Advances in Vascular Cognitive Impairment 2006

Abstract

Vascular cognitive impairment is common and represents a spectrum of cognitive dysfunction associated with stroke and cardiovascular risk factors which may be slight, moderate or severe.1 Recently and as a major advance, the National Institute of Neurological Disorders and Stroke—Canadian Stroke Network Vascular Cognitive Impairment Harmonization Standards Working Group published clinical and research standards for the description and study of vascular cognitive impairment.2 In this update we report advances in vascular cognitive impairment in the following areas: clinical trials and treatment, new risk factors, white matter disease, and genetics. Cardiovascular risk factors such as blood pressure elevation and hyperglycemia are prime targets for clinical trial study because they are believed to cause negative effects on brain structure and cognitive function and may even influence risk of Alzheimer disease (AD).3 Results of recently published observational epidemiological studies have fueled controversy in relation to the role of blood pressure on cognition because some studies such as the Honolulu Asia Aging Study4 and Cache County Study5 suggest that antihypertensive therapy may reduce risk of dementia and cognitive decline or reduce incidence of AD, respectively, whereas the Religious Orders Study6 did not find an association between blood pressure and risk of AD or cognitive decline. Meta-analysis of patients with cardiovascular and/or cerebrovascular disease who received blood pressure-lowering treatment show a trend toward prevention of dementia and/or cognitive decline;7 however, a systematic analysis of 3 studies comprising 12 091 patients with hypertension who were treated with either medication or lifestyle strategies for at least 6 months show no evidence that blood pressure-lowering prevents dementia or cognitive impairment.8 Lack of definitive results in some of these trials may be explained by insufficient power to detect treatment effects, measurement error in cognitive end points, variation in treatment effects between …