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Hemifacial Spasm

ByMichael Rubin, MDCM, New York Presbyterian Hospital-Cornell Medical Center
Reviewed/Revised Modified Aug 2025
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Hemifacial spasm is painless involuntary twitching of 1 side of the face due to malfunction of the seventh cranial (facial) nerve and/or the area of the brain that controls it (called a center or nucleus). The seventh cranial nerve moves the facial muscles, stimulates the salivary and tear glands, enables the front two-thirds of the tongue to detect tastes, and controls a muscle involved in hearing.

  • Twitching may occur only occasionally at first but may become almost constant.

  • Doctors diagnose hemifacial spasm based on symptoms but do magnetic resonance imaging to check for other disorders that can cause similar symptoms.

  • Hemifacial spasm is treated with botulinum toxin or another medication, but if medications are ineffective, surgery may be necessary.

Hemifacial spasm affects men and women but is more common among middle-aged and older women.

The spasms may be caused by

  • An abnormally positioned artery or loop of an artery that puts pressure on (compresses) the facial cranial nerve where it exits the brain stem

Symptoms of Hemifacial Spasm

Muscles on 1 side of the face twitch involuntarily, usually beginning with the eyelid, then spreading to the cheek and mouth. Twitching may be intermittent at first but may become almost continuous.

Hemifacial spasm is essentially painless but can be embarrassing and look like a seizure.

Diagnosis of Hemifacial Spasm

  • A doctor's evaluation

  • Magnetic resonance imaging

Hemifacial spasm is diagnosed when doctors see the spasms.

Magnetic resonance imaging (MRI) should be done to rule out tumors, other structural abnormalities, and multiple sclerosis, which can cause similar symptoms. Also, MRI can usually detect the abnormal loop of artery pressing against the nerve.

Treatment of Hemifacial Spasm

  • Botulinum toxin

  • Sometimes surgery

Botulinum toxin (used to paralyze muscles or to treat wrinkles) is the medication of choice for hemifacial spasm. It is injected into the affected muscles. The same medications used to treat trigeminal neuralgiacarbamazepine, gabapentin, phenytoin, baclofen, and —carbamazepine, gabapentin, phenytoin, baclofen, andtricyclic antidepressants—can also be used.

If medications are unsuccessful, surgery (called vascular decompression) may be done to separate an abnormal artery, if present, from the nerve by placing a small sponge between them.

Drugs Mentioned In This Article

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