White matter tract integrity in aging and Alzheimer's disease.
The pattern of degenerative changes in the brain white matter (WM) in aging, mild cognitive impairment (MCI), and Alzheimer's disease (AD) has been under debate. Methods of image analysis are an important factor affecting the outcomes of various studies. Here we used diffusion tensor imaging (DTI) to obtain fractional anisotropy (FA) measures of the WM in healthy young (n = 8), healthy elderly (n = 22), MCI (n = 8), and AD patients (n = 16). We then applied "tract-based spatial statistics" (TBSS) to study the effects of aging, MCI, and AD on WM integrity. Our results show that changes in WM integrity (that is, decreases in FA) are different between healthy aging and AD: in healthy older subjects compared with healthy young subjects decreased FA was primarily observed in frontal, parietal, and subcortical areas whereas in AD, compared with healthy older subjects, decreased FA was only observed in the left anterior temporal lobe. This different pattern of decreased anatomical connectivity in normal aging and AD suggests that AD is not merely accelerated aging.
Damoiseaux
Jessica S
JS
Department of Neurology, VU University Medical Center, Amsterdam, The Netherlands. J.Damoiseaux@vumc.nl
Smith
Stephen M
SM
Witter
Menno P
MP
Sanz-Arigita
Ernesto J
EJ
Barkhof
Frederik
F
Scheltens
Philip
P
Stam
Cornelis J
CJ
Zarei
Mojtaba
M
Rombouts
Serge A R B
SA
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology*; D000544:Alzheimer Disease / Q000473:pathology*; D016880:Anisotropy; D001288:Attention / Q000502:physiology; D001921:Brain / Q000473:pathology*; D001931:Brain Mapping; D003072:Cognition Disorders / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D009483:Neuropsychological Tests; D011340:Problem Solving / Q000502:physiology; D013223:Statistics as Topic; D055815:Young Adult