The role of small vessel disease in development of Alzheimer's disease

Classically Alzheimer's disease and vascular dementia have been considered as two different entities, with their own clinical criteria, but relatively recent epidemiological and clinicopathological studies suggest an overlap between them sharing not only most of the risk factors and some clinical aspects but also pathophysiological mechanisms. Cerebrovascular lesions, especially small vessel disease (lacunar infarcts, white matter hyperintensities and microbleeds), may magnify the effects of mild Alzheimer's disease pathology and promote the progression of cognitive decline and may also be a precursor of neuronal damage and dementia. "Vascular hypothesis" of Alzheimer's disease would open a window for new approaches and treatments.