic resonance image (MRI) of the brain that creates a detailed image by using magnetic field and radio wave
• A magnetic resonance angiogram that uses dye injected into a blood vessel to show whether the blood vessel is touching the facial nerve
• Electromyography, which stimulates a nerve, then measures muscle response or electrical activity to detect facial nerve lesions

How To Treat the Condition

For most patients, the standard treatment for hemifacial spasm is an injection of botulinum toxin into the affected area every three months. The purified form of this naturally occurring toxin temporarily prevents muscles from moving and is highly effective in controlling the spasms.

If a neurologist has determined the cause of hemifacial spasm is a blood vessel pressing on the facial nerve, the most likely treatment is a surgical procedure called microvascular decompression. In this operation, the surgeon lifts the blood vessel off the nerve and inserts a small Teflon pad to keep the two apart, relieving pressure on the facial nerve. While this procedure is considered safe and effective, post-surgical relief can be delayed as much as a year, and no surgery is without risk. Possible complications from microvascular decompression include a collection of fluid in the middle ear and hearing loss, both temporary.

While hemifacial spasm is not life-threatening, 90% of patients say it interferes with their social life, causing social isolation and depression and having a significant impact on the quality of life. For that reason alone, if you have persistent twitches on one side of the face should seek diagnosis and treatment.