Differential hypometabolism patterns according to mild cognitive impairment subtypes.
OBJECTIVE
The present study investigated cerebral glucose metabolism and structural atrophy in controls and subjects with mild cognitive impairment (MCI).


METHODS
The study included 13 controls, 7 MCI subjects considered as prodromal Alzheimer's disease (MCI of the Alzheimer type, aMCI) and 7 MCI subjects having cognitive decline due to other causes, established by clinical evaluation (MCI of the non-Alzheimer type, naMCI). Glucose metabolism in the frontal, parietal and posterior cingulate cortices, the hippocampus and parahippocampal gyrus was evaluated using Statistical Parametric Mapping 2 (SPM2). Structural analysis of the whole-brain grey matter was performed with voxel-based morphometry in SPM2.


RESULTS
Significant hypometabolism was found in the medial temporal lobe in aMCI subjects compared to the controls and naMCI subjects. In addition, both the aMCI and naMCI patients had hypometabolism of the posterior cingulum relative to controls. The naMCI subjects showed atrophy of frontal and occipital areas compared to controls and aMCI patients, whereas the aMCI subjects did not show atrophy compared to the other groups.


CONCLUSIONS
aMCI subjects have reduced glucose uptake levels, particularly in areas susceptible to pathological changes in Alzheimer's disease, and the changes are more pronounced in aMCI than naMCI subjects. Our results also suggest that functional changes may be more prominent than structural changes in MCI.
Jauhiainen
Anne M
AM
Unit of Neurology, Institute of Clinical Medicine, Mediteknia, Kuopio, Finland.
Kangasmaa
Tuija
T
Rusanen
Minna
M
Niskanen
Eini
E
Tervo
Susanna
S
Kivipelto
Miia
M
Vanninen
Ritva L
RL
Kuikka
Jyrki T
JT
Soininen
Hilkka
H
D000368:Aged; D000369:Aged, 80 and over; D001923:Brain Chemistry / Q000502:physiology*; D003072:Cognition Disorders / Q000145:classification* / Q000378:metabolism* / Q000473:pathology; D015331:Cohort Studies; D003627:Data Interpretation, Statistical; D005260:Female; D005947:Glucose / Q000378:metabolism; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007700:Kinetics; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography
D005947:Glucose