ABSTRACT
Cerebrovascular disease is distinctly heterogeneous but may lead to vascular cognitive impairment or vascular dementia (VaD). Previous autopsy series of dementia cases have reported frequencies of VaD to vary widely (0.03-58 per cent) but use of current clinical diagnostic criteria suggests worldwide prevalence to be 10-15 per cent. Atherothromboembolism and intracranial small vessel disease are the main causes of brain infarction. Consistent with the subclassification of VaD lacunar infarcts or multiple microinfarcts in the basal ganglia, thalamus, brain stem and white matter are associated with more than 50 per cent of the cases. White matter changes including regions of incomplete infarction are usually widespread in VaD but their contribution to impairment is not explicit. Other pathologies including remote hippocampal injury, neocortical neuronal demise and Alzheimer type of lesions may modify the course of dementia. While most of VaD occurs sporadically, only a small proportion of cases bear apparent familial traits. CADASIL is likely the most common form of hereditary VaD, which arises from small vessel disease. Relative to other common dementias, the neuropathological substrates of VaD need unambiguous definition to impact on preventative and treatment strategies, and are critical for selective recruitment to clinical trials.
