Cyclophosphamide treatment of primary angiitis of the central nervous system in children: report of 2 cases.

Primary angiitis of the central nervous system (PACNS) is a rare, idiopathic vasculitis diagnosed most frequently in adults. We describe 2 children presenting with hemiplegia from PACNS treated with cyclophosphamide. Diagnosis in one child was based on abnormal angiography. Oral, but not intravenous (IV), cyclophosphamide was effective in preventing progressive weakness. The second child had unremarkable angiography, but brain biopsy revealed vasculitis; IV cyclophosphamide prevented further weakness. Both cases highlight the importance of early diagnosis and treatment.