Clinical Testing and Diagnosis for Acute Flaccid Myelitis

Recommended tests

Cerebrospinal fluid (CSF)

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

Serum

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

Stool

Enterovirus (EV) PCR

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

Respiratory multiplex testing and enterovirus (EV) PCR

Neuroimaging

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.

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

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.

What to do next

1. Identify PUI for AFM

PUI is a patient with onset of acute flaccid limb weakness (clinical criterion) AND an MRI with at least some gray matter lesions in the spinal cord (laboratory/imaging criterion). Please send information about this patient to the health department regardless of any laboratory results.

2. Collect specimens

• Collect specimens as close to onset of limb weakness as possible and handle and store as directed.

3. Contact health department

• Contact your state or local health department when you identify a PUI for AFM. See State and Local AFM Contacts for Clinicians for a complete list of health department contact information. If your health department's information is not on the list, call the CDC Emergency Operations Center at 770-488-7100.
• Work with your health department to coordinate submission of specimens for testing at CDC.

4. Compile clinical information

The health department will request additional information contained in medical records. Send copies of the following to your health department for sharing with CDC in order to assist with case classification:

• MRI report
• MRI images
• Neurology consult note (if available)

Coordinate with your health department to send information about PUIs and ship specimens to CDC.

Reporting cases

Health departments will coordinate sending specimens and clinical information to CDC.