What is acute flaccid myelitis (AFM) in children?

AFM is a rare condition that affects the nervous system. It damages the spinal cord, leading to muscle weakness and reflex problems. Its symptoms start suddenly and may cause paralysis in the arms or legs. In some cases, AFM can be life-threatening if it affects the muscles that control breathing or swallowing.

AFM mostly affects children. Those who get it are often sick with a flu or cold-like illness before they develop AFM.

What causes AFM in a child?

The exact cause of AFM is unknown. Ongoing research suggests it may be linked to a certain type of virus called an enterovirus. This kind of virus can cause a respiratory illness. Many children who have gotten AFM were infected with an enterovirus beforehand. But many more children who were infected with such a virus did not develop AFM. It’s unclear why some children get AFM but not others.

Which children are at risk for AFM?

Children who become infected with an enterovirus seem more at risk for AFM.

What are the symptoms of AFM in a child?

The symptoms of AFM can vary from child to child. They can range from mild to severe. They often start suddenly within a week or so after recovering from a flu or cold-like illness. Symptoms of AFM may include:

• Sudden weakness, often in an arm or leg

• Poor muscle tone and reflexes

• Pain in the arms, legs, neck, or back

• Weakness in the face that can cause problems swallowing, breathing, or speaking

• Trouble moving the eyes or droopy eyelids

• Problems controlling the bladder or bowel

Symptoms can worsen quickly and become life-threatening. So if your child has any of the symptoms above, get medical care right away.

The symptoms of AFM can look like other health problems. Make sure your child sees a healthcare provider for a diagnosis.

How is AFM in a child diagnosed?

To diagnose AFM, a healthcare provider will ask about your child’s symptoms and health history. They'll also give your child a physical exam.

Your child will need some tests. These may include:

• MRI of the spine. This imaging test can show if there is any damage to the spinal cord.

• Lumbar puncture. During this test, a needle is put into the lower back to take a sample of cerebrospinal fluid. The fluid is then checked for infection.

• Nerve conduction study. This test checks how well the nerves are working.

• Electromyography. This test checks how well the muscles are responding to the nerves.

• Other tests. Your child’s healthcare provider may order other tests, such as blood work, a nasal swab, or fecal testing. These can help confirm an enterovirus infection. Or they can help rule out other possible causes of your child’s symptoms.

How is AFM in a child treated?

The symptoms of AFM can get worse quickly, so your child will get treatment in a hospital. While there, your child will be watched for any serious symptoms like trouble breathing.

There is no specific treatment or medicine for AFM. Your child may get:

• Supportive care. This may include medicine for pain or other treatments to ease certain symptoms. If your child has trouble breathing, they may be given oxygen or put on a ventilator to help them breathe.

• Other treatments. In some cases, your child’s provider may advise treatments such as steroids, intravenous immunoglobulin, or therapeutic plasma exchange. But experts are still studying how well these treatments work.

• Rehabilitation. Once your child is on the mend, your child’s healthcare provider may advise physical and occupational therapy. This can help with muscle weakness and movement problems.

• Tendon or nerve transfer surgery. Some children who have serious muscle weakness may benefit from this type of surgery. It involves moving healthy nerves or tendons to places in the body where nerves or tendons have died.

Talk with your child’s providers about the risks, benefits, and possible side effects of all treatments.

What are possible complications of AFM in a child?

Possible complications can vary from child to child. They may include:

• Long-term muscle weakness in the limbs

• Ongoing trouble breathing in severe cases

• Nerve pain

• Joint and muscle problems

• Anxiety

• Depression

• Death

How can I help prevent AFM in my child?

You can help prevent AFM in your child by lowering their risk of getting infected with a virus. To do so:

• Make sure your child washes their hands well and often. Teach them to wash their hands with soap and clean, running water for at least 20 seconds.

• Teach your child not to touch their face with unclean hands.

• Keep your child away from people who are sick. And have them stay home when they aren’t feeling well.

• Regularly disinfect high-touch surfaces like doorknobs or cell phones.

• Make sure your child covers their nose and mouth with a tissue when sneezing or coughing.

• Don’t let your child share utensils or cups with other people.

How can I help my child live with AFM?

Your child may have long-term problems like muscle weakness from AFM. Physical and occupational therapy is key in helping your child manage these problems. If your child has trouble moving, they may also benefit from using orthotic or assistive devices. Work closely with your child’s care team, including a neurologist and physical therapist, to address your child’s needs.

When should I call my child's healthcare provider?

Call your child’s healthcare provider right away if your child has:

• Symptoms that don’t get better or get worse

• New symptoms

Key points about acute flaccid myelitis in children

• AFM is a rare condition that affects the nervous system. It damages the spinal cord, leading to muscle weakness and reflex problems.

• AFM may be linked to a certain type of virus called an enterovirus.

• The main symptoms of AFM include sudden weakness in a limb and poor muscle tone and reflexes.

• Tests that can help diagnose AFM include MRI, lumbar puncture, and studies to check how well the nerves and muscles are working.

• There is no specific treatment or medicine for AFM. Your child will receive supportive care.

• AFM can cause lasting muscle weakness. Physical and occupational therapy can help.

Next steps

Tips to help you get the most from a visit to your child’s healthcare provider:

• Know the reason for the visit and what you want to happen.

• Before your visit, write down questions you want answered.

• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.

• Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.

• Ask if your child’s condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if your child does not take the medicine or have the test or procedure.

• If your child has a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your child’s provider after office hours. This is important if your child becomes ill and you have questions or need advice.