Cerebral amyloid angiopathy and dementia

Cerebral amyloid angiopathy (CAA) is one of the most frequent causes of intracerebral hemorrhage (ICH). The deposition of beta amyloid leads to vascular fragility due to degeneration of vessel walls, formation of microaneurysms particularly in cortical blood vessels and fibrinoid vessel wall necrosis. The Congo red positive amyloid deposits are biochemically similar to the material comprising senile plaques in Alzheimer's disease. Recurrent or multiple simultaneous hemorrhages particularly in older patients should raise the suspicion of CAA. Gradient echo magnetic resonance imaging (MRI) is a sensitive, non-invasive technique for identifying even very small hemorrhages and superficial siderosis, which may cause transient symptoms in CAA. There is also a correlation between CAA, microbleeding and cognitive decline. Inflammatory variants of CAA must be suspected whenever patients present with progressive dementia, headache and multifocal symptoms in association with CAA findings in MRI. Histopathologically, a distinction is made between CAA-related inflammation (CAA-ri) with perivascular inflammatory infiltrates and amyloid beta-related angiitis (ABRA) with histological detection of transmural vasculitis. Inflammatory variants should be treated with corticosteroids and immunosuppressants.