Title

Regional specificity of leukoaraiosis as a predictor of reduced executive monitoring abilities in the healthy elderly

Date of Completion

January 2009

Keywords

Psychology, Clinical|Psychology, Cognitive

Degree

Ph.D.

Abstract

Diminution of cerebral white matter is a common observation in the healthy elderly and often is associated with reduced cognitive performance. However, the association between regional cortical white matter abnormalities and patterns of cognitive impairment remain unclear. The current study uses structural MRI and neuropsychological tasks to examine the relationship between frontal and posterior white matter hyperintensities on neuropsychological tasks in the healthy elderly (N = 87, age 75–90 years). Age, education, and estimates of frontal white matter hyperintensity volume (WMH) predicted different patterns of performance on tasks of executive monitoring and processing speed. Age was inversely related to scores on all executive monitoring tasks, whereas education and estimates of frontal WMH were associated with two of the three executive monitoring tasks. No significant associations were observed between posterior WMH and executive monitoring or processing speed tasks. The observed dissociation between frontal and posterior areas and neuropsychological performances provides converging evidence of domain-specificity with respect to regional variations in white matter integrity. ^