Knowledge Shot: What is acute flaccid myelitis, the polio-like paralyzing disease

Acute flaccid myelitis—or AFM—is inflammation of the spinal cord that causes sudden muscle weakness. It’s a rare condition, fewer than one in a million people will get it a year, and it mainly affects children.

This disease has been in the news recently it looks like there are going to be more cases of AFM in 2018 than we saw last year.

This disease causes polio-like symptoms and while it can be caused by poliovirus, it can also be caused by environmental toxins, West Nile Virus, autoimmune diseases, and enteroviruses—especially enterovirus 68.

Unfortunately, the cause for many cases has not been determined. Let’s break down what happens.

The spinal cord, of course, is part of your nervous system and roughly speaking it allows for communication between your brain and all of the nerves that snake through the rest of your body.

When you step on a lego with your bare foot, your brain receives an inbound message about pain, and then sends an outbound message that tells your leg muscles to lift your foot, and your throat muscles to howl in pain.

Both the inbound and outbound messages are sent through the spinal cord. The cells that transmit these messages are called neurons, and they can be incredibly long—even up to a few feet long!

These neurons have different parts to them. They receive information through structures called dendrites, which then enter the cell body, which is like the cell’s headquarters.

The information might then move through a long fiber-like structure called the axon, and finally to the synaptic terminal— which passes the information to another neuron.

Now, if you take a cross-section of the spinal cord you’ll see that there’s white matter and gray matter. The gray matter contains the cell bodies of millions of neurons and the white matter is composed of millions of axons passing up and down.

In AFM, the gray matter gets damaged, and if the cell’s headquarters are damaged, the neuron won’t be able to pass messages back and forth anymore.

That’s why children with the disease get muscle weakness of their arms, legs, face, mouth, or eye muscles—or even total paralysis.

It all depends on which neurons are damaged. Usually, though, parents notice the loss of use of a child’s arm or leg.

Generally, the disease is diagnosed with an MRI that shows degradation of the gray matter. In some cases of AFM, children recover fully, and in other cases they have lasting effects.

Depending on the cause and severity there are some treatments like IVIG, steroids, and physical therapy that can help—so an early diagnosis is important.

While there is no vaccine for enterovirus 68, the CDC does recommend getting the poliovirus vaccine—which is part of the normal immunization schedule—and practicing good hygiene to prevent the spread of these viruses.

To find out more about the diseases of the nervous system, like poliomyelitis, check out our full selection of videos at Osmosis.org!