Table 7.

Diagnostic criteria of PANCS in adults and children

Adults
Histopathological patterns of vasculitis	Microscopic findings (brain biopsy)
Granulomatous	Vasculocentric mononuclear inflammation with multinucleated giant cells arranged in epithelioid granulomas with transmural destruction of the vessel wall. Leptomeningeal and intraparenchymal vessels may be involved
Lymphocytic	Perivascular lymphomonocyte infiltrate with involvement of the vessel wall. Rare and occasional plasma cells may be present
Necrotizing	Transparietal fibrinoid necrosis of vessels with associated inflammatory infiltrate
Children
Angiographically defined cPACNS	Findings and disease course
Non-progressive cPACNS	A devastating, monophasic inflammatory vessel disease of the CNS with stable MRI at 3 months
Progressive cPACNS	A chronic inflammatory disease defined by new segments of stenosis on angiography after 3 months of disease when untreated
Angiography-negative cPACNS (small-sized vessels)	n/a