Proposed Diagnostic Criteria
Taking into account the previously outlined elements of clinical history (H), examination (E), neuroimaging (NI), and CSF analysis (CSF), we propose the following diagnostic criteria for AFM.
These consensus diagnostic criteria are designed to be applied in the acute phase of the illness to classify the level of certainty of a diagnosis of AFM and to help distinguish AFM from other causes of acute flaccid paralysis.
Our consensus criteria classify AFM cases using typical features, but as a clinician, you may encounter patients with atypical features. They are not meant to replace reasoned clinical judgment on a case to case basis.
Additionally, the diagnostic criteria outlined here are also not intended to replace epidemiologic case definitions for acute flaccid paralysis or AFM that public health organizations (such as the World Health Organization or US Centers for Disease Control and Prevention) use for surveillance purposes.
a. Subjective (H1) or objective (E1) weakness must be present in any of: limb(s), neck, or cranial nerves.
b. Prodromal illness may include respiratory, gastrointestinal, or other symptoms of viral illness.
c. Normal or increased reflexes may be found in other limbs.
d. If MRI obtained very early (within hours of neurological onset) appears normal, repeat MRI after clinical evolution may show diagnostic findings. MRI obtained at late stages (≥4 weeks) may be normal.
e. CSF may be normal at very early (hours) or late (≥4 weeks) stages of AFM.
f. At present, there are a lack of data describing the frequency of these features in patients with AFM