The spatial distribution of age-related white matter changes as a function of vascular risk factors—Results from the LADIS study

Abstract

White matter hyperintensities (WMH) are a frequent finding on brain MRI of elderly subjects, and have been associated with various risk factors, as well as with development of cognitive and functional impairment. While an overall association between WMH load and risk factors is well described, possible spatially restricted vulnerability remains to be established. The aim of this study was to investigate the spatial distribution of WMH in normally functioning elderly subjects. We introduce a voxel-based approach in which lesion probability is mapped as a function of clinical risk factors using logistic regression, and validate the method using simulated datasets. The method was then applied in a total of 605 participants of the LADIS study (age 74 ± 5 years, all with WMH), and the location of manually delineated WMH was investigated after spatial normalisation. Particularly strong and widespread associations were found for age, gender and hypertension. Different distribution patterns were found for men and women. Further, increased probability was found in association with self-reported alcohol and tobacco consumption, as well as in those with a history of migraine. It is concluded that the location of WMH is dependent on the risk factors involved pointing towards a regionally different pathogenesis and/or vulnerability of the white matter.