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What Is Acute Flaccid Myelitis (AFM)?

Acute flaccid myelitis (AFM) is a rare but serious condition that affects the nervous system. AFM happens when swelling in the spinal cord causes the muscles and reflexes in the body to become weak. This condition is not new, but there has been an increase in reported cases since 2014. Most of the cases have been in children.


What Causes Acute Flaccid Myelitis (AFM)?

AFM is thought to be caused by infections with different types of viruses. The infections most commonly mentioned with AFM include polio or West Nile virus and related infections, though these are not always the cause. Most patients with AFM have a respiratory illness or fever before their limbs are affected. Oftentimes, despite extensive lab tests, the exact cause of AFM can’t be identified. Other causes of AFM are still being explored and might include environmental toxins and genetic disorders.

AFM is not contagious and can’t be spread from person to person, however, the viruses that are believed to cause AFM may be contagious from one person to another or may be spread by a mosquito or other ways, depending on which virus causes the AFM. These viruses can be avoided with proper and frequent hand washing, especially during cold and flu season, and covering coughs or sneezes.


Acute Flaccid Myelitis (AFM) Symptoms and Effects

Most children will have a sudden onset of arm or leg weakness and loss of muscle tone and reflexes. Some children, in addition to arm or leg weakness, will have:

  • Facial droop/weakness.
  • Difficulty moving the eyes.
  • Drooping eyelids, or difficulty with swallowing or slurred speech.
  • Numbness or tingling is rare in people with AFM, although some people have pain in their arms or legs. Some children who have AFM might be unable to pass urine (pee). The most severe symptom of AFM is respiratory failure that can happen when the muscles involved with breathing become weak. This can require urgent ventilator support (breathing machine).

If you or your child develops any of these symptoms, you should seek medical care right away.


Acute Flaccid Myelitis (AFM) Diagnosis and Treatment

A doctor can tell the difference between AFM and other diseases with a careful examination of the nervous system, looking at the location of the weakness, muscle tone, and reflexes. Magnetic resonance imaging (MRI) can be very helpful in diagnosing cases of AFM. Laboratory tests on biological specimens, including cerebrospinal fluid (CSF), might be needed to confirm the virus responsible for AFM.

Currently, there is no specific treatment or vaccine for AFM, but a doctor who specializes in treating brain and spinal cord illnesses (neurologist) might recommend certain treatments on a case-by-case basis. For example, neurologists might recommend physical or occupational therapy to help with arm or leg weakness caused by AFM.

Early physical and rehabilitative therapy for children who have AFM might be beneficial in preventing muscle loss, joint rigidity and might improve functional outcomes. Therapy exercises sometimes include electrical stimulation to spark nerves and muscles into action. Some children who have AFM undergo nerve transplants to regain lost mobility within 6-12 months after diagnosis.

Gillette offers comprehensive treatment for the symptoms of AFM, from rehabilitative therapy to nerve transplant surgery.


Integrated Care

If your child has AFM, our team of internationally recognized specialists will work closely with you to create a treatment plan that fits your unique needs. At Gillette, your child will receive care from one of the Twin Cities’ largest groups of pediatric rehabilitation medicine specialists. You might work with experts in other areas related to muscle disorders, including:

Testing and Diagnostic Services


Family Support

At Gillette, you won’t be left trying to figure out which services are best for your child. We’ll help you determine the specialties and services that will be most helpful to your family.