Predicting Decline in Mild Cognitive Impairment

描述（由申请人提供）：轻度认知障碍（MCI）被认为是介于正常衰老和痴呆之间的中间地带，这一概念为早期识别和治疗可能发展为阿尔茨海默病（AD）的个体带来了希望。这一概念的预测价值的一个局限性是，每年只有一小部分MCI患者会发展为AD（约12%）。如果从轻度认知障碍转变为阿尔茨海默病的个体更容易识别，那么临床试验就可以更有效地进行。由于没有特定的生物医学/心理测量标记可以识别这些潜在的转化者，本研究试图利用一种新的范式来识别这些有更大风险转化为阿尔茨海默病的个体。本项目的目标之一是确定无认知障碍（NCI）或轻度认知障碍（MCI）的老年人的练习效果（即，由于反复接触测试材料而增加的认知测试表现）的相对大小。最近，实践效应已被证明在检测MCI方面是有用的，并且这些发现的一个合乎逻辑的延伸是评估他们预测MCI下降的能力。因此，第二个目标是确定练习效果在预测未来认知功能方面的相对价值。具体来说，我们建议对患有NCI或MCI的老年受试者进行纵向观察研究。所有参与者都将接受认知功能的基线评估，并将立即重复评估练习效果。预期NCI参与者比MCI参与者表现出更大的实践效应。我们还预计，在MCI群体中，一些个体会表现出相对较大的实践效果，而另一些个体则会表现出较小的实践效果。所有参与者将在6个月和12个月时进行后续认知评估。假设基线阶段的练习量与随访时认知能力下降的程度呈负相关，这可能导致更早地识别认知能力下降。

DESCRIPTION (provided by applicant): Mild Cognitive Impairment (MCI) has been proposed as a middle ground between normal aging and dementia, and this concept holds promise for the early identification and treatment of individuals likely to develop Alzheimer's disease (AD). 1 limitation of the predictive value of this concept is that only a fraction of individuals with MCI go on to develop AD each year (approximately 12%). If the individuals who convert from MCI to AD were more easily identified, then clinical trials could be more efficiently conducted. Since no specific biomedical/psychometric marker is available that identifies these potential converters, the present study seeks to utilize a novel paradigm to identify these individuals who are at greater risk to convert to AD. 1 goal of this project is to determine the relative magnitude of practice effects (i.e., increased cognitive test performance due to repeated exposure to test materials) among elderly individuals with no cognitive impairments (NCI) or MCI. Recently, practice effects have been shown to be useful in detecting MCI, and a logical extension of these findings is to evaluate their ability to predict decline in MCI. Therefore, a second goal is to determine the relative value of practice effects in predicting future cognitive functioning. Specifically, we propose a longitudinal observational study in elderly subjects with NCI or MCI. All participants will receive a baseline assessment of cognitive functioning, which will be immediately repeated to assess practice effects. It is expected that participants with NCI will demonstrate larger practice effects than participants with MCI. It is also expected that within the MCI group, some individuals will display relatively larger practice effects and some will display smaller practice effects. Follow-up cognitive evaluations will be conducted on all participants at 6- and 12-months. It is hypothesized that the amount of practice demonstrated during the baseline phase will be inversely related to the amount of cognitive decline on follow-up, which could lead to earlier identification of cognitive decline.