Acute flaccid myelitis (AFM)


Acute flaccid myelitis (AFM) is an uncommon and serious disease that targets the spinal cord, causing a sudden onset of weakened muscles, loss of reflexes, and reduced muscle tone. The condition primarily impacts young children, and it can be life-threatening.

The initial description of AFM was made by researchers in 2014. Before, medical professionals and researchers believed it to be a form of transverse myelitis.

Your spinal cord’s gray matter becomes inflamed because of AFM. Your central nervous system, which includes your brain and spinal cord, contains gray matter. Gray matter is a crucial component of the central nervous system, and it plays a vital role in enabling you to perform daily activities smoothly. Specifically, in your spinal cord, gray matter is responsible for regulating movement and coordinating muscle function.

Before experiencing symptoms of acute flaccid myelitis, the majority of children experience a mild respiratory illness or fever brought on by a viral infection one to four weeks earlier.

If you or your child start experiencing symptoms of acute flaccid myelitis, it is important to seek prompt medical attention as the condition can progress rapidly. Hospitalization may be necessary, and in some cases, a ventilator might be required to provide breathing support.


The following are some of the most typical sudden acute flaccid myelitis signs and symptoms:

  • Weakness of the arm and leg
  • Muscular tone decline
  • Diminished reflexes
  • Loss of balance and coordination

Additional warning signs and symptoms could be:

  • Slurred speech or trouble swallowing
  • Neck, back or arms pain
  • Drooping eyelids or trouble with eye movements
  • Facial droopiness or weak face

Some unusual symptoms could be:

  • Dysfunction of bladder and bowel
  • Tingling or no sensation or numbness

Respiratory failure is one of the more severe symptoms, caused by the weakening of the breathing muscles. Additionally, blood pressure instability and potentially fatal changes in body temperature are possible.

If you or your child exhibits any of the above-mentioned symptoms or signs, you should consult a doctor right away.


Acute flaccid myelitis is thought to be caused by a viral infection, specifically an enterovirus. While most people who contract enteroviruses recover without issue, some individuals, particularly children, may develop acute flaccid myelitis. The exact reasons why some individuals are more susceptible to developing this condition remain unclear.
The symptoms of acute flaccid myelitis can be similar to those of poliovirus disease, which can cause weakness and paralysis in the limbs.

Risk factors

Acute flaccid myelitis predominantly affects young children, however, adults may also experience the condition.