Article Text

Download PDFPDF
Update on acute flaccid myelitis: recognition, reporting, aetiology and outcomes
  1. Duriel Hardy,
  2. Sarah Hopkins
  1. Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
  1. Correspondence to Dr Sarah Hopkins, Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; hopkinss1{at}


Acute flaccid myelitis, defined by acute flaccid limb weakness in the setting of grey matter lesions of the spinal cord, became increasingly recognised in 2014 following outbreaks in Colorado and California, temporally associated with an outbreak of enterovirus D68 respiratory disease. Since then, there have been biennial increases in late summer/early fall. A viral infectious aetiology, most likely enteroviral, is strongly suspected, but a definitive connection has yet to be established. Patients typically present with asymmetric weakness, maximal proximally, in the setting of a febrile illness. MRI demonstrates T2/FLAIR abnormalities in the central grey matter of the spinal cord, and cerebrospinal fluid typically shows a lymphocytic pleocytosis with variable elevation in protein. The weakness may be progressive over several days and involve respiratory muscles, making early recognition and close monitoring essential. Other complications in the acute period may include autonomic instability and bowel/bladder involvement. There is no clear recommended treatment at this time, although intravenous immunoglobulin, steroids and plasma exchange have been used. Intensive therapies and rehab services have shown benefit in maximising function, and surgical interventions may be considered in cases without optimal response to therapies. Close attention should also be paid to psychosocial factors. Prognosis is generally guarded, and additional factors that predict final outcome, including host factors and treatment effects, have yet to be elucidated. Multicentre collaborative efforts will be required to provide answers about this rare but serious disorder.

  • weakness
  • pediatric
  • enterovirus
  • acute flaccid myelitis
  • myelitis

Statistics from


  • Contributors DH and SH both contributed to conceptualisation. DH drafted the initial paper, with significant edits and additional sections drafted by SH.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Disclaimer SH receives support from the Centers for Disease Control and Prevention for activities related to acute flaccid myelitis surveillance.

  • Competing interests None declared.

  • Patient consent for publication Not required.

  • Provenance and peer review Commissioned; externally peer reviewed.

  • Data availability statement There are no data in this work. N/A.

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.