Acute Flaccid Myelitis

Illustration of the brain on a blue background

Acute flaccid myelitis (AFM) is also called “acute flaccid paralysis with anterior myelitis” or “polio-like syndrome.” It is rare and mainly found in children. It affects the body’s nervous system, specifically the spinal cord. AFM can be caused by some viruses, environmental toxins, and genetic disorders.

Viruses that can cause AFM include enteroviruses (polio and non-polio) and flaviviruses such as West Nile Virus, Japanese Encephalitis virus, or St. Louis encephalitis virus. Other viruses that may cause AFM are herpesviruses (such as cytomegalovirus and Epstein-Barr virus) and adenoviruses.

While AFM can cause your arms or legs to become weak, genetic disorders, environmental toxins, and Guillain-Barré syndrome can cause similar symptoms. Even with testing, sometimes the cause of AFM is never found.

About AFM

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Last revised January 7, 2025