Prevention of Vascular Cognitive Impairment

Abstract

Dementia has become a pressing health issue, with numbers steadily increasing. Vascular injury is the second most common cause of dementia after Alzheimer disease (AD) and a defining feature of vascular cognitive impairment (VCI), which encompasses the full range from vascular dementia (VaD) to mild cognitive impairment of vascular origin.1,2 There are various manifestations of vascular brain injury, including silent or covert brain infarcts, white matter lesions, and clinically overt strokes, all of which may contribute to cognitive decline. Cerebral small vessel disease has been recognized as the most common etiology of VCI, but there are multiple vascular causes and mechanisms that share major risk factors and may run in parallel. Adding to this complexity, vascular pathology frequently coincides with neurodegenerative pathology and disentangling the contribution of individual pathologies to cognitive decline is notoriously difficult even with advanced diagnostic tools. This is reflected by current classification schemes, which distinguish between probable and possible VaD and probable and possible vascular mild cognitive impairment.2 However, there have been various sets of diagnostic criteria in the past, which must be kept in mind when interpreting the results from epidemiological studies and randomized controlled trials (RCT). Regardless of these methodological challenges, vascular brain injury represents an increasingly recognized target for prevention of cognitive decline and dementia. There are various modifiable factors that have been associated with VCI or VaD in clinical and epidemiological studies (Figure 1), although in many cases the causal relationships are not fully established and evidence for a preventive effect of strategies to control these factors is mostly weak. Figure 1. Risk factors for vascular dementia (VaD), Alzheimer disease (AD), unspecified dementia, and cognitive impairment. Findings are derived from epidemiological studies. Relevant references are detailed in Supplementary Table I. VaD and AD share many risk factors, although the level …