Overview

Hemifacial spasm is a nervous system condition that causes muscles on one side of the face to twitch or spasm. You cannot control hemifacial spasms. They usually start around one eye and may spread on that side of the face. The most common cause is a blood vessel pressing on the facial nerve. Sometimes there is no known cause. While hemifacial spasms are not life-threatening, they can be uncomfortable and affect social interaction.

Symptoms

Hemifacial spasms also are called muscle movements or contractions. These spasms often start in one eyelid. They might move to the cheek and mouth on the same side of the face. First, hemifacial spasms come and go. But over months to years, they occur almost all the time. How quickly they spread and how often they happen may be different for everyone.

Common symptoms of hemifacial spasm are usually painless but may include muscle movements:

  • On one side of the face.
  • That cannot be controlled.
  • That spread from the eye area to other areas on the same side of the face.
  • That happen more often over time.
  • That happen while you are sleeping.

Sometimes, hemifacial spasms occur on both sides of the face. However, they don't often occur on both sides of the face at the same time.

Certain things can increase hemifacial spasm symptoms, such as:

  • Moving the muscles in the face.
  • Anxiety.
  • Stress.
  • Being tired.

Causes

The most common cause of hemifacial spasms is a blood vessel touching a facial nerve. A tumor pressing against a facial nerve or a facial nerve injury also may cause them. Sometimes the cause isn't known.

Risk factors

Some studies show that these factors may increase the risk of hemifacial spasm:

  • High blood pressure, also called hypertension.
  • Age older than 40.
  • Being assigned female at birth.
  • Certain genes that give instructions to proteins that help carry cholesterol and other fats through the bloodstream, such as APOE e4.
  • Brain lesions or tumors, or conditions such as multiple sclerosis.
  • History of facial nerve injury or Bell's palsy.

Prevention

There is no known way to prevent hemifacial spasm. But managing stress, fatigue and anxiety may help lessen symptoms.

By Mayo Clinic Staff