Before we begin: Acute flaccid myelitis (AFM) is a rare but serious neurologic disease. It mostly affects children. Learn about its possible causes and symptoms.
This tutorial walks you through everything you need to know about acute flaccid myelitis. We explain it in plain language, step by step, so whether you are a student, a patient, or simply curious, you will come away with a solid understanding.
We cover what it is, why it matters, how it is diagnosed, and what you can do about it. Key facts are called out along the way.
What is acute flaccid myelitis (AFM)? Acute flaccid myelitis (AFM) is a neurologic disease. It is rare, but serious. It affects an area of the spinal cord called gray matter. This can cause the muscles and reflexes in the body to become weak.
Because of these symptoms, some people call AFM a “polio-like” illness. But it is different from polio. AFM is not caused by polioviruses.
What causes acute flaccid myelitis (AFM)? AFM can be caused by several different viruses. Researchers think that enteroviruses have been causing the recent increases in the number of children with AFM. AFM can also be caused by other viruses, including flaviviruses, herpesviruses, and adenoviruses.
Most people with AFM had a mild respiratory illness or fever (like you would get from a viral infection) before they got AFM.
Who is more likely to develop acute flaccid myelitis (AFM)? Anyone can get AFM, but most cases (more than 90%) have been in young children.
What are the symptoms of acute flaccid myelitis (AFM)? Most people with AFM will suddenly have:
Arm or leg weakness
A loss of muscle tone and reflexes
Some people also have other symptoms, including:
Facial drooping/weakness
Trouble moving the eyes
Drooping eyelids
Trouble swallowing
Slurred speech
Pain in the arms, legs, back, or neck
Sometimes AFM can weaken the muscles that you need for breathing. This can lead to respiratory failure, which is very serious. If you get respiratory failure, you may need to use a ventilator (breathing machine) to help you breathe.
If you or your child develops any of these symptoms, get medical care right away.
How is acute flaccid myelitis (AFM) diagnosed? AFM causes many of the same symptoms as other neurologic diseases, such as transverse myelitis and Guillain-Barre syndrome. This can make it difficult to diagnose. To find out if you have AFM, your doctor may use:
A neurologic exam, including looking at where there is weakness, poor muscle tone, and decreased reflexes
An MRI to look at the spinal cord and brain
Lab tests on the cerebrospinal fluid (the fluid around the brain and spinal cord)
Nerve conduction and electromyography (EMG) studies. These tests check nerve speed and the response of muscles to the messages from the nerves.
It is important that the tests are done as soon as possible after the symptoms start.
What are the treatments for acute flaccid myelitis (AFM)? There is no specific treatment for AFM. A doctor who specializes in treating brain and spinal cord illnesses (neurologist) may recommend treatments for specific symptoms. For example, physical and/or occupational therapy may help with arm or leg weakness. Researchers do not know the long-term outcomes of people who get AFM.
Can acute flaccid myelitis (AFM) be prevented? There is no specific way to prevent AFM. But you can take steps to prevent getting sick from a virus by:
Washing your hands often with soap and water
Avoiding touching your face with unwashed hands
Avoiding close contact with people who are sick
Cleaning and disinfecting surfaces that you frequently touch, including toys
Covering coughs and sneezes with a tissue or upper shirt sleeve, not hands
Staying home when sick
Centers for Disease Control and Prevention
Also known as: AFM.
Categories: Children and Teenagers, Infections, Brain and Nerves.
Source: National Institutes of Health — National Institute of Neurological Disorders and Stroke.
Key Takeaways
Understanding acute flaccid myelitis is an important part of taking charge of your health. Here is what to remember:
- Know the signs — Recognizing early symptoms can lead to earlier diagnosis and better outcomes.
- Talk to your provider — If you have concerns or a family history of this condition, bring it up at your next checkup.
- Stay informed — Medical knowledge evolves. Keep learning and asking questions.
- You are not alone — Many people deal with this condition. Support groups and educational resources can help.