Angiography-negative childhood primary angiitis of the central nervous system diagnosed by open brain biopsy: a case report.

Childhood primary angiitis of the central nervous system (PACNS) is rare and has been poorly defined, which makes it difficult to diagnose and treat. Herein, we report a case of childhood PACNS that was diagnosed by open brain biopsy. Clinical symptoms and radiologic findings improved after combination treatment with steroid and cyclophosphamide. In this case, a 16-year-old, previously healthy, adolescent male complained of headache, seizure, and right-side weakness with hypoesthesia. Brain magnetic resonance imaging (MRI) showed multifocal, high-signal intensity lesions on T2-weighted scans with patch contrast enhancement. The clinical symptoms improved after intravenous steroid pulse therapy (methylprednisolone, 1,000 mg/day for 3 consecutive days) and subsequent oral steroid maintenance. However, follow-up brain MRI showed aggravation of the previous lesions. Open brain biopsy of the left parietal lobe showed infiltration of lymphoplasma cells to the vessel walls with parenchymal necrosis, consistent with PACNS. The patient received four monthly intravenous cyclophosphamide (1,000 mg/dose at each cycle) treatments along with oral steroid maintenance. After treatment, he was symptom-free, and follow-up MRI revealed marked lesion improvements. This case suggests the important role of brain biopsy and aggressive immunosuppressive treatment in diagnosis and management of childhood PACNS.