Non-progressive large vessel CNS vasculitis (NP-cPACNS) also called Focal Cerebral Arteriopathy (FCA) is a subtype of childhood primary CNS vasculitis that affects medium-large blood vessels. This subtype often presents as acute ischemic stroke. It has a monophasic disease course.

The following is a list of clinical features, laboratory features, imaging features, and treatment methods associated with NP-cPACNS. This is intended for physicians. Parents and family members of suspected children may print the following and discuss with their physicians.

• NP-cPACNS children typically present with unilateral arterial ischemic stroke. Focal neurological deficits including hemiparesis, hemifacial weakness, hemisensory loss, fine motor deficits, and dysphagia often result. Severe headaches are common in this subtype of cPACNS.
• Diffuse neurological deficits, such as cognitive dysfunction and behaviour changes, are less common in this subtype.
• Seizures and constitutional symptoms (such as fever, fatigue, malaise, decreased energy, and weight loss) are less common in this subtype.

• Serum markers such as erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and immunoglobulin G (IgG) are frequently normal.
• von-Willebrand-factor antigen, a glycoprotein present in blood serum produced by endothelial cells, may be an additional marker of disease activity. von-Willebrand-factor antigen is commonly found to be elevated in NP-cPACNS children.
• CSF findings may also be normal except for possible increased CSF opening pressure and presence of Varizella Zoster Virus (VZV). CSF and serological exams for VZV and other viruses should be performed.

• Magnetic Resonance Imaging (MRI) is the preferred imaging modality of NP-cPACNS. Computed tomography (CT) is not sensitive enough to detect inflammatory lesions in cPACNS children; however, ischemic lesions may be detected. On MRI, unifocal lesions are associated with NP-cPACNS.
• Vascular imaging is crucial. Magnetic Resonance Angiography (MRA) cerebral vessel wall imaging with gadolinium enhancement should be considered. Evidence of wall thickening, edema and contrast wall enhancement can support active vessel wall inflammation. Conventional Angiography (CA) and/or MRA are required to detect arterial vessel abnormalities such as stenoses in children with suspected cPACNS. Children are likely to have evidence of proximal vessel stenosis involving the middle, anterior, or posterior cerebral arteries and distal internal carotid arteries on angiography.
• It is mandatory that children with NP-cPACNS have no new areas of inflammation in previously unaffected vessels on repeat imaging after three months of diagnosis. In case of progression of inflammation at three months, the diagnosis has to be revised to progressive cPACNS and the child should be treated accordingly.

• Many institutions have adopted the SickKids NP-cPACNS treatment protocol. Children with NP-cPACNS commonly receive three to seven days of IV methyl-prednisolone pulse followed by initiation of oral prednisone.
• The child will repeat vascular imaging at three months of prednisone therapy. If the result shows no new vascular territory involvement, the oral prednisone is tapered to zero over the next four weeks. If new vascular territory involvement is discovered, the child starts the progressive cPACNS treatment protocol.
• Anticoagulation with heparin is usually initiated at presentation, and is followed by antiplatelet therapy.
• The exact treatment protocol for children with non-progressive cPACNS is still being improved and constantly updated.