Diagnostic Studies for AFM

Initial Neurodiagnostic Studies

Laboratory Tests

Cerebrospinal fluid (CSF)

Cell count with differential, protein and glucose; oligoclonal bands; meningitis/encephalitis PCR panel


Enterovirus (EV) PCR, anti-MOG (myelin oligodendrocyte glycoprotein) and anti-aquaporin antibodies, herpes simplex virus (HSV), Epstein-Barr virus (EBV), West Nile virus (WNV)


Enterovirus (EV) PCR

Nasopharyngeal (NP) and/or oropharyngeal (OP) swabs

Respiratory multiplex testing and enterovirus (EV) PCR


MRI of the spine and brain

Consider additional pathogen-specific testing (e.g., Lyme) based on seasonality, exposures, and geography.

Note: Some of these studies may require sedation, depending on child’s age

  • Coordinate the procedures to avoid repetitive sedation if possible
  • Monitor respiratory status continuously

Reference: Hardy D, Hopkins SE. Update on AFM: Recognition, reporting, aetiology, and outcomes. Arch Dis Child 2020. DOI: 10.1136/archdischild-2019-316817. Online ahead of print.

Laboratory Specimen Collection

Rapid specimen collection increases the chance of pathogen detection. Specific testing for AFM should be done in consultation with a neurologist and infectious disease specialists. Consider additional pathogen-specific testing based on seasonality, exposures, and geography and clinical presentation.

CSF, respiratory (NP/OP), serum, and stool specimens should be also sent to CDC for surveillance testing. Contact your health department to coordinate sending of specimens to CDC for testing.

MRI Imaging

Order MRI of the spine and brain with and without contrast.

  • Use the highest tesla scanner available (ideally 3T).

Imaging within the first 72 hours of limb weakness may be normal and should be repeated if clinically indicated. MRI imaging considerations:

  • Axial and sagittal images are most helpful in identifying lesions.
  • Multiple levels of the spinal cord are often involved, consider imaging entire spinal cord.
  • In patients with cranial nerve deficits, high cuts of brainstem or total brain MRI should be considered.
  • Although lesions are predominantly gray matter, some patients with AFM may also have some white matter involvement.

Reference: Maloney JA et al. MRI Findings in Children With Acute Flaccid Paralysis and Cranial Nerve Dysfunction Occurring During the 2014 Enterovirus D68 Outbreak. Am J Neuroradiol 2015;36(2):245-50.