Cortical Brain Metabolism as Measured by Proton Spectroscopy Is Related to Memory Performance in Patients with Amnestic Mild Cognitive Impairment and Alzheimer’s Disease

Abstract

Aims: To investigate the relationship between verbal memory performance and brain metabolism as determined by proton spectroscopy (¹H-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 ¹H-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). Conclusion: Verbal learning performance is related to metabolic changes in cortical brain regions known to be involved in the neurodegenerative process of aMCI and AD.

Quantitative multivoxel proton MR spectroscopy study of brain metabolites in patients with amnestic mild cognitive impairment: a pilot study

“…Metabolite concentration of NAA was found to be significantly reduced, being tightly associated with derangement of neurometabolism, lower dendrite/axonal density, neuronal/ axonal loss, and the number of senile plaques, a marker of disease severity [38]. In our study, the bilateral deceases in NAA/Cr and NAA/MI ratios in the PCG and PWM were consistent with previous reports [12,39,40]. The exploration of other cortical areas such as in the right LN and left DT could also be of aid in improving predictions.…”

Initial phase of adaptation of Memory Alteration Test (M@T) in a Portuguese sample

“…The M@T is a new screening test with good discriminative properties for detection of A-MCI and very early AD from SMC population (Rami et al, 2010), with an administration time of 5 min (Rami et al, 2007a(Rami et al, , 2007b(Rami et al, , 2009(Rami et al, , 2010. The ROC curve analysis of the M@T-PT, comparatively to the MMSE, suggest a better diagnostic accuracy to discriminate SMC-G from A-MCI.…”

“…According to Rami et al (2007aRami et al ( , 2007b, the M@T is a good screening test that can measure early AD progression because it is associated to brain metabolism, such N-acetylaspartate (NAA) and myoinositol (mI), as obtained by proton magnetic resonance spectroscopy.…”

Metabolite Investigation in Both Anterior and Posterior Cingulate Gyri in Alzheimer’s Disease Spectrum Using 3-Tesla MR Spectroscopy

“…It has received much attention due to its involvement in early AD [6,7]. Metabolic changes in the posterior cingulate gyrus in MR spectroscopy have been reported in mild cognitive impairment (MCI) and early AD by numerous researchers and these changes have been shown to correlate with the severity of cognitive decline [8]. The anterior cingulate gyrus is known to be an area associated with the behavioral and psychological symptoms (BPS) of AD.…”