For the diagnosis pediatric CIS, all of the following is required:
− A monofocal or polyfocal, clinical CNS event with presumed inflammatory demyelinating cause.
− Absence of a prior clinical history of CNS demyelinating disease (e.g. absence of past optic neuritis (ON), transverse myelitis (TM) and hemispheric or brain-stem related syndromes).
− No encephalopathy (i.e. no alteration in consciousness or behavior) that cannot be explained by fever.
− The diagnosis of MS based on baseline MRI features (as recently defined) are not met.
For pediatric ADEM, all of the following is required:
− A first polyfocal, clinical CNS event with presumed inflammatory demyelinating cause.
− Encephalopathy that cannot be explained by fever.
− No new clinical and MRI findings emerge 3 months or more after the onset.
− Brain MRI is abnormal during the acute (three-month) phase.
− Typically on a brain MRI:
• diffuse, poorly demarcated, large (> 1–2 cm) lesions involving predominantly cerebral white matter;
• deep grey matter lesions (e.g. thalamus or basal ganglia) may be present;
• T1-hypointense lesions in the white matter are rare.
For pediatric NMO, all of the following are required
− Optic neuritis.
− Acute myelitis.
− At least two of three supportive criteria:
* contiguous spinal cord MRI lesion extending over three vertebral segments;
* brain MRI not meeting diagnostic criteria for MS;
* aquaporin IgG seropositive status.
For pediatric MS, one of the following is required
− ≥ 2 non-encephalopathic, clinical CNS events with presumed inflammatory cause, separated
− by > 30 days and involving more than one CNS area.
− One non-encephalopathic episode typical of MS which is associated with MRI findings consistent with 2010 Revised McDonald criteria for dissemination in space (DIS) and in which a follow-up MRI shows at least one new enhancing or non-enhancing lesion consistent with dissemination in time (DIT) MS criteria.
− One ADEM attack followed by a non-encephalopathic clinical event, three or more months after symptom onset, that is associated with new MRI lesions that fulfill 2010 Revised McDonald DIS criteria.
− A first, single, acute event (e.g. a CIS) that does not meet ADEM criteria and whose MRI findings are consistent with the 2010 revised McDonald Criteria for DIS and DIT (applied only to children ≥12 years old).