Vascular dementia: a pragmatic review

Over the past 100 years, our understanding of dementia has undergone considerable change. For much of that time, ‘senility’ was seen as an almost inevitable concomitant of ageing, and was usually attributed to atherosclerosis. In the postwar period, a concept of multi-infarct dementia emerged (Hachinski 1974), but at the same time Alzheimer’s disease came to be seen not as a rare early-onset disorder, but as the cause of most cases of dementia. Indeed, the concept of dementia itself was built around the impairments seen in Alzheimer’s disease, notably the impairment of memory. With greater understanding of dementia, particularly its pathological basis, it came to be realised that many different kinds of pathology can produce a dementia syndrome, and that multiple types of pathology are the rule rather than the exception. This article reviews our current under standing of how cerebrovascular disease contributes to cognitive impairment. Our aim is to help those involved in the assessment and management of people with cognitive impairments to understand the strengths and limitations of our current concepts, and to inform diagnosis and management. We try to tease apart the strands of clinical, imaging and pathological evidence about vascular dementia/vascular cognitive impairment in order to achieve improved clarity about the nature of the disease. We try to reach pragmatic conclusions, rather than provide a comprehensive account of a complex area of research.