Acute Flaccid Myelitis (AFM): Symptoms & Signs

Medically Reviewed on 1/22/2020

Acute flaccid myelitis is a rare condition that causes muscle weakness and decreased reflexes in the body. Less than 1 out of 1 million people develop this rare condition each year.

Signs and symptoms of acute flaccid myelitis include arm or leg weakness that comes on suddenly, accompanied by loss of muscle tone and reflexes. Other associated symptoms can include

Respiratory failure is the most serious potential symptom.

Cause of acute flaccid myelitis

The exact cause of acute flaccid myelitis is often unknown, but medical professionals have reported toxins, viruses, and genetic disorders as possible causes of acute flaccid myelitis. Viruses that may cause the condition include poliovirus, non-polio enteroviruses, adenoviruses, or the West Nile virus.

Other acute flaccid myelitis (afm) symptoms and signs

  • Arm or Leg Weakness That Comes on Suddenly
  • Difficulty Moving the Eyes
  • Drooping Eyelids
  • Facial Droop
  • Facial Weakness
  • Loss of Muscle Tone and Reflexes
  • Problems With Swallowing
  • Respiratory Failure
  • Slurred Speech

Jameson, J. Larry, et al. Harrison's Principles of Internal Medicine, 20th Ed. New York: McGraw-Hill Education, 2018.