MRI and Decline of Aging Aviator Performance

描述（由申请人提供）：本提案的目标是确定是否可以通过在模型中增加纵向脑容量变化的评估来改进“现实世界”认知任务中与年龄相关的衰退模型。我们将收集100多名参与我们正在进行的飞行员表现纵向研究的飞行员的纵向结构MRI数据：60名55岁或以上的受试者将在四年的时间内（Y0, Y2, Y4）进行三次扫描。一半的样本将拥有载脂蛋白E (APOE) ε 4等位基因（e4携带者），这是阿尔茨海默病的遗传风险因素。我们的主要假设是：通过纵向磁共振体积测量评估的年化萎缩率可以解释飞行模拟器性能下降率的个体差异，而不是通过处理速度和工作记忆，APOE e4载体状态和航空经验的测量来解释。我们还将研究基线MR测量是否与纵向MR测量一样有用，目的是实现早期识别有下降风险的个体。海马体和额叶的体积测量将是主要假设的MR预测指标，因为我们的观点是安全驾驶飞机到预定目的地涉及路线记忆和多任务处理技能。主要结果测量是飞行总结分数的下降率，使用高度量化的飞行模拟器测试，包括多任务处理。几年来，我们一直在量化飞行模拟器中跟踪一组老小型飞机飞行员的表现。数据清楚地显示了年龄对表现的影响；然而，随着时间的推移，飞行员的表现存在很大的异质性。我们建议通过增加高度量化的MR体积测量来增强我们的预测指标集，以更好地解释功能衰退发生在谁身上以及如何发生。

DESCRIPTION (provided by applicant): The goal of this proposal is to determine if one can improve models of age-related decline on a "real world" cognitive task by adding assessments of longitudinal brain volume changes to the model. We will collect longitudinal structural MRI data on a subset of the 100+ aviators participating in our ongoing longitudinal study of pilot performance: 60 subjects, 55 years of age or older, will be scanned three times each across a span of four years (Y0, Y2, Y4). Half of the sample will possess an Apolipoprotein E (APOE) epsilon 4 allele (e4 carriers), a genetic risk factor for Alzheimer's disease. Our primary hypotheses are: Annualized rate of atrophy, as assessed by longitudinal MR volumetric measures, can account for individual differences in the rate of decline in flight simulator performance, beyond that explained by measures of processing speed and working memory, APOE e4 carrier status, and aviation experience. We will also examine whether baseline MR measures are as useful as longitudinal MR measures, for the aim of achieving earlier identification of individuals at risk of decline. Volumetric measures of hippocampus and frontal lobe will be the MR predictors in the primary hypothesis, as our perspective is that safely flying an airplane to its intended destination involves memory for routes and multi-tasking skills. The primary outcome measure is rate of decline in flight summary scores, using a highly quantified flight simulator test involving multi-tasking. For several years we have been following a group of older small-aircraft pilots' performance in a quantified flight simulator. Data clearly show effects of age on performance; however, there is substantial heterogeneity in performance over time among aviators. We propose to enhance our set of predictors by the addition of highly quantified MR volumetric measures to better explain in whom and how functional decline occurs.