Rapidly progressive dementia due to leukocytoclastic vasculitis of the central nervous system.

A 70-year-old male was admitted with a 2-week progressive course of severe cognitive impairment, scoring three on the Mini Mental State Examination. MRI of the brain showed confluent hyperintense areas in T2/FLAIR in the periventricular and subcortical white matter, extending to right parietal cortex and basal ganglia. Intra-arterial angiography was unremarkable. A targeted stereotactic brain biopsy disclosed a leukocytoclastic vasculitis. The patient improved on steroids. Leukocytoclastic vasculitis adds to the spectrum of histopathologic subtypes of primary angiitis of the central nervous system.