Cerebral amyloid angiopathy--an underdiagnosed entity in younger adults with lobar intracerebral hemorrhage?

Cerebral amyloid angiopathy (CAA) is a progressive microvascular amyloidosis affecting the small- and medium-sized arterioles and the capillaries of brain parenchyma and leptomeninges, and is recognized as a cause of lobar intracerebral hemorrhage (ICH). We report two patients who experienced recurrent ICH due to CAA at an age of 37 (A) and 42 (B) years, respectively. The classic and modified Boston criteria for the diagnosis of CAA include an age limit of 55 years if no biopsy or postmortem examination is performed; CAA is typically not considered in the differential diagnosis of lobar ICH in younger patients. We assume that sporadic CAA is an underdiagnosed entity in younger adults with lobar ICH.