by EBSCO Medical Review Board


Hemifacial spasm (HS) causes muscles to contract on one side of the face. A person cannot control the spasm.


HS does not always have a cause. It may be due to:

  • A blood vessel pressing on the facial nerve
  • Facial nerve injury
  • Tumor
Muscles of the Face
Muscles of the Face
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Risk Factors

HS is more common in older women. It is also more common in people who are Asian.


Problems may be:

  • Twitching of the eyelid muscle that causes the eye to close
  • A mouth that is pulled to one side
  • Spasms of all the muscles on one side of the face


The doctor will ask about your symptoms and health history. A physical exam will be done. It will focus on the face.

Images of the head may be taken. This can be done with:

Nerve and muscle function may be tested. This can be done with electromyography (EMG).


The goal of treatment is to ease pressure on the nerve. This can be done with:

  • Injections of botulinum toxin to temporarily stop spasms
  • Antiseizure medicine

Some people may need surgery to reposition a blood vessel that is pressing on a nerve.


There are no known guidelines to prevent this problem.


National Institute of Neurological Disorders and Stroke 

National Organization for Rare Disorders 


Canadian Movement Disorder Group 

Health Canada 


Chaudhry N, Srivrastava A, et al. Hemifacial spasm: the past, present, and future. J Neurol Sci. 2015;356(1-2):27-31.

Hemifacial spasm information page. National Institute of Neurological Disorders and Stroke website. Available at: Accessed October 14, 2020.

OnabotulinumtoxinA. EBSCO DynaMed website. Available at: . Accessed October 14, 2020.

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