Cortical and subcortical chemical pathology in Alzheimer's disease as assessed by multislice proton magnetic resonance spectroscopic imaging

Abstract

This 1H-MRSI study of AD patients shows a regional pattern of neuronal damage in the associative cortices, as revealed by significant reduction of NA/Cre in the FC, TC, and PC, and regional derangement of phospholipid metabolism, as revealed by significant reduction of Cho/Cre in the WM.

Ways toward an early diagnosis in Alzheimer's disease: The Alzheimer's Disease Neuroimaging Initiative (ADNI)

“…An increased choline signal, a marker for membrane integrity, has also been described in AD patients, but is not found consistently [81]. Significant NAA reductions were found in the hippocampus, posterior cingulate, and gray matter of the temporal, parietal, and sometimes the occipital and frontal lobes [82][83][84][85][86][87][88][89]. The degree of cognitive impairment was found to be well correlated with the degree of NAA decrease [90].…”

Regional metabolic patterns in mild cognitive impairment and Alzheimer’s disease

“…Although probable AD patients had higher Cho /Cr ratios compared to MCI patients with TE= 30 ms., this difference did not reach statistical significance with TE= 135 ms. To our knowledge, there is no directly comparable published data that addresses 1 H MRS findings in the same group of AD subjects with different echo times in the posterior cingulate gyri. Some studies have found elevated and some comparable or depressed Cho /Cr ratios in AD patients relative to elderly controls [8][9][10][11][12][13][14][15] . The disagreement in the literature on this point may depend not only on the clinical heterogeneity of the patients and sampling of different regions in the brain, but also on the echo times used.…”

“…A recent study with single photon emission tomography (SPECT) showed a decline in blood perfusion in the hippocampal-amygdaloid complex, anterior thalamus and cingulate gyrus in both preclinical and early AD 6 . 1 H magnetic resonance spectroscopy ( 1 H MRS) studies reveal a decrease in N-acetylaspartate (NAA) and an increase in myoinositol (MI) peak contents in the brains of AD patients [7][8][9][10][11][12][13][14][15] . NAA is a neuronal marker and a decrease in its concentration suggests neuronal loss or dysfunction 16,17 .…”

Regional metabolite concentrations in human brain as determined by quantitative localized proton MRS

“…Confirming previous studies using both single-voxel MRS (3,4,6) and spectroscopic imaging (8, g), cortical gray matter contains the lowest Cho concentrations, whereas cerebellar levels are by a factor of 2-2.5 higher. In addition to these differences between tissues, there exists a strong caudal gradient of decreasing Cho in White matter parietal n = 8 (35,36) from frontal to posterior paramedian gray matter. It may be argued that the observed Cho gradient in gray matter is partly due to different partial volume effects with white matter showing higher Cho concentrations.…”