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  • Cynthia M. Johnson, MA
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Myoclonus is a brief and rapid twitching of a muscle or group of muscles. It cannot be stopped or controlled.

There are many types. Some are normal, like hiccups. Other types are not normal, such as a reaction to a medicine. Myoclonus is a symptom not a disease.


The movements are caused by an unusual electrical signal in the nervous system. It starts in the brain, spinal cord, or nerves and travels to a muscle. It may be caused by:

  • A lack of oxygen or nutrients
  • Certain medicines or toxins
  • Problems of the nervous system
  • Metabolic disorders
  • Damage to the brain or spinal column
The Nervous System Pathways.

CNS and PNShttp://services.epnet.com/getimage.aspx?imageiid=72957295si2012.jpgsi2012.jpgNULLjpgsi2012.jpgNULL\\hgfiler01a\intellect\images\si2012.jpgNULL15NULL2008-11-072543907295_22481Copyright © Nucleus Medical Media, Inc.

Risk Factors

This problem is more common in people who have other family members with myoclonus. Other things that may raise the risk are:


Problems vary from person to person. A person will have jerking, twitching, or spasms that:

  • Range from mild to severe
  • Happen every once in a while or often
  • Affect one area of the body or the entire body
  • Happen at rest or during other movements

Mild forms may be a twitch followed by release, such as hiccups. Moderate forms may cause a shock-like spasm in muscle groups. Severe forms can make it hard to eat, speak, or walk.


The doctor will ask about symptoms and health history. A physical exam will be done. This is often enough to make the diagnosis.

Tests may be done to look for a cause. These may be:


The goal of treatment is to manage symptoms. How that is done depends on the cause.

Medicine that is causing myoclonus may be stopped or changed. Medicine may also be needed to reduce twitching. One of more of these may be used:

  • Sedatives
  • Antiseizure medicine
  • Dietary supplements
  • Adrenocorticotropic hormone (ACTH)


Myoclonus cannot always be prevented.





  • Eberhardt, O., and Topka, H. Myoclonic disorders. Brain Sci. 2017; 7 (8): E103.
  • Mikhaeil-Demo, Y., Gavvala, J.R., et al. Clinical classification of post anoxic myoclonic status. Resuscitation, 2017; 119: 76-80.
  • Myoclonus—approach to the patient. EBSCO DynaMed website. Available at: https://www.dynamed.com/approach-to/myoclonus-approach-to-the-patient.


  • Rimas Lukas, MD
Last Updated:

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.