Primary CNS vasculitis: Pathophysiological diversity

Primary central nervous system vasculitis (PCNSV) is a rare vasculitis that affects the brain and occasionally the spinal cord of adults and children. Extensive progress has been achieved in the recognition of clinicopathological subsets that has translated into useful nosology reflective of the natural history and response to immunosuppressant treatment. Affected patients with small-artery vasculitis characterized by positive histology, negative cerebral angiography and prominent leptomeningeal enhancement on MRI after intravenous gadolinium administration have a milder disease course and more favorable outcome compared to those with large-artery PCNSV with multiple large-artery stenoses on cerebral angiography and extensive lesions on MRI. Subsets of patients presenting with rapidly progressive PCNSV, solitary tumor-like mass lesion and vascular amyloid deposits have the worst prognosis.