Stroke-related dementia.

Three months after a stroke, one quarter to one third of patients meet operationalized criteria for dementia, and an even greater proportion have cognitive impairment short of dementia. A significant number of these patients had mental deterioration before the stroke, implying an underlying neurodegenerative process. Current diagnostic criteria do not reflect these facts, and in addition to artificially using cerebrovascular disease to differentiate Alzheimer's disease and vascular dementia, they do not allow researchers and clinicians to identify subjects at risk in the early stages of cognitive decline. To be clinically useful, a broader concept of cognitive impairment in the setting of vascular disease needs to be developed based on data collected prospectively using cohorts of stroke patients.