Acute flaccid myelitis is a rare condition that affects the nervous system. Inflammation of the gray matter in the spinal cord leads to muscle weakness and paralysis.

Acute flaccid myelitis (AFM) is usually caused by infection with a virus. While AFM is rare, there has been a slight increase in cases of AFM since 2014. Most new cases have occurred in children or young adults.

Causes

AFM usually occurs after a cold, fever, or gastrointestinal illness.

Different kinds of viruses may be the cause of AFM. These include:

• Enteroviruses (poliovirus and non-poliovirus)
• West Nile virus and similar viruses such as Japanese encephalitis virus and Saint Louis encephalitis virus
• Adenoviruses

It is unclear why certain viruses trigger AFM, or why some people develop the condition and others don't.

Environmental toxins also can cause AFM. In many cases, a cause is never found.

Symptoms

A fever or a respiratory illness is often present before weakness and other symptoms begin.

AFM symptoms often start with sudden muscle weakness and loss of reflexes in an arm or leg. Symptoms may progress rapidly over a few hours to days. Other symptoms may include:

• Facial droop or weakness
• Drooping eyelids
• Difficulty moving the eyes
• Slurred speech or difficulty swallowing

Some people may have:

• Stiffness in the neck
• Pain in the arms or legs
• Inability to pass urine

Severe symptoms include:

• Respiratory failure, when muscles involved in breathing become weak
• Serious nervous system problems, which may lead to death

Exams and Tests

Your health care provider will take your medical history and vaccination history to know if you are up-to-date with your polio vaccines. Unvaccinated individuals who are exposed to poliovirus are at higher risk for acute flaccid myelitis. Your provider also may want to know if within the last 4 weeks you have:

• Traveled
• Had a cold or the flu or a stomach bug
• Had a fever 100°F (38°C) or higher

Your provider will do a physical exam. Tests that may be done include:

• MRI of spine and MRI of the brain to view lesions in the gray matter

  MRI of spine

  A cervical MRI (magnetic resonance imaging) scan uses energy from strong magnets to create pictures of the part of the spine that runs through the ne...

  Read Article Now Book Mark Article

  MRI of the brain

  A head MRI (magnetic resonance imaging) is an imaging test that uses powerful magnets and radio waves to create pictures of the brain and surrounding...

  

  Image

  Read Article Now Book Mark Article
• Nerve conduction velocity test

  Nerve conduction velocity test

  Nerve conduction velocity (NCV) is a test to see how fast electrical signals move through a nerve. This test is done along with electromyography (EM...

  

  Image

  Read Article Now Book Mark Article
• Electromyography (EMG)

  Electromyography (EMG)

  Electromyography (EMG) is a test that checks the health of the muscles and the nerves that control the muscles.

  

  Image

  Read Article Now Book Mark Article
• Cerebrospinal fluid (CSF) analysis to check if white blood cells are elevated

  Cerebrospinal fluid (CSF) analysis

  Cerebrospinal fluid (CSF) analysis is a group of laboratory tests that measure chemicals in the cerebrospinal fluid. CSF is a clear fluid that surro...

  

  Image

  Read Article Now Book Mark Article

Your provider also may take stool, blood, and saliva samples to test.

Treatment

There is no specific treatment for AFM. You may be referred to a doctor specializing in disorders of the nerves and nervous system (neurologist). The doctor will likely treat your symptoms.

A number of medicines and treatments that work on the immune system have been tried but have not been found to help.

You may need physical therapy to help restore muscle function.

Outlook (Prognosis)

The long-term outlook of AFM is not known.

Possible Complications

Complications of AFM include:

• Muscle weakness and paralysis
• Loss of limb function

When to Contact a Medical Professional

Contact your provider right away if you or your child have:

• Sudden weakness in the arms or legs or difficulty moving the head or face
• Any other symptom of AFM

Prevention

There is no known way to prevent AFM. Having a polio vaccine may help reduce the risk of AFM related to the poliovirus.

Polio vaccine

All content below is taken in its entirety from the CDC Polio Vaccine Information Statement (VIS): www. cdc. gov/vaccines/hcp/vis/vis-statements/ipv....

Image

Read Article Now Book Mark Article

Take these steps to help avoid viral infections:

• Wash hands frequently with soap and water, especially before eating.
• Avoid close contact with people who have a viral infection.
• Use mosquito repellants when going outdoors to prevent mosquito bites.

To learn more and get recent updates, go to the CDC webpage about acute flaccid myelitis at www.cdc.gov/acute-flaccid-myelitis/index.html.

Disclaimer