Cerebral amyloid angiopathy presenting as a posterior leukoencephalopathy: a case report and review of the literature.

Cerebral amyloid angiopathy (CAA) is well known to present with lobar intracerebral hemorrhage, dementia or transient neurological events. White matter changes with CAA have only been recently described and can be seen with either sporadic or familial CAA. We present a 50-year-old man with rapidly progressive dementia in whom MRI brain showed symmetrical white matter changes in the parieto-occipital regions. Brain biopsy revealed changes of CAA along with features of Alzheimer's disease. Immunohistochemistry revealed amyloid beta protein. The subcortical lesions were thought to occur from hypoperfusion of the distal white matter. The role of amyloid in the pathogenesis of CAA and the mechanism of leukoencephalopathy are discussed.