Hemifacial spasm

Overview

Hemifacial spasm is a nervous system disorder in which the muscles on one side of your face twitch involuntarily. Hemifacial spasm is most often caused by a blood vessel touching or pulsating against a facial nerve. It may also be caused by a facial nerve injury or a tumor. Sometimes there is no known cause.

Symptoms

Common symptoms of hemifacial spasm include twitching or contracting of muscles in the face that are usually:

• On one side of the face
• Uncontrollable
• Painless

These contractions often start in the eyelid, then may progress and affect the cheek and mouth on the same side of the face. At first, hemifacial spasms come and go. But eventually, usually over the course of several months to a few years, they occur almost constantly.

Occasionally, hemifacial spasms may occur on both sides of the face. However, the twitching doesn't occur on both sides of the face at the same time.

Causes

Hemifacial spasm is most often caused by a blood vessel touching a facial nerve. It can also be caused by a facial nerve injury or a tumor. Sometimes there's no identifiable cause.

Hemifacial spasm may sometimes be triggered by:

• Moving the muscles in the face
• Anxiety
• Stress
• Fatigue