Childhood central nervous system vasculitis.

Childhood CNS vasculitis is a newly recognized disease entity, which can occur in isolation as a primary disorder - childhood primary angiitis of the CNS (cPACNS)-or secondary to systemic diseases. Since early initiation of treatment is associated with improved disease outcome, rapid evaluation and timely diagnosis are essential. The clinical presentation can be highly variable. Children present with newly acquired focal and/or diffuse neurological deficits and/or psychiatric symptoms. Inflammatory markers and CSF analysis are essential, but show limited sensitivity and specificity. MRI studies are highly sensitive for areas of focal inflammation, however lack specificity. Negative MRI studies do not exclude inflammatory brain disease. Angiography is the key diagnostic modality for large to medium vessel cPACNS. Characteristic angiographic findings include segmental cerebral vessel stenoses and corresponding contrast enhancement in the vessel wall. In children with normal angiography, confirmation of small vessel cPACNS requires brain biopsy. A thorough diagnostic evaluation for cPACNS should include a workup for causes of secondary CNS vasculitis, evaluation for CNS vasculitis mimics, and analysis of markers of nonvasculitic inflammatory brain diseases when appropriate. Early recognition with timely treatment of childhood CNS vasculitis can significantly alter the course of this potentially devastating disease.