Department of Radiology, Mayo Clinic, Rochester, MN, USA.
Neurology. 2013 Jul 9;81(2):126-33. doi: 10.1212/WNL.0b013e31829a3329. Epub 2013 Jun 12.
To investigate MRI and proton magnetic resonance spectroscopy (MRS) predictors of mild cognitive impairment (MCI) in cognitively normal older adults.
Subjects were cognitively normal older adults (n = 1,156) who participated in the population-based Mayo Clinic Study of Aging MRI/MRS study from August 2005 to December 2010 and had at least one annual clinical follow-up. Single-voxel MRS was performed from the posterior cingulate gyri, and hippocampal volumes and white matter hyperintensity volumes were quantified using automated methods. Brain infarcts were assessed on MRI. Cox proportional hazards regression, with age as the time scale, was used to assess the effect of MRI and MRS markers on the risk of progression from cognitively normal to MCI. Linear mixed-effects models were used to assess the effect of MRI and MRS markers on cognitive decline.
After a median follow-up of 2.8 years, 214 participants had progressed to MCI or dementia (estimated incidence rate = 6.1% per year; 95% confidence interval = 5.3%-7.0%). In univariable modeling, hippocampal volume, white matter hyperintensity volume, and N-acetylaspartate/myo-inositol were significant predictors of MCI in cognitively normal older adults. In multivariable modeling, only decreased hippocampal volume and N-acetylaspartate/myo-inositol were independent predictors of MCI. These MRI/MRS predictors of MCI as well as infarcts were associated with cognitive decline (p < 0.05).
Quantitative MRI and MRS markers predict progression to MCI and cognitive decline in cognitively normal older adults. MRS may contribute to the assessment of preclinical dementia pathologies by capturing neurodegenerative changes that are not detected by hippocampal volumetry.
探究磁共振成像（MRI）和质子磁共振波谱（MRS）预测认知正常老年人轻度认知障碍（MCI）的指标。
本研究对象为参加 2005 年 8 月至 2010 年 12 月基于人群的梅奥诊所老龄化 MRI/MRS 研究且至少每年进行一次临床随访的认知正常老年人（n=1156）。从后扣带回获取单体素 MRS，使用自动方法量化海马体体积和脑白质高信号体积。MRI 评估脑梗死。使用 Cox 比例风险回归（以年龄为时间尺度）评估 MRI 和 MRS 标志物对从认知正常进展为 MCI 的风险的影响。使用线性混合效应模型评估 MRI 和 MRS 标志物对认知衰退的影响。
在中位数为 2.8 年的随访期间，214 名参与者进展为 MCI 或痴呆（估计发生率为每年 6.1%；95%置信区间为 5.3%-7.0%）。在单变量模型中，海马体体积、脑白质高信号体积和 N-乙酰天冬氨酸/肌醇是认知正常老年人发生 MCI 的显著预测指标。在多变量模型中，只有海马体体积减小和 N-乙酰天冬氨酸/肌醇是 MCI 的独立预测指标。这些 MRI/MRS 预测 MCI 的指标以及脑梗死与认知衰退相关（p<0.05）。
定量 MRI 和 MRS 标志物可预测认知正常老年人向 MCI 和认知衰退的进展。MRS 可能通过捕获海马体容积检测不到的神经退行性变化，有助于评估临床前痴呆病理。
