Acute Flaccid Myelitis?

Acute Flaccid Myelitis?

Multiple news media outlets have been reporting new cases of acute flaccid myelitis, a rare polio-like disorder primarily affecting children.  This rare disease has been on the rise, according to the Centers for Disease Control (CDC), since 2014.  The CDC has reported a total of 362 cases between August 2016 – August 2018.  However, the Minnesota Department of Health announced that 6 cases have recently been classified and reported in its state.  All 6 cases were in children under 10 years of age.  In previous years, Minnesota typically saw 1 patient or less with acute flaccid myelitis.  The highest acuity year was 2014, when 3 patients were diagnosed with the disease.

In many cases the cause acute flaccid myelitis is not able to be determined, but enteroviruses are believed to be a major cause.  The increase in cases in 2014 were associated with a national outbreak of enterovirus D68, however, a direct causal link was never proven. It is widely accepted that acute flaccid myelitis occurs as a consequence of a viral infection, but it is hypothesized that unrecognized genetic and environmental factors may also determine which individuals contract the disease.

Despite the increasing incidence, the CDC estimates that only about 1 in 1,000,000 individuals contract acute flaccid myelitis each year.  Symptoms primarily involve the central nervous system and often begin with rapid onset of muscle weakness in the extremities. Patients may also experience neck stiffness, difficulty speaking, and drooping of the eyelids. The most severe complication is respiratory failure associated with weakness of the respiratory muscles. Patients do not typically report numbness or tingling, which may help differentiate this from other nervous system processes.

The only treatment is supportive care, including mechanical ventilation as indicated for the most severe cases.  Patients may require aggressive physical and occupational therapy.  There is no set or specific timeline for recovery.  Due to the rarity of the disease and unclear cause, the prognosis is variable.  As the cause is believed to be viral, the best preventative measures include hand-washing and avoiding sick contacts.

Read more about acute flaccid myelitis:

Current Diagnosis & Treatment: Pediatrics, 24e: Chapter 40: Infections: Viral & Rickettsial 

Current Medical Diagnosis & Treatment 2019: Chapter 32: Viral & Rickettsial Infections 

Centers for Disease Control (CDC) 

Minnesota Department of Health