Navigating Through the Recent Diagnostic Criteria for MOGAD

International criteria for the diagnosis of myelin oligodendrocyte glycoprotein–associated disease (MOGAD) were published in The Lancet Neurology ® on January 24, 2023.1 The criteria recommend that patients with a clinical event typically associated with MOG antibody (Ab) (optic neuritis, myelitis, acute disseminated encephalomyelitis, cerebral monofocal or polyfocal deficits, brainstem or cerebellar deficits, cortical encephalitis often with seizures) and clear positive serum MOG-Ab results can be diagnosed with MOGAD. A clear positive test is defined as MOG-Ab measured by fixed cell-based assay (CBA) with a titer ≥1:100 or live CBA with a standardized method (that is a clear positive according to the individual assay cutoffs). Patients with low positive serum MOG-Ab titers can be diagnosed with MOGAD if they possess at least 1 supporting clinical or MRI feature. In cases of optic neuritis and myelitis, the supporting features include bilateral simultaneous optic neuritis, longitudinally extensive spinal cord, or optic nerve involvement or a conus lesion. Supporting features can also be applied to patients with positive MOG-Ab results without reported titers and patients with negative serum but positive CSF MOG-Ab. These diagnostic criteria require the exclusion of alternative diagnoses, including multiple sclerosis (MS).