©2018 WebMD, Inc. All rights reserved. eMedicineHealth does not provide medical advice, diagnosis or treatment. See Additional Information.

Symptoms and Signs of Acute Flaccid Myelitis (AFM)

Doctor's Notes on Acute Flaccid Myelitis (AFM)

Acute flaccid myelitis (AFM) is a rare disease of inflammation of the spinal cord, the part of the nervous system that carries messages to and from the brain. Most cases of acute flaccid myelitis occur in children, but the disease can occur in adults.

Symptoms of acute flaccid myelitis include sudden (acute) weakness in the arms or legs, along with loss of muscle tone and decreased or absent reflexes. Weakness may be mild to severe. Pain may also occur in some patients. Acute flaccid myelitis may also affect the nerves controlling the head and neck, causing facial weakness, drooping of the eyelids, and difficulty swallowing, speaking, or moving the eyes. A serious complication of AFM is respiratory failure if the breathing muscles become weakened.

Medical Author: John P. Cunha, DO, FACOEP
Medically Reviewed on 3/11/2019

Acute Flaccid Myelitis (AFM) Symptoms

Symptoms of AFM include sudden (acute) weakness in the arm(s) or leg(s), along with loss of muscle tone and decreased or absent reflexes. Some people with AFM report pain. In some cases, AFM can affect the nerves controlling the head and neck, causing facial weakness, drooping of the eyelids, and difficulty swallowing, speaking, or moving the eyes.

Acute Flaccid Myelitis (AFM) Causes

Many times symptoms of AFM develop after a viral infection, such as poliovirus, West Nile virus, and adenovirus. In some cases no clear possible cause is found. In addition, even when associated with a viral infection, it is not known how the infection triggers AFM, and it is not clear why some people develop AFM after an infection and others do not.

West Nile Virus Infection Causes, Symptoms, and Treatment Slideshow

West Nile Virus Infection Causes, Symptoms, and Treatment Slideshow

West Nile virus (WNV) is a flavivirus (virus transmitted by mosquitoes and ticks) and is commonly found in Africa, West Asia, the Middle East, and the Caribbean. The Culex pipiens mosquito is a known vector (an agent that transmits the infectious disease from one organism to another) for the West Nile flavivirus. It is closely related to the St. Louis encephalitis virus that is found in the United States. It can infect humans, birds, mosquitoes, horses, and some other mammals. West Nile virus infection is also sometimes referred to as West Nile fever (WNF) or West Nile encephalitis (WNE).

REFERENCE:

Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.

CONTINUE SCROLLING FOR RELATED SLIDESHOW