Project 1: Amyloid Imaging in Subjective Cognitive Decline

项目1：SCD摘要： 流行病学证据表明，随着年龄的增长， 赋予随后认知能力下降和/或进展为痴呆的一定程度的风险。还有 越来越多的证据表明阿尔茨海默病（AD）-生物标志物，包括β淀粉样蛋白（A β）病理学，是 与其他健康老年人的主观认知主诉相关的临床状态 主观认知能力下降（SCD）在AD研究界，对SCD的兴趣越来越大， 潜在地，AD的最早可检测的症状进一步受到越来越早的目标的推动。 在干预和二级预防试验中识别风险。然而，临床前AD的边界转移 接近正常认知老化带来了许多挑战。主观记忆的抱怨和担忧是 在老年人中很常见，甚至可能是正常的。迄今为止，我们缺乏关于如何 最好区分主观认知抱怨的病因，包括正常的认知老化。 个性特征和情绪症状的个体差异是已知的重要相关因素， 主观认知抱怨;这些心理因素如何相互作用，以及它们是否独立于 潜在的AD病理生理学尚不清楚。该项目的目标是进一步了解 关于SCD和A β病理学可能有什么联系。为了实现这一目标，我们将招募和研究56名样本 老年志愿者在医疗环境中表现出对记忆或其他认知能力的担忧， 下降，但谁也有正常的客观测试性能。我们将检验SCD是 与较高比例的A β阳性个体相关，如匹兹堡化合物B（PiB）所评估的那样， PET成像，与年龄和教育匹配的认知正常对照相比， 性问题此外，我们假设A β阳性（与A β阴性相比）SCD与1） 情绪测量变量，包括人格特质“情绪不稳定”（即，神经官能症“）， 日常生活中的情景记忆投诉和功能障碍程度;和2）其他AD生物标志物变量 反映大脑的变化，包括结构和功能MRI，以及更具有挑战性的 认知测试在可能的程度上，一个探索性的目的是比较轻度认知障碍的发生率， 通过临床核心随访，作为基线A状态的函数。本项目将提供 进一步纵向研究的基础，长期目标是确定哪些生物标志物和 SCD的心理特征是临床进展为MCI和AD的预测因素。本项目的调查结果 将进一步告知AD病理生理序列的模型， 症状变化。

Project 1: SCD Abstract: Epidemiologic evidence suggests that subjective memory complaints in aging confer some degree of risk for subsequent cognitive decline and/or progression to dementia. There is also accumulating evidence that Alzheimer Disease (AD)-biomarkers, including amyloid-beta (A�) pathology, are associated with subjective cognitive complaints in otherwise healthy older individuals a clinical state described as Subjective Cognitive Decline (SCD). In the AD research community, growing interest in SCD as potentially the earliest detectable symptoms of AD is further fueled by the goal of increasingly earlier identification of risk in intervention and secondary prevention trials. However, a boundary shift of preclinical AD closer toward normal cognitive aging poses many challenges. Subjective memory complaints and concerns are common, perhaps even normative, among older adults. To date, we lack informative data addressing how to best to distinguish among etiologies of subjective cognitive complaints, including normal cognitive aging. Individual differences in personality traits and mood symptoms are known to be important correlates of subjective cognitive complaints; how these psychological factors interact and whether they are independent of underlying AD pathophysiology is not yet understood. The goal of the proposed Project is to further knowledge about how SCD and A� pathology may be associated. To achieve this, we will recruit and study a sample of 56 older volunteers who have presented in a medical setting with concerns about memory or other cognitive decline, but who also have normal objective test performance. We will test the hypothesis that SCD is associated with a higher proportion of A�-positive individuals, as assessed by Pittsburgh compound B (PiB)- PET imaging, compared to age- and education-matched cognitively normal controls without presenting concerns. Further, we hypothesize that A�-positive (compared to A�-negative) SCD will be associated with 1) questionnaire-measured variables, including the personality trait `emotional instability (i.e.,`neuroticism'), episodic memory complaints and degree of dysfunction in daily life; and 2) other AD-biomarker variables reflective of brain changes, including structural and functional MRI, and subtle deficits on more challenging cognitive tests. To the degree possible, an exploratory aim is to compare rates of incident mild cognitive impairment (MCI) through Clinical Core follow-up, as a function of baseline A� status. This Project will provide the foundation for further longitudinal study, with the longer-term goal of determining which biomarker and psychological features of SCD are predictive of clinical progression to MCI and AD. Findings from this Project will further inform models of the AD-pathophysiological sequence in relation to very early behavioral and symptomatic change.