Acute Flaccid Myelitis

Key Points Acute flaccid myelitis (AFM) presents with acute onset of weakness and paralysis due to damage to the anterior horn cells of the spinal cord with median age at onset of 4 to 6 years.Incidence of AFM has fluctuated with biennial spikes occurring in the late summer and early fall.AFM has been associated with several viral infections including non-polio enteroviruses D68 (EV-D68) and A71 (EV-A71). The overwhelming majority of children who contract these viruses will not develop AFM.AFM is rare; however, it is important to maintain a high index of suspicion, as it is often initially underdiagnosed, leading to delayed escalation of care and substantial morbidity.Patients with symptoms that are concerning for AFM should be closely monitored for vital sign instability and respiratory decompensation.The Centers for Disease Control and Prevention (CDC) has maintained surveillance for AFM. Reporting patients under investigation is key, and the CDC website provides many helpful resources about AFM for clinicians.Management is largely supportive without a currently established evidence-based primary treatment. Ancillary therapies and a multidisciplinary approach to rehabilitation are essential.