Sanders-Brown Center on Aging, College of Medicine, University of Kentucky, Lexington, KY, USA.
Department of Behavioral Science, College of Medicine, University of Kentucky, Lexington, KY, USA.
J Alzheimers Dis. 2022;88(3):1127-1135. doi: 10.3233/JAD-220294.
Global amyloid-β (Aβ) deposition in the brain can be quantified by Aβ-PET scans to support or refute a diagnosis of preclinical Alzheimer's disease (pAD). Yet, Aβ-PET scans enable quantitative evaluation of regional Aβ elevations in pAD, potentially allowing even earlier detection of pAD, long before global positivity is achieved. It remains unclear as to whether such regional changes are clinically meaningful.
Test the hypothesis that early focal regional amyloid deposition in the brain is associated with cognitive performance in specific cognitive domain scores in pAD.
Global and regional standardized uptake value ratios (SUVr) from 18F-florbetapir PET/CT scanning were determined using the Siemens Syngo.via® Neurology software package across a sample of 99 clinically normal participants with Montreal Cognitive Assessment (MoCA) scores≥23. Relationships between regional SUVr and cognitive test scores were analyzed using linear regression models adjusted for age, sex, and education. Participants were divided into two groups based on SUVr in the posterior cingulate and precuneus gyri (SUVR≥1.17). Between group differences in cognitive test scores were analyzed using ANCOVA models.
Executive function performance was associated with increased regional SUVr in the precuneus and posterior cingulate regions only (p < 0.05). There were no significant associations between memory and Aβ-PET SUVr in any regions of the brain.
These data demonstrate that increased Aβ deposition in the precuneus and posterior cingulate (the earliest brain regions affected with Aβ pathology) is associated with changes in executive function that may precede memory decline in pAD.
通过 Aβ-PET 扫描可以量化大脑中的全球淀粉样蛋白-β（Aβ）沉积，以支持或反驳临床前阿尔茨海默病（pAD）的诊断。然而，Aβ-PET 扫描能够定量评估 pAD 中的区域 Aβ 升高，这可能使 pAD 在全球呈阳性之前更早地被发现。目前尚不清楚这种区域变化是否具有临床意义。
检验以下假说，即大脑中早期的局灶性区域性淀粉样蛋白沉积与 pAD 特定认知领域评分中的认知表现有关。
使用西门子 Syngo.via® Neurology 软件包，对 99 名临床正常的蒙特利尔认知评估（MoCA）评分≥23 的参与者的 18F-氟比他滨 PET/CT 扫描进行了全局和区域性标准化摄取值比（SUVr）的测定。使用线性回归模型分析了区域性 SUVr 与认知测试评分之间的关系，该模型调整了年龄、性别和教育因素。根据后扣带回和楔前叶的 SUVr（SUVr≥1.17）将参与者分为两组。使用 ANCOVA 模型分析了两组之间的认知测试评分差异。
仅执行功能表现与楔前叶和后扣带回区域的区域性 SUVr 增加有关（p<0.05）。在大脑的任何区域，记忆与 Aβ-PET SUVr 之间均无显著相关性。
这些数据表明，楔前叶和后扣带回（最早受 Aβ 病理影响的大脑区域）中 Aβ 沉积的增加与执行功能的变化有关，而执行功能的变化可能先于 pAD 中的记忆下降。
