Diagnostic approach for children with suspected childhood primary angiitis of the central nervous system presenting with an encephalitis-type phenotype

cPACNS: childhood angiitis of the central nervous system; MRI: magnetic resonance imaging; CBC: complete blood count; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; BUN: blood urea nitrogen; CSF: cerebrospinal fluid.

* Patients with AP-cPACNS may have normal or somewhat nonspecific findings on brain MRI. Abnormal findings include T2 sequence hyperintensities and contrast enhancement. Refer to UpToDate topic for additional details.

¶ Blood cultures and antibody testing for bacterial, viral, and fungal causes varies by geography and potential exposure. Refer to UpToDate topics for additional details.

Δ Testing typically includes antineuronal antibodies. Additional rheumatologic and other autoimmune testing may be performed for patients with clinical features suggestive of a systemic inflammatory disease such as systemic lupus erythematosus or sarcoidosis. Testing may include antinuclear antibodies, antineutrophil cytoplasmic antibodies, extractable nuclear antigens, anti-double strand DNA (deoxyribonucleic acid), and quantitative immunoglobulin levels.

◊ CSF analysis is performed to evaluate for inflammatory, infectious, and neoplastic conditions (eg, multiple sclerosis, infectious meningitis, neurosarcoidosis, leptomeningeal malignancy). Testing typically includes cell count, protein, glucose, bacterial, viral, and fungal cultures, oligoclonal bands, lactate, and cytology. Refer to UpToDate topic for additional details.