About Acute Flaccid Myelitis (AFM)

Acute flaccid myelitis (AFM) is a rare but serious condition affecting the nervous system, specifically the spinal cord. AFM causes weakness in the body’s muscles and reflexes.

Signs and Symptoms

AFM causes sudden arm and/or leg weakness. AFM also causes loss of muscle tone and reflexes. Someone with AFM might also have:   

  • facial droop/weakness  
  • difficulty moving the eyes  
  • drooping eyelids  
  • difficulty with swallowing or slurred speech  
  • pain in the arms or legs  

Rarely, someone with AFM might have numbness or tingling in limbs, and difficulty passing urine. Some patients might have difficulty breathing due to muscle weakness and need ventilator support. AFM can also cause severe neurologic complications.

If you see potential symptoms of AFM in your child, (for example, if he or she is not using an arm), contact your health care provider right away.   


AFM can be diagnosed by examining your child’s nervous system, taking an MRI scan, testing the cerebral spinal fluid, and checking nerve conduction. It is important that tests are done as soon as possible after someone develops symptoms.  

While there is no specific treatment for AFM, doctors may recommend certain interventions on a case-by-case basis.  


There is no known single cause of AFM, but the U.S. Centers for Disease Control and Prevention (CDC) believes viruses, including enteroviruses, might be associated with AFM.    

In the U.S., most patients with AFM occurring since 2014 had signs of a viral illness (ex: runny nose, fever, cough), just before their AFM onset.    

Sometimes, the cause of a patient’s AFM may not be identified.  


There is no single, specific cause of AFM. However, since AFM can develop after a viral infection, The Georgia Department of Public Health recommends parents and children take basic steps to avoid infections and stay healthy including:   

  • making sure you and your family are up to date on your vaccinations,  
  • protecting yourself from insect bites, and  
  • washing your hands often.  

Additional Resources 

Page last updated 12/22/2022