Global and local gray matter loss in mild cognitive impairment and Alzheimer's disease.
OBJECTIVE
Mild cognitive impairment (MCI) is thought to be the prodromal phase to Alzheimer's disease (AD). We analyzed patterns of gray matter (GM) loss to examine what characterizes MCI and what determines the difference with AD.


METHODS
Thirty-three subjects with AD, 14 normal elderly controls (NCLR), and 22 amnestic MCI subjects were included and underwent brain MR imaging. Global GM volume was assessed using segmentation and local GM volume was assessed using voxel-based morphometry (VBM); VBM was optimized for template mismatch and statistical mass.


RESULTS
AD subjects had significantly (12.3%) lower mean global GM volume when compared to controls (517 +/- 58 vs. 590 +/- 52 ml; P < 0.001). Global GM volume in the MCI group (552 +/- 52) was intermediate between these two: 6.2% lower than AD and 6.5% higher than the controls but not significantly different from either group. VBM showed that subjects with MCI had significant local reductions in gray matter in the medial temporal lobe (MTL), the insula, and thalamus compared to NCLR subjects. By contrast, when compared to subjects with AD, MCI subjects had more GM in the parietal association areas and the anterior and the posterior cingulate.


CONCLUSIONS
GM loss in the MTL characterizes MCI, while GM loss in the parietal and cingulate cortices might be a feature of AD.
Karas
G B
GB
Department of Diagnostic Radiology, Vrije Universiteit Medical Center, Amsterdam, The Netherlands. GB.Karas@vumc.nl
Scheltens
P
P
Rombouts
S A R B
SA
Visser
P J
PJ
van Schijndel
R A
RA
Fox
N C
NC
Barkhof
F
F
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000473:pathology*; D000647:Amnesia / Q000473:pathology; D001284:Atrophy / Q000473:pathology; D001921:Brain / Q000473:pathology*; D001931:Brain Mapping; D003072:Cognition Disorders / Q000473:pathology*; D005260:Female; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged