Plasma Homocysteine Levels, Cerebrovascular Risk Factors, and Cerebral White Matter Changes (Leukoaraiosis) in Patients With Alzheimer Disease

Abstract
LEUKOARAIOSIS,1 or white matter low attenuation, on computed tomographic (CT) scanning is frequently found in patients with cerebrovascular disease2 but has also been associated with dementia severity in Alzheimer disease (AD).3-6 The pathogenesis of leukoaraiosis is probably multifactorial and, at present, is poorly understood. Cerebrovascular risk factors associated with leukoaraiosis, such as increased blood pressure (BP), diabetes mellitus, the presence of the apolipoprotein E (APOE) ϵ4 genotype, and smoking are also considered to be risk factors for AD.2,7-11 An increased plasma total homocysteine (tHcy) concentration is a known risk factor for cerebrovascular disease,12 but moderately elevated levels of tHcy were also associated with confirmed AD in the Oxford Project to Investigate Memory and Ageing (OPTIMA).13 Other researchers14-17 have also found that tHcy levels were elevated in individuals with AD compared with controls.