Correlation between cognitive deficits and glucose hypometabolism in mild cognitive impairment.
BACKGROUND
In patients with mild cognitive impairment (MCI), poor performances on delayed recall and executive function are risk factors of progression to dementia. The aim of the present study was to clarify neural correlates of these neuropsychological deficits.


METHODS
Thirty patients with amnestic MCI and 15 control subjects underwent neuropsychological tests including three-word delayed recall, visual delayed recall of Rey complex figure (RCF), and two-relational reasoning of Raven's colored progressive matrices (RCPM) with a (18)F-fluorodeoxyglucose (FDG)-position emission tomography (PET) measurement of resting state. We evaluated a relationship between performance of neuropsychological tests and regional cerebral glucose metabolism using voxel-based analysis.


RESULTS
Poor performance in three-word delayed recall was related to glucose hypometabolism in the right medial temporal, right prefrontal, and left superior parietal cortices. The deficit in visual delayed recall of RCF correlated positively with hypometabolism in the bilateral posterior cingulate. The impairment in two-relational reasoning was associated with hypometabolism in the right prefrontal cortex.


CONCLUSIONS
The present findings suggest that hypometabolism in the right medial temporal cortex, right prefrontal cortex, left superior parietal cortex, and bilateral posterior cingulate reflects impairments in delayed recall while hypometabolism in the right prefrontal cortex mirrors deficits in executive function in MCI.
Nishi
Hiroko
H
Human Brain Research Center, Kyoto University Graduate School of Medicine, Shogoin, Sakyo-Ku, Kyoto, Japan.
Sawamoto
Nobukatsu
N
Namiki
Chihiro
C
Yoshida
Hidefumi
H
Dinh
Ha Duy Thuy
HD
Ishizu
Koichi
K
Hashikawa
Kazuo
K
Fukuyama
Hidenao
H
D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D001931:Brain Mapping; D003072:Cognition Disorders / Q000000981:diagnostic imaging / Q000378:metabolism*; D056344:Executive Function / Q000502:physiology*; D005260:Female; D019788:Fluorodeoxyglucose F18; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D016014:Linear Models; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D014796:Visual Perception / Q000502:physiology
D019788:Fluorodeoxyglucose F18; D005947:Glucose