Topographical patterns of lobar atrophy in frontotemporal dementia and Alzheimer's disease.
OBJECTIVE
Fronto-temporal dementia (FTD) designates a group of relatively common neurodegenerative disorders. The aim of this study was to characterize the patterns of brain atrophy in FTD compared to Alzheimer's disease (AD).


METHODS
A novel semiautomatic volumetric MRI analysis method was applied to measure regional brain volumes in FTD (n = 15; behavioural variant n = 9, language variant n = 6) in contrast with AD patients (n = 15) and age-matched controls (NC) (n = 15). FTD and AD patients were matched on demographic measures and Mini Mental State Examination scores.


RESULTS
Significant atrophy was present in the frontal and anterior temporal lobes of subjects with FTD compared to AD (p = 0.02; effect size = 1.11) and compared to NC (p < 0.001; effect size = 1.86). Severe atrophy of the left anterior temporal region distinguished the language variant. AD patients, by contrast, did not differ from NC for frontal lobe volume but had smaller anterior temporal lobes (p = 0.03). Both dementia groups had medial temporal lobe atrophy of similar magnitude. A logistic regression model including 4 regional measures correctly classified 100% of subjects.


CONCLUSIONS
FTD can be reliably differentiated from AD by virtue of a topographical pattern of atrophy involving the frontal lobes and anterior temporal regions. Medial temporal lobe volumes do not distinguish FTD from AD.
Division of Neurology, Department of Medicine, Maisonneuve-Rosemont Hospital, Université de Montréal, Canada. cbocti@gmail.com
Christian
C
Bocti
Conrad
C
Rockel
Peter
P
Roy
Fuqiang
F
Gao
Sandra E
SE
Black
D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000473:pathology*; D001284:Atrophy / Q000473:pathology; D001931:Brain Mapping / Q000379:methods*; D003072:Cognition Disorders / Q000175:diagnosis; D003704:Dementia / Q000175:diagnosis* / Q000473:pathology*; D005260:Female; D005625:Frontal Lobe / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009410:Nerve Degeneration / Q000473:pathology; D009483:Neuropsychological Tests; D012720:Severity of Illness Index; D013702:Temporal Lobe / Q000473:pathology*