Acute Flaccid Myelitis: Etiologic Challenges, Diagnostic and Management Considerations

Purpose of review Acute flaccid myelitis is a polio-like illness defined by the acute onset of flaccid paralysis in the setting spinal MRI demonstrating a longitudinal lesion in the gray matter of the cord. This paper aims to review the current state of knowledge and key clinical points for the diagnosis and management of acute flaccid myelitis. Recent findings There were clusters of AFM noted in California and Colorado in 2014, with additional cases across the USA that year, and another spike in cases in 2016. Patients have been managed with classic treatments for transverse myelitis, but in general without benefit, although some colleagues have noted anecdotal improvement in individual patients. Our current practice at the Children's Hospital of Philadelphia is to initiate therapy with intravenous immunoglobulin (IVIG) upon recognition of acute flaccid myelitis in hopes of boosting humoral immunity, and to provide an emphasis on rehabilitation services, including physical and occupational therapy. There is some data that suggests a connection to the virus enterovirus D68 (EV D68), but there has been no definitive link. Publications regarding longer-term outcomes in these patients are early in development and, thus far, only provide data for 6 to 12 months from onset. Summary AFM is a serious illness with long-term consequences, and we have much to learn. Key areas in need of further investigation involve etiology, host susceptibilities, treatment options, and long-term outcome. Individual clinicians can assist in these efforts by the prompt reporting of cases of AFM to the US Centers for Disease Control and Prevention.