CIS | A first monofocal or multifocal CNS demyelinating event; encephalopathy is absent, unless due to fever |
Monophasic ADEM | • A first polyfocal clinical CNS event with presumed inflammatory cause • Encephalopathy that cannot be explained by fever is present • MRI typically shows diffuse, poorly demarcated, large, >1-2 cm lesions involving predominantly the cerebral white matter; TI hypointense white matter lesions are rare; Deep grey matter lesions (e.g. thalamus or basal ganglia) can be present • No new symptoms, signs or MRI findings after 3 months of the incident ADEM |
Multiphasic ADEM | • New event of ADEM 3 months or more after the initial event that can be associated with new or re-emergence of prior clinical and MRI findings. Timing in relation to steriods is no longer pertinent. |
MS | Any of the following: • Two or more nonencephalopathic CNS clinical events separated by more than 30 days, involving more than one area of the CNS • Single clinical event and MRI features rely on 2010 Revised McDonald criteriab for DIS and DIT [4] (but criteria relative for DIT for a single attack and single MRI only apply to children ≥12 years and only apply to cases without an ADEM onset) • ADEM followed 3 months later by a nonencephalopathic clinical event with new lesions on brain MRI consistent with MS |
NMO | All are required: • Optic neuritis • Acute myelitis • At least two of three supportive criteria:  • Contiguous spinal cord MRI lesion ≥3 vertebral segments  • Brain MRI not meeting diagnostic criteria for MS  • Anti-aquaporin-4 lgG seropositive status |