Cinguloparietal atrophy distinguishes Alzheimer disease from semantic dementia.
BACKGROUND
Progressive brain atrophy is associated with Alzheimer disease (AD) and other dementias. Regional differences in brain atrophy may reflect clinical features of disease.


OBJECTIVE
To identify regions of cerebral atrophy that are associated with AD vs other dementias.


METHODS
University hospital dementia clinic.


METHODS
Eleven patients with AD and 11 with semantic dementia (SD), matched for age, sex, education, and degree of overall cognitive impairment and 15 normal controls.


METHODS
Voxel-based morphometry was used to compare patterns of gray matter loss, measured on T1-weighted magnetic resonance images, between patients with AD or SD, a subtype of frontotemporal lobar degeneration, and controls. Statistically significant differences in regional gray matter concentration, after multiple-comparisons correction, between groups of subjects were identified.


RESULTS
Patients with AD were more impaired than those with SD on tests of visuospatial function and on simple calculations. Consistent with these neuropsychological deficits, the most significant area of atrophy in the AD group was the left parietal cortex vs controls (z = 5.0; P =.04). Compared with SD, AD was associated with more atrophy in the left parietal lobe (z = 5.6; P =.04) and bilaterally in the posterior cingulate/precuneus (z = 5.1; P =.04). A discriminant function analysis demonstrated that the degree of atrophy of right posterior cingulate, left parietal lobe, right amygdala, and right anterior temporal lobe structures correctly classified 96% of the patients.


CONCLUSIONS
Alzheimer disease is associated with a specific pattern of cortical atrophy compared with SD.
Boxer
Adam L
AL
Memory and Aging Center and the Department of Neurology, University of California at San Francisco, 94143, USA. adam.boxer@memory.ucsf.edu
Rankin
Katherine P
KP
Miller
Bruce L
BL
Schuff
Norbert
N
Weiner
Michael
M
Gorno-Tempini
Maria-Luisa
ML
Rosen
Howard J
HJ
D000368:Aged; D000544:Alzheimer Disease / Q000145:classification* / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D001284:Atrophy / Q000473:pathology / Q000503:physiopathology; D001921:Brain / Q000473:pathology*; D003704:Dementia / Q000145:classification* / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011859:Radiography