How can cerebral infarcts and hemorrhages lead to dementia?

The incidence of new onset dementias is increased after stroke. The objecti ve of this review is to investigate how cerebral infarcts and hemorrhages c an lead to dementia. Stroke subtypes, total volume of cerebral lesion and f unctional tissue loss, and location of the lesions are the major determinan t of dementia in stroke patients. The causal relationship between stroke an d dementia is clear: (1) in young patients who are unlikely to have associa ted Alzheimer pathology; (2) when the cognitive functioning was normal befo re stroke, impaired immediately after, and does not worsen over time, (3) w hen the lesions are located in strategic areas; and (3) when a well-defined vasculopathy known to be associated with dementia is proven. However, whit e matter changes and associated Alzheimer pathology may also contribute to the dementia syndrome in stroke patients.