Single- and multiple-domain amnestic mild cognitive impairment: two sides of the same coin?
BACKGROUND
Amnestic mild cognitive impairment (aMCI) is considered a transition stage between normal aging and Alzheimer's disease (AD). Two main clinical subtypes of aMCI have been identified: (1) single-domain aMCI (aMCI-SD), with isolated episodic memory impairments, and (2) multiple-domain aMCI (aMCI-MD), with episodic memory impairments and deficits in one or more other cognitive domains.


OBJECTIVE
To map the pattern of gray matter (GM) atrophy associated with aMCI-SD, aMCI-MD and mild AD.


METHODS
A group of aMCI-SD, aMCI-MD characterized by executive function disorders, mild AD and cognitively unimpaired subjects underwent a comprehensive neuropsychological assessment and a high-definition MR brain scan. Voxel-based morphometry analysis was used to characterize the GM tissue loss in each patient group, and the common pattern of GM atrophy in aMCI-SD and aMCI-MD.


RESULTS
aMCI-SD and aMCI-MD are characterized by a common pattern of GM atrophy within the medial temporal cortex, predisposing to AD and correlating with the severity of verbal memory symptoms. Moreover, the pattern of GM atrophy observed in aMCI-SD, aMCI-MD and mild AD revealed that, from an anatomical point of view, these three clinical syndromes could represent three severity points along the continuum between normal aging and AD.
Brambati
Simona Maria
SM
Centre de recherche, Institut universitaire de gériatrie de Montréal, Montréal, Québec, Canada. simona.maria.brambati@umontreal.ca
Belleville
Sylvie
S
Kergoat
Marie-Jeanne
MJ
Chayer
Céline
C
Gauthier
Serge
S
Joubert
Sven
S
D000368:Aged; D000544:Alzheimer Disease / Q000473:pathology / Q000523:psychology; D000647:Amnesia / Q000473:pathology* / Q000523:psychology; D001284:Atrophy; D001921:Brain / Q000473:pathology; D003072:Cognition Disorders / Q000473:pathology* / Q000523:psychology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests