Skip all navigation Skip to page navigation

DHHS Home | A-Z Site Map | Divisions | About Us | Contacts

NC Department of Health and Human Services
NC Division of Public Health
N.C. Public Health Home

Diseases & Topics

Acute Flaccid Myelitis (AFM)

View Memo to Healthcare Providers (PDF, 317 KB) - Updated 09/20/2022

Acute flaccid myelitis (AFM) is a condition that affects the nervous system, specifically the spinal cord, which can result from a variety of causes including viral infections. AFM is characterized by a sudden weakness in one or more arms or legs, along with loss of muscle tone and decreased or absent reflexes. Numbness or other physical symptoms are rare, although some patients may have pain in their arms or legs. In some cases, dysfunction of the nerves controlling the head and neck, resulting in such features as facial weakness, difficulty swallowing, or drooping of the eyelids, may accompany the limb weakness.

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, to help differentiate such patients from patients with other forms of acute flaccid paralysis (AFP). Magnetic resonance imaging (MRI) can be very helpful in diagnosing cases of AFM.

Testing nerve response can also be helpful in supporting a diagnosis of AFM; it is important that the tests are performed at the appropriate time (e.g., 7-10 days after onset of weakness) to be helpful. Finally, by testing the cerebrospinal fluid (CSF, the fluid bathing the brain and spinal cord), clinicians can look for findings suggestive of AFM. All of these findings put together help a clinician make a diagnosis of AFM.

There is no specific treatment for acute flaccid myelitis, but a doctor who specializes in treating brain and spinal cord illnesses (neurologist) may recommend certain interventions on a case-by-case basis.

If you or your child is having problems walking or standing, or develop sudden weakness in an arm or leg, you should contact a doctor right away.

For Additional Information