Adamczuk Katarzyna, De Weer An-Sofie, Nelissen Natalie, Dupont Patrick, Sunaert Stefan, Bettens Karolien, Sleegers Kristel, Van Broeckhoven Christine, Van Laere Koen, Vandenberghe Rik
Laboratory for Cognitive Neurology, KU Leuven, Belgium Alzheimer Research Centre KU Leuven, Leuven Institute of Neurodegenerative Disorders, KU Leuven, Belgium.
Laboratory for Cognitive Neurology, KU Leuven, Belgium.
Cereb Cortex. 2016 Jan;26(1):358-73. doi: 10.1093/cercor/bhu286. Epub 2014 Dec 1.
Word finding symptoms are frequent early in the course of Alzheimer's disease and relate principally to functional changes in left posterior temporal cortex. In cognitively intact older adults, we examined whether amyloid load affects the network for language and associative-semantic processing. Fifty-six community-recruited subjects (52-74 years), stratified for apolipoprotein E and brain-derived neurotrophic factor genotype, received a neurolinguistic assessment, (18)F-flutemetamol positron emission tomography, and a functional MRI of the associative-semantic system. The primary measure of amyloid load was the cerebral-to-cerebellar gray matter standardized uptake value ratio in a composite cortical volume of interest (SUVR(comp)). The primary outcome analysis consisted of a whole-brain voxelwise linear regression between SUVR(comp) and fMRI response during associative-semantic versus visuoperceptual processing. Higher activity in one region, the posterior left middle temporal gyrus, correlated positively with increased amyloid load. The correlation remained significant when only the word conditions were contrasted but not for pictures. According to a stepwise linear regression analysis, offline naming reaction times correlated positively with SUVR(comp). A binary classification into amyloid-positive and amyloid-negative cases confirmed our findings. The left posterior temporal activity increase may reflect higher demands for semantic control in the presence of a higher amyloid burden.
词汇查找症状在阿尔茨海默病病程早期很常见，主要与左侧颞叶后部皮质的功能变化有关。在认知功能正常的老年人中，我们研究了淀粉样蛋白负荷是否会影响语言和联想语义处理网络。56名从社区招募的受试者（52 - 74岁），根据载脂蛋白E和脑源性神经营养因子基因型进行分层，接受了神经语言学评估、（18）F - 氟代脱氧葡萄糖正电子发射断层扫描以及联想语义系统的功能磁共振成像。淀粉样蛋白负荷的主要测量指标是在复合皮质感兴趣体积中的脑灰质与小脑灰质标准化摄取值比值（SUVR(comp)）。主要结局分析包括在联想语义处理与视觉感知处理过程中，对SUVR(comp)和功能磁共振成像反应进行全脑体素级线性回归分析。一个区域（左侧颞中回后部）的较高活动与淀粉样蛋白负荷增加呈正相关。当仅对比单词条件时，这种相关性仍然显著，但对比图片时则不然。根据逐步线性回归分析，离线命名反应时间与SUVR(comp)呈正相关。将病例分为淀粉样蛋白阳性和阴性的二元分类证实了我们的发现。左侧颞叶后部活动增加可能反映了在淀粉样蛋白负担较高的情况下对语义控制的更高需求。
