http://www.frontiersin.org/neuroscience/agingneuroscience/paper/10.3389/fnagi.2010.00024/

Vollständiger Abstract

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<h4>Introduction</h4>Normative brain metabolite references are essential for evaluating metabolic change in rehabilitation patients with stroke, traumatic brain injury, or cognitive decline. We provide preliminary, cohort-specific reference estimates in cognitively healthy older adults using proton magnetic resonance spectroscopy ( 1 H-MRS) and examine regional and age-related differences.<h4>Methods</h4>Twenty healthy older adults (10 males, 10 females; mean age 71.0 ± 9.5 years, range 56-84) underwent single-voxel <i> 1 H</i>-MRS at 3T in three regions: dorsal anterior cingulate cortex (DACC), posterior cingulate cortex (PCC), and occipital cortex (OC). A Bayesian deep-learning convolutional neural network quantified 14 metabolite ratios normalized to total creatine (<i>tCr</i>). Because regions were acquired within each participant (20 independent observations), regional differences were evaluated primarily with the within-subject Friedman test (Kendall's <i>W</i>), with Kruskal-Wallis as a secondary analysis; Benjamini-Hochberg false discovery rate (FDR) correction was applied across the 14 metabolites. Age- and MMSE-metabolite associations used Spearman's rank correlation with FDR applied both across all 42 tests and within each region.<h4>Results</h4>Nine of 14 metabolites showed significant regional differences (seven also surviving the primary Friedman test after FDR correction), with glycerophosphocholine (GPC)/tCr showing the largest effect (Friedman <i>W</i> = 0.82; Kruskal-Wallis ε 2 = 0.55). γ-aminobutyric acid (GABA)/tCr was highest in the OC, whereas myo-inositol (mI) and choline compounds were highest in the DACC. In exploratory age analyses, the PCC showed negative correlations for aspartate (Asp)/tCr (ρ = -0.61, <i>p</i> = 0.004) and glutathione (GSH)/tCr (ρ = -0.59, <i>p</i> = 0.006), both surviving region-wise FDR correction (<i>q</i> = 0.044), with glutamate (Glu)/tCr nominal (ρ = -0.45) and total N-acetylaspartate (tNAA)/tCr at trend level (ρ = -0.39); the DACC showed positive correlations for glucose (Glc)/tCr (ρ = +0.60) and lactate (Lac)/tCr (ρ = +0.50). No association survived the more conservative correction across all 42 tests. The OC showed no significant age associations.<h4>Conclusion</h4>This study established preliminary, cohort-specific multi-regional <i> 1 H</i>-MRS reference estimates for cognitively intact older adults, with robust regional profiles and large effect sizes. The PCC showed exploratory age-related change-most consistently a coordinated aspartate-glutathione decline-requiring confirmation in larger cohorts, whereas the OC emerged as a candidate metabolically stable region.

Abstract: PubMed · Datensatz