Proton Spectroscopy in Alzheimer’s Disease and Cognitive Impairment No Dementia: A Community-Based Study

Abstract

Objective: To describe the findings of proton magnetic resonance spectroscopy (¹H-MRS) in Alzheimer’s disease (AD) and cognitive impairment, no dementia (CIND) elderly from a community-based sample. Methods: Thirteen patients with AD, 12 with CIND and 15 normal individuals were evaluated. The ¹H-MRS was performed in the right temporal, left parietal and medial occipital regions studying the metabolites N-acetylaspartate (NAA), creatine (Cr), choline (Cho) and myoinositol (mI). The clinical diagnosis was based on standardized cognitive tests – MMSE and CAMDEX – and the results correlated with the ¹H-MRS. Results: Parietal Cho was higher in control individuals and lower in CIND subjects. AD and control groups were better identified by temporal and parietal mI combined with the temporal NAA/Cr ratio. CIND was better identified by parietal Cho. Conclusion: The ¹H-MRS findings confirmed the hypothesis that metabolic alterations are present since the first symptoms of cognitively impaired elderly subjects. These results suggest that combining MRS from different cerebral regions can help in the diagnosis and follow-up of community elderly individuals with memory complaints and AD.

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

“…A previous study using MR spectroscopy performed on both anterior and posterior cingulate gyri showed that the NAA/Cr and mI/Cr of posterior cingulate gyri were correlated with cognitive test scores and those of anterior cingulate gyri were correlated with BPS scores [21]. In this study, only the mI/Cr showed a significant correlation while the NAA/Cr of the posterior and the anterior cingulate gyri was not correlated with both cognitive dysfunction and BPS.…”

“…These varying results may be attributable to the different patient groups examined in each study. For example, community-based studies have shown that the NAA/Cr ratio in MCI was almost the same when compared to a normal control group [21,22]. On the other hand, a clinic-based study showed that the NAA/Cr ratio in an MCI group who became demented after a 1-year follow-up decreased when compared to a normal control group [23].…”

Advances in High-Field Magnetic Resonance Spectroscopy in Alzheimer’s Disease

“…For example, examined using levels of multiple metabolites within the same hippocampal VOI, Rupsingh et al (2011) found that the accuracy of discriminating clinical AD from HC was 71% using NAA / Cr , 80% using Glu , and 94% using a combination of the quantitative NAA / Cr , Glu , and mI [102]. Similarly, in the study by Wang and others (2009), the increased mI / NAA in AD in both hippocampal and posterior cingulate VOIs was used for AD and HC classification; a better performance was obtained than when using data from a single VOI [116], as also reported by Azevedo and colleagues (2008) using a lower field [127]. These observations linked the uneven spatial expression to progressive distortion of brain structures compromised by the disease [11], suggesting some potential of MRS-based evaluation of multiple neurochemicals, and of combining metabolite data acquired from more than one brain region.…”

“…Indeed, combining metabolite data from different VOIs can improve AD identification [116], so too with combining information of multiple metabolites [102, 127, 136]. The performance of MRS can be further improved when data are combined with multimodal neuroimaging data and clinical assessment data [128-130].…”

Nuclear Magnetic Resonance Spectroscopic Studies of Human Immunoglobulin ‘G’ in Alzheimer’s Disease

“…Azevedo, D. et.al. [37] have studied proton spectroscopy in Alzheimer's disease and cognitive impairment no dementia . They have confirmed on the basis of proton magnetic resonance spectroscopy the hypothesis metabolic alterations are present .…”