Department of Psychology, Marquette University, Milwaukee, Wisconsin, USA.
J Int Neuropsychol Soc. 2013 Jan;19(1):11-21. doi: 10.1017/S1355617712000951. Epub 2012 Nov 30.
Previous studies suggest that task-activated functional magnetic resonance imaging (fMRI) can predict future cognitive decline among healthy older adults. The present fMRI study examined the relative sensitivity of semantic memory (SM) versus episodic memory (EM) activation tasks for predicting cognitive decline. Seventy-eight cognitively intact elders underwent neuropsychological testing at entry and after an 18-month interval, with participants classified as cognitively "Stable" or "Declining" based on ≥ 1.0 SD decline in performance. Baseline fMRI scanning involved SM (famous name discrimination) and EM (name recognition) tasks. SM and EM fMRI activation, along with Apolipoprotein E (APOE) ε4 status, served as predictors of cognitive outcome using a logistic regression analysis. Twenty-seven (34.6%) participants were classified as Declining and 51 (65.4%) as Stable. APOE ε4 status alone significantly predicted cognitive decline (R(2) = .106; C index = .642). Addition of SM activation significantly improved prediction accuracy (R(2) = .285; C index = .787), whereas the addition of EM did not (R(2) = .212; C index = .711). In combination with APOE status, SM task activation predicts future cognitive decline better than EM activation. These results have implications for use of fMRI in prevention clinical trials involving the identification of persons at-risk for age-associated memory loss and Alzheimer's disease.
先前的研究表明，任务激活的功能磁共振成像（fMRI）可以预测健康老年人未来的认知能力下降。本 fMRI 研究检验了语义记忆（SM）与情景记忆（EM）激活任务预测认知能力下降的相对敏感性。78 名认知正常的老年人在入组时和 18 个月后进行了神经心理学测试，根据≥1.0 SD 的表现下降，参与者被分类为认知“稳定”或“下降”。基线 fMRI 扫描包括 SM（著名人物识别）和 EM（姓名识别）任务。使用逻辑回归分析，SM 和 EM fMRI 激活以及载脂蛋白 E（APOE）ε4 状态作为认知结果的预测因子。27 名（34.6%）参与者被分类为下降，51 名（65.4%）为稳定。APOE ε4 状态单独显著预测认知下降（R²=0.106；C 指数=0.642）。添加 SM 激活显著提高了预测准确性（R²=0.285；C 指数=0.787），而添加 EM 则没有（R²=0.212；C 指数=0.711）。结合 APOE 状态，SM 任务激活比 EM 激活更能预测未来的认知能力下降。这些结果对使用 fMRI 进行预防临床试验具有重要意义，可用于识别与年龄相关的记忆丧失和阿尔茨海默病相关的高危人群。
