Abstract
A 59-year-old man with progressive cognitive decline and mood disturbances was admitted to the hospital. Brain magnetic resonance imaging revealed marked white matter hyperintensity (WMH) and widespread lobar cerebral microbleeds. Because he had untreated hypertension, we started antihypertensive treatment and found a significantly improved cognitive function and WMH regression. We diagnosed him with cerebral amyloid angiopathy (CAA) based on the modified Boston Criteria with the rare apolipoprotein E (ApoE) ε2/ε4 genotype. The mechanism underlying reversible leukoencephalopathy in CAA may be related to the loss of autoregulation of brain circulation: cerebrovascular amyloid β deposits damaged the blood-brain barrier of the capillaries, which led to vasogenic edema induced by blood pressure surges.