Acute flaccid myelitis (AFM) is an unusual neurological condition that affects the spinal cord, which causes muscular weakness.
AFM is a rare condition. Similar to polio, which affects the nerves in the spinal cord. This condition tends to occur in children. This condition can cause weakness in the arm or leg and other symptoms unexpectedly.
Acute Flaccid Myelitis affects the nerve, causing weakness of the muscles, the face, the neck, the body, and the difficulty of speech. This of course can be fatal to the growth of children who experience AFM.
According to the Center for Disease Control and Prevention (CDC), more than 90% of cases occur in children.
Researchers and scientists have not yet understood everything about this condition, but organizations like the CDC are researching it and trying to get more information.
AFM affects the central nervous system (CNS). The most affected part is the spinal cord area called gray matter.
Although AFM has some similarities with polio, since 2014, all the tests for polio on people with AFM are negative.
Acute Flaccid Myelitis Symptoms that need to be aware of
The disease is commonly caused by various viruses such as adenoviruses, polioviruses, other enteroviruses, and West Nile viruses. Every parent should be wary of the following AFM symptoms, contact your doctor immediately when these things happen to your child:
- Sudden weakness in the arms and legs, along with loss of muscle tone
- Neck, back, and leg pain
- Drooping eyelids and difficulty moving the eyes
- Droop on the face.
- Difficulty swallowing or speaking
- Talk is unclear
- Difficulty breathing.
People may also experience numbness and tingling and find that they are unable to urinate. However, these symptoms are less common.
In very severe cases, AFM can cause breath failure and sudden changes in temperature and blood pressure.
Causes of AFM
The US has been free polio since 1979. AFM cases in the US since 2014 are similar to polio but not for polio virus. The cause must have only been found in some recent cases with the detection of Coxsackievirus A16, Enterovirus (EV)-A71, or EV-D68 in the cerebro-spinal fluid (CSF).
These three viruses are the same type of enterovirus as polio virus. Enterovirus is a virus that usually enters through the intestinal tract.
Doctors have suspected that many recent AFM patients, in which spinal fluid does not identify viruses that cause AFM, may be caused by EV-D68. It is based on indirect evidence.
According to the CDC, the AFM case spike in 2014 is linked to the national respiratory outbreak of EV-D68. It is unknown why only a handful of those who have respiratory diseases continue to develop the AFM. Researchers hypothesize that genetic factors as well as unusual immune responses may be responsible.
Recent AFM cases usually occur in cycle patterns in late summer and early autumn, and are “skipped” a year, with more cases reported at 2014, 2016 and 2018 compared to 2015 and 2017.
Differential diagnosis of AFM
Due to the symptoms of AFM similar to some other viral infections and neurodegenerative disorders, it is important to distinguish them from the following disorders at the time of diagnosis:
- Guillain-Barre syndrome (GBS)
- Transverse Myelitis
- Acute Encephalomyelitis disseminated (ADEM)
- Infarction of spinal cord
- Early “spinal shock”.
Unlike the GBS, where the symptoms presented are usually symmetrical (e.g. Paralysis affecting both upper limbs), the AFM signs are usually dispersed and asymmetrical. MRI scans, as well as additional tests as shown, must be carried out to present a precise diagnosis.
Examples of laboratory test recommendations for patients with suspected AFM:
- Test the cerebrospinal fluid (CSF),
- Nerve conduction velocity (NCV,
- Electromyography (EMG) to test the muscle response to stimulation of nerve cells,
- Respiratory Panels (PCR)
- Enterovirus PCR
- West Nile IgG and IgM Virus in serum
- EBV Antibodies
- Lyme serology (if any).
Thank you very much for reading Acute Flaccid Myelitis: Symptoms, Causes, and Diagnosis, hopefully useful.