Myoclonus refers to a quick, involuntary muscle jerk. For example, hiccups are a form of myoclonus. So are the sudden jerks, or "sleep starts," you may experience just before falling asleep. These forms of myoclonus occur in healthy people and rarely present a problem.

Most often, myoclonus occurs as a result of a nervous system (neurological) disorder, such as epilepsy, or of a metabolic condition, or as a reaction to a medication.

Ideally, treating the underlying cause will help control your myoclonus symptoms. If the cause of myoclonus is unknown or can't be specifically treated, then treatment focuses on reducing the effects of myoclonus on your quality of life.

Symptoms Causes

People with myoclonus often describe their signs and symptoms as jerks, shakes or spasms that are:

  • Sudden
  • Brief
  • Involuntary
  • Shock-like
  • Variable in intensity and frequency
  • Localized to one part of the body or all over the body
  • Sometimes severe enough to interfere with eating, speaking or walking

When to see a doctor

If your myoclonus symptoms become frequent and persistent, talk to your doctor for further evaluation and proper diagnosis and treatment.

© 1998-2015 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. Terms of use