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P2–146: Evaluation of common changes in the aging brain: Comparing high‐ and low‐field MRI
Author(s) -
Song Xiaowei,
Guo Hui,
Zhang Yunting,
Rockwood Kenneth
Publication year - 2013
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2013.05.790
Subject(s) - atrophy , neuroimaging , white matter , hyperintensity , medicine , psychology , fluid attenuated inversion recovery , alzheimer's disease neuroimaging initiative , magnetic resonance imaging , alzheimer's disease , nuclear medicine , neuroscience , disease , radiology
Background:White matter hyperintensities (WMH) on brain magnetic resonance imaging (MRI) are common in aging, yet their relation to cognition in individuals without overt cognitive impairment is unclear. The aim of this study was to examine the relation of total WMH volume to function in different cognitive systems in older community-dwelling individuals without dementia or mild cognitive impairment. Methods: We used data from women and men enrolled in an epidemiologic study of aging, the Memory and Aging Project. Cognitive data included composite measures of five different cognitive systems and global cognition, based on 19 individual tests. Brain MRI data were available in 285 subjects without dementia or mild cognitive impairment (mean age 1⁄481 years and education 1⁄415 years; 75% women). WMH were automatically segmented based on both T 2 weighted FLAIR and T 1 -weighted MPRAGE data. Total WMH volume was measured for each participant. Linear regression analyses, adjusted for demographic and other variables, were used to examine the relation of logarithmically-transformed total WMH volume, normalized by intracranial volume, to global cognition and to cognition in five different cognitive domains.Results:Most individuals had someWMHandWMHvolumewas associated with age (r s 1⁄40.41; p <0.001). In a linear regression model adjusted for age, sex, and education, larger WMH volumes were associated with lower levels of global cognitive function (estimate 1⁄4 -0.170, SE1⁄40.057; p1⁄40.003). In a series of adjusted analyses of different cognitive systems, largerWMH volumes were associated with lower perceptual speed (estimate1⁄4 -0.470, SE 1⁄40.094; p <0.001) and semantic memory (estimate 1⁄4 -0.153, SE 1⁄40.076; p 1⁄4 0.046), but not with episodic memory, working memory, or visuospatial abilities (all p >0.14). There was no evidence for effect modification by age, ApoEε4, or vascular disease. Conclusions: This study of older community-dwelling individuals without overt cognitive impairment suggests that total WMH volume is related to lower cognition, especially perceptual speed. Findings appear to be independent of age and vascular disease. Future work will need to examine mechanisms linking WMH to cognition.