Cortical brain metabolism as measured by proton spectroscopy is related to memory performance in patients with amnestic mild cognitive impairment and Alzheimer's disease.
OBJECTIVE
To investigate the relationship between verbal memory performance and brain metabolism as determined by proton spectroscopy ((1)H-MRS) in selected cortical brain regions. To characterize metabolite abnormalities across the continuum of degenerative disease from mild impairment to dementia.


METHODS
27 controls, 27 amnestic mild cognitive impairment (aMCI) patients and 35 Alzheimer's disease (AD) patients. Verbal memory was assessed with the Text Memory Test, the Wordlist Learning Test (WL-Learning Test), and with a memory screening test, the Memory Alteration Test (M@T). Single-voxel (1)H-MRS was obtained in the posterior cingulate (P-CING), left temporal pole (L-TPOLE) and left posterior temporoparietal region (L-TPAR).


RESULTS
WL-Learning Test scores were inversely associated with myoinositol/creatine ratios (mI/Cr) in the L-TPAR (r = -0.404, p < 0.002). Negative associations were also observed between M@T global scores and mI/Cr in the P-CING (r = -0.42; p < 0.001), L-TPOLE (r = -0.34; p < 0.005) and L-TPAR (r = -0.46; p < 0.001). A positive association was found between M@T scores and N-acetylaspartate concentrations in the P-CING (r = 0.33; p < 0.003).


CONCLUSIONS
Verbal learning performance is related to metabolic changes in cortical brain regions known to be involved in the neurodegenerative process of aMCI and AD.
Rami
L
L
Department of Neurology, Institute of Neurosciences, Hospital Clinic i Universitari de Barcelona, Barcelona, Spain.
Gómez-Ansón
B
B
Bosch
B
B
Sánchez-Valle
R
R
Monte
G C
GC
Villar
A
A
Molinuevo
J L
JL
D000368:Aged; D000544:Alzheimer Disease / Q000378:metabolism* / Q000523:psychology; D000647:Amnesia / Q000150:complications / Q000378:metabolism* / Q000523:psychology; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D002540:Cerebral Cortex / Q000378:metabolism*; D003072:Cognition Disorders / Q000150:complications / Q000378:metabolism* / Q000523:psychology; D003401:Creatine / Q000378:metabolism; D005260:Female; D006179:Gyrus Cinguli / Q000378:metabolism; D006801:Humans; D007294:Inositol / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008568:Memory; D010296:Parietal Lobe / Q000378:metabolism; D011522:Protons; D011581:Psychological Tests; D012720:Severity of Illness Index; D013702:Temporal Lobe / Q000378:metabolism
D011522:Protons; D001224:Aspartic Acid; D007294:Inositol; C000179:N-acetylaspartate; D003401:Creatine