Primary angiitis of the central nervous system

**Definition:** In primary angiitis of the central nervous system, vasculitis is limited to the central nervous system. Primary angiitis of the central nervous system is a very rare disease, and its manifestation can be mimicked by many other diseases. Patients with primary angiitis commonly show headache, waxing and waning altered mental status, and transient ischemic attack-like events. Diagnosis is often based on angiography, although brain biopsy remains the only definitive diagnostic test.