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IC‐P‐207: WHITE MATTER HYPERINTENSITY PENUMBRA: A PASL STUDY
Author(s) -
Promjunyakul Nuttaon,
Lahna David,
Rooney William D.,
ErtenLyons Deniz,
Kaye Jeffrey,
Silbert Lisa C.
Publication year - 2014
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.2014.05.215
Subject(s) - penumbra , cerebral blood flow , white matter , fluid attenuated inversion recovery , hyperintensity , cardiology , voxel , medicine , magnetic resonance imaging , nuclear medicine , radiology , ischemia
age-related changes in FCwe subclassified the types of FC increases and decreases in a sample of cognitively healthy adults. Methods: We extracted the resting-state fMRI time series from 278 brain regions of a sample of 13 young, 13 middle-aged and 7 elderly. Correlations between all 38503 pairs of regions were calculated as estimates of FC and tested for association with age using behavioral partial least squares. The connections that were significantly and reliably associated with age were classified in six types: 1) increases in magnitude of positive correlations; 2) decreases in magnitude of negative correlations; 3) shifts from negative to positive correlations; 4) increases in magnitude of negative correlations; 5) decreases in magnitude of positive correlation; 6) shifts from positive to negative correlations. Results: 2009 connections were associated with age (permuted p1⁄40.02; correlation [95% CI] 1⁄4 0.79 [0.76-0.83]; jbootstrap ratioj 3). Most were characterized by age-related increases in magnitude of positive correlation. Shifts from negative (in the young) to positive correlation (in the old) were also very common. Fewer connections were characterized by decreased in magnitude of positive correlations (Figure). We could not find connections presenting reliable age-related increases in magnitude of anticorrelations.Conclusions:Changes of FC associated with aging are heterogeneous. Most connections presented age-related increases in FC, mainly increases in magnitude of positive correlations and also negativeto-positive shifts. Although these two types of change represent age-related increases in FC, they have different meanings. The stronger positive correlations may represent higher integration, whereas the negative-to-positive shifts may indicate a decreased ability to maintain networks in an anticorrelated state. Subclassifying the increases and decreases of FC in accordance to their pattern of change allowed a better characterization of the relationship between age and FC.