Decreased N-Acetyl Aspartate/Myo-Inositol Ratio in the Posterior Cingulate Cortex Shown by Magnetic Resonance Spectroscopy May Be One of the Risk Markers of Preclinical Alzheimer's Disease: A 7-Year Follow-Up Study.
Decreased N-Acetyl Aspartate/Myo-Inositol Ratio in the Posterior Cingulate Cortex Shown by Magnetic Resonance Spectroscopy May Be One of the Risk Markers of Preclinical Alzheimer's Disease: A 7-Year Follow-Up Study.
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DOI：
10.3233/jad-170450
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Nojo T
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文献类型：
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作者：
Waragai M;Moriya M;Nojo T
尽管淀粉样蛋白和tau蛋白的分子正电子发射断层扫描成像可以促进临床前阿尔茨海默病（AD）病理的检测，但其在临床实践中并不有用。临床前AD的更实用的替代标记物将提供有价值的工具。因此，我们试图验证常规磁共振波谱（MRS）作为临床前AD筛查方法的实用性。共有289名在基线时认知正常的老年参与者进行了为期7年的临床随访，以分析MRS代谢产物，包括后扣带回皮质（PCC）中的N-乙酰天冬氨酸（NAA）和肌醇（MI）。基线7年后，289名参与者被回顾性地分为五组：200名（69%）认知功能保持正常; 53名（18%）出现轻度认知障碍（MCI）; 21名（7%）出现AD;八名（2%）出现认知正常的帕金森病，七名（2%）出现路易体痴呆症（DLB）。与从基线到基线后7年保持正常认知的参与者相比，AD、MCI和DLB组PCC的NAA/MI比值显著降低。基线后7年MMSE评分与PCC中MI/Cr和NAA/MI比值显著相关。这些结果表明，认知功能正常的老年受试者低NAA/MI的比例在PCC可能有进展为临床AD的风险。因此，常规1HMRS检测PCC中NAA/MI比值可作为临床前AD的一个筛选指标。
Although molecular positron emission tomography imaging of amyloid and tau proteins can facilitate the detection of preclinical Alzheimer’s disease (AD) pathology, it is not useful in clinical practice. More practical surrogate markers for preclinical AD would provide valuable tools. Thus, we sought to validate the utility of conventional magnetic resonance spectroscopy (MRS) as a screening method for preclinical AD. A total of 289 older participants who were cognitively normal at baseline were clinically followed up for analysis of MRS metabolites, including N-acetyl aspartate (NAA) and myo-inositol (MI) in the posterior cingulate cortex (PCC) for 7 years. The 289 participants were retrospectively divided into five groups 7 years after baseline: 200 (69%) remained cognitively normal; 53 (18%) developed mild cognitive impairment (MCI); 21 (7%) developed AD; eight (2%) developed Parkinson’s disease with normal cognition, and seven (2%) developed dementia with Lewy bodies (DLB). The NAA/MI ratios of the PCC in the AD, MCI, and DLB groups were significantly decreased compared with participants who maintained normal cognition from baseline to 7 years after baseline. MMSE scores 7 years after baseline were significantly correlated with MI/Cr and NAA/MI ratios in the PCC. These results suggest that cognitively normal elderly subjects with low NAA/MI ratios in the PCC might be at risk of progression to clinical AD. Thus, the NAA/MI ratio in the PCC measured with conventional 1H MRS should be reconsidered as a possible adjunctive screening marker of preclinical AD in clinical practice.