Vascular cognitive impairment: epidemiology, subtypes, diagnosis and management.

Dementia occurs after stroke in 25% of patients but also can arise from covert cerebrovascular disease (CVD). 'Silent' lacunes occur in 25% of the elderly, often associated with focal or confluent hyperintensities on T2-weighted magnetic resonance imaging, which are detected in 95% of seniors. These covert infarcts predict future stroke and faster cognitive decline. Best practice guidelines advocate screening for cognitive impairment in all phases of overt stroke, when covert CVD is uncovered, when vascular risk factors are present and if patients present with cognitive complaints. Standardised testing is recommended, emphasising executive function and speed of processing. Cholinesterase inhibitors have cognitive enhancing effects in vascular dementia, but the major thrust is still aggressive management of vascular risk factors and healthy lifestyle choices. Given that mixed Alzheimer's dementia and CVD is likely the most common substrate for dementia and that they share common vascular risk factors, a major goal for vascular medicine is cerebrovascular protection, not just to prevent heart attack and stroke, but also to maintain brain health and delay dementia.