Acute Flaccid Myelitis (AFM)

What You Should Know About Acute Flaccid Myelitis (AFM)

Acute flaccid myelitis is a rare but serious condition that affects the nervous system. It was first discovered in 2014. Acute Flaccid Myelitis mostly occurs in young children and targets the gray matter in the spinal cord, making muscles and reflexes in one or more limbs weak. This weakness happens quickly, often affects one side of the body more than the other and can lead to paralysis.

Acute Flaccid Myelitis is similar to polio because both affect the spinal cord's gray matter and cause floppy limb weakness. In some cases, the weakness may lead to permanent paralysis. However, the polio virus has not been found in people diagnosed with Acute Flaccid Myelitis.

What Are the Symptoms?

Acute Flaccid Myelitis symptoms appear suddenly, often within a few hours to days. These include:

  • Weakness in one or more arms or legs
  • Loss of muscle tone
  • Weakened or absent reflexes

One to two weeks before developing these symptoms, most patients had a mild respiratory illness with a runny nose, cough, or fever. Other symptoms can include:

  • Pain in arms or legs, neck, or back
  • Facial drooping or weakness
  • Drooping eyelids
  • Difficulty swallowing or slurred speech

Severe cases may lead to respiratory failure, body temperature changes, and blood pressure instability, which can be life-threatening.

How is Acute Flaccid Myelitis Diagnosed?

Acute Flaccid Myelitis can be difficult to diagnose because its symptoms are similar to other neurologic diseases. A healthcare provider will review the patient's medical history, perform a physical exam, and may order:

  • Testing of cerebrospinal fluid, respiratory fluid, blood, and stool
  • MRI of the brain and spine

How is Acute Flaccid Myelitis Treated?

Patients with Acute Flaccid Myelitis are cared for in the hospital where healthcare providers monitor their condition. Treatment focuses on reducing spinal cord inflammation, managing symptoms, and preventing complications.

Some patients see improvements in muscle function over time. A few fully recover, often around 4 months after symptoms begin. However, some patients do not improve and remain weak or paralyzed.

What Causes Acute Flaccid Myelitis?

The exact cause of Acute Flaccid Myelitis is still unknown. Most patients had mild respiratory or gastrointestinal (stomach) symptoms, or a fever, 1-2 weeks before their limb weakness started. This may suggest a viral infection. Non-polio enteroviruses, such as enterovirus D-68, are thought to be linked to Acute Flaccid Myelitis.

Is There a Vaccine for Acute Flaccid Myelitis?

There is no vaccine or medicine that can prevent Acute Flaccid Myelitis.

How Can You Prevent Acute Flaccid Myelitis?

Though we don't know exactly why some people develop Acute Flaccid Myelitis after having a virus, you can reduce your risk by taking these steps: