Welcome to the Rare Classroom, a new series from Patient Worthy. Rare Classroom is designed for the curious reader who wants to get informed on some of the rarest, most mysterious diseases and conditions. There are thousands of rare diseases out there, but only a very small number of them have viable treatments and regularly make the news. This series is an opportunity to learn the basics about some of the diseases that almost no one hears much about or that we otherwise haven’t been able to report on very often.

Eyes front and ears open. Class is now in session.

The disease that we will be learning about today is:

Acute Flaccid Myelitis

What is Acute Flaccid Myelitis?

• Acute flaccid myelitis is a rare condition that affects the spinal cord.
• In the past, polio could cause the disease, but as of 2014 no cases in the US have been linked to polio
• It can trigger a rapid onset of serious symptoms, such as breathing problems, weakness, and decreased reflexes
• The majority of cases take place in children
• Cases have increased in recent years, but acute flaccid myelitis remains incredibly rare, affecting about 1 in 500,000 children annually in the US
• Diagnosis involved evaluation of the nervous system and spinal cord imaging
• For reasons that are unclear, cases tend to occur in late summer and early fall

How Do You Get It?

• The cause of acute flaccid myelitis is not well understood and has been attributed to a variety of factors.
• The condition often takes place soon after recovery from a mild viral infection, or at least symptoms that resemble one
• The CDC lists a number of potential factors, such as:
  • Viruses, such as polio, enteroviruses, adenoviruses, and West Nile Virus
  • Genetic disorders
  • Environmental pollutants
• Overall, the cause remains unclear, but viral activity is likely to play a role

What Are The Symptoms?

• Acute flaccid myelitis can inflict a number of serious signs and symptoms.
• A diagnosis requires at least one gray matter lesion on the spinal cord and acute onset limb paralysis.
• A full list of symptoms include:
  • Sudden weakness affecting the arms and/or legs
  • Difficulty speaking and swallowing
  • Decreased reflexes
  • Facial droop and weakness
  • Trouble moving the eyes and eyelids
  • Urinary retention
  • Trouble breathing
  • Grey matter lesions on the spinal cord
  • Dysfunction of the cranial nerve

How Is It Treated?

• Outcomes can vary greatly for acute flaccid myelitis, but in many instances, outcomes are poor
• This is partially a result of the treatments options for the disease, which are limited in effectiveness
  • Treatment is generally supportive and symptomatic
  • Some patients will require physical therapy or occupational therapy
  • In severe cases, mechanical ventilation may be needed
• Many survivors are left with permanent weakness
• The effect of treatments such as immunoglobulin, antiviral therapy, corticosteroids, and plasma exchange is unclear

Where Can I Learn More???

• Check out our cornerstone on this disease here.
• Learn more about this condition from the Centers for Disease Control and Prevention (CDC).