Herrmann François R, Rodriguez Cristelle, Haller Sven, Garibotto Valentina, Montandon Marie-Louise, Giannakopoulos Panteleimon
Department of Rehabilitation and Geriatrics, Division of Geriatrics, Geneva University Hospitals and University of Geneva, Geneva, Switzerland.
Department of Psychiatry, University of Geneva, Geneva, Switzerland.
Front Aging Neurosci. 2019 Jun 28;11:157. doi: 10.3389/fnagi.2019.00157. eCollection 2019.
Cross-sectional magnetic resonance imaging (MRI) studies reported significant associations between gray matter (GM) density changes in various limbic and neocortical areas and worst cognitive performances in elderly controls. Longitudinal studies in this field remain scarce and led to conflicting data. We report a clinico-radiological investigation of 380 cognitively preserved individuals who undergo neuropsychological assessment at baseline and after 18 months. All cases were assessed using a continuous cognitive score taking into account the global evolution of neuropsychological performances. The vast majority of Mini Mental State Examination (MMSE) 29 and 30 cases showed equal or worst performance at follow-up due to a ceiling effect. GM densities, white matter hyperintensities and arterial spin labeling (ASL) values were assessed in the hippocampus, amygdala, mesial temporal and parietal cortex at inclusion using 3 Tesla MRI Scans. Florbetapir positron emission tomography (PET) amyloid was available in a representative subsample of 64 cases. Regional amyloid uptake ratios (SUVr), mean cortical SUVr values (mcSUVr) and corresponding z-scores were calculated. Linear regression models were built to explore the association between the continuous cognitive score and imaging variables. The presence of an APOE-ε4 allele was negatively related to the continuous cognitive score. Among the areas studied, significant associations were found between GM densities in the hippocampus and amygdala but not mesial temporal and parietal areas and continuous cognitive score. Neither ASL values, Fazekas score nor mean and regional PET amyloid load was related to the cognitive score. In multivariate models, the presence of APOE-ε4 allele and GM densities in the hippocampus and amygdala were independently associated with worst cognitive evolution at follow-up. Our data support the idea that early GM damage in the hippocampus and amygdala occur long before the emergence of the very first signs of cognitive failure in brain aging.
横断面磁共振成像（MRI）研究报告称，老年对照组中，各个边缘叶和新皮质区域的灰质（GM）密度变化与最差认知表现之间存在显著关联。该领域的纵向研究仍然较少，且数据相互矛盾。我们报告了一项针对380名认知功能保留个体的临床放射学调查，这些个体在基线时和18个月后接受了神经心理学评估。所有病例均使用考虑神经心理学表现整体变化的连续认知评分进行评估。由于天花板效应，绝大多数简易精神状态检查表（MMSE）评分为29分和30分的病例在随访时表现相同或更差。在纳入研究时，使用3特斯拉MRI扫描评估海马体、杏仁核、颞叶内侧和顶叶皮质的GM密度、白质高信号和动脉自旋标记（ASL）值。64例具有代表性的子样本中可获得氟代贝他吡正电子发射断层扫描（PET）淀粉样蛋白。计算区域淀粉样蛋白摄取率（SUVr）、平均皮质SUVr值（mcSUVr）和相应的z分数。建立线性回归模型以探索连续认知评分与成像变量之间的关联。APOE-ε4等位基因的存在与连续认知评分呈负相关。在所研究的区域中，发现海马体和杏仁核的GM密度与连续认知评分之间存在显著关联，但颞叶内侧和顶叶区域与连续认知评分之间无显著关联。ASL值、 Fazekas评分以及平均和区域PET淀粉样蛋白负荷均与认知评分无关。在多变量模型中，APOE-ε4等位基因的存在以及海马体和杏仁核的GM密度与随访时最差的认知演变独立相关。我们的数据支持这样一种观点，即海马体和杏仁核的早期GM损伤早在脑老化出现最初认知功能衰退迹象之前就已发生。
