Primary angiitis of the CNS.

Meaningful progress in our understanding and clinical approach to primary angiitis of the CNS (PACNS) has been made in the past three decades. Increased recognition of PACNS and general advances in diagnosis of neurological disorders have led to an aggressive diagnostic approach and a proliferation of case reports providing enriched clinical and pathological descriptions. We have witnessed major advances not only in the diagnosis of PACNS but in the recognition of its mimics. Epidemiological, clinical, neuroradiagnostic, and laboratory findings have enhanced our diagnostic accuracy and recognition of PACNS mimics, however, many challenges to our understanding and management of the disease in children and adults remain.