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​Hemifacial Spasm (Facial Twitch)

What is Hemifacial Spasm?

Hemifacial spasm, also known as a facial twitch, is characterized by frequent involuntary twitching of one side of the face. This twitching or spasm usually starts around the eye and slowly progresses to involve the lower face. Muscles in the forehead and neck are usually the last to be affected.

UPMC neurosurgeons are among the most experienced in the U.S. in treating hemifacial spasm with microvascular decompression, which alleviates the spasms by moving the blood vessel away from the nerve.

Our doctors have refined this procedure since first implementing it nearly 40 years ago.

Today, UPMC neurosurgeons perform approximately 100 microvascular decompressions for hemifacial spasm each year, with 92 percent of people experiencing complete relief or dramatically improved symptoms. Surgery causes significant complications in fewer than 5 percent of cases.

Causes of hemifacial spasm

Several factors may cause hemifacial spasms:

  • A blood vessel pressing on a facial nerve
  • Injury to the facial nerve
  • Bell's Palsy
  • A tumor placing pressure on the facial nerve

The most common cause of hemifacial spasm is excessive pressure on the facial nerve by the anterior inferior cerebellar artery, where the nerve begins in your brainstem. This pressure causes the nerve to misfire and make your facial muscles contract and spasm.

Diagnosing Hemifacial Spasm

Your doctor will perform a physical exam and will ask about any symptoms you are having.

Hemifacial spasm symptoms

Symptoms may include:

  • An intermittent twitching in the eyelid muscle, which can lead to forced closure of the eye.
  • This spasm may gradually spread to the muscles of the lower face, which may cause the mouth to be pulled to one side.
  • In rare cases, doctors may see individuals with spasm on both sides of the face.

Hemifacial Spasm Treatment

Surgery is the preferred treatment for hemifacial spasm.

Microvascular decompression surgery

At UPMC, the treatment of choice for severe hemifacial spasm is microvascular decompression. Advances in instruments and techniques have made this treatment option more effective in recent years.

Microvascular decompression is a surgical procedure that relieves abnormal compression of a cranial nerve. The surgery consists of a linear incision behind the ear followed by a craniectomy (bony opening) the size of a silver dollar.

Under the view of a microscope or endoscope, the doctors detect the area where the blood vessel is affecting the nerve and then separate them, leaving a Teflon "pillow" in between.

During surgery, the doctors monitor facial nerve irritability to identify the blood vessel causing the nerve compression, making cure more likely. Monitoring also helps doctors to avoid damaging hearing and facial nerves.

Our neurosurgeons sometimes use endoscopes that allow them to look around corners as they operate, identify hidden blood vessels, and minimize the impact on sensitive brain tissue.