Cerebrovascular disease, vascular cognitive impairment and dementia

Vascular cognitive impairment (VCI) is the latest modification of nosological terminology that aims to encompass all the effects of vascular disease or lesions on cognition. It incorporates the complex interactions between vascular aetiologies, risk factors and cellular changes within the brain and cognition. VCI refers to all aetiologies of cerebrovascular disease (CVD), including vascular risks that can result in brain damage, leading to cognitive impairment, from the earliest deficits to a severe and broad dementia-like syndrome. VCI may include cases with vascular risk factors, stroke, infarcts and white-matter lesions, and also Alzheimer’s disease (AD) with co-existing CVD. Vascular dementia (VaD), a subset of VCI patients who fulfil dementia criteria, is considered the second most common cause of dementia. The main subtypes of vascular dementia include large-vessel cortical multi-infact dementia and small-vessel subcortical ischaemic vascular disease and dementia. Current criteria emphasize the stroke and infarct concept, they show good specificity but low sensitivity, and focus on the pure end of the VaD–AD spectrum. Clinical differentiation between VaD and AD with CVD remains a challenge. Findings that potentially identify AD with CVD include early prominent episodic memory impairment, early and significant medial temporal lobe atrophy on magnetic resonance imaging and low concentrations of cerebrospinal fluid amyloid peptides with high tau protein concentrations.