Imaging Brain Function/Structure in Presymptomatic FTD

描述（由申请人提供）：额颞叶痴呆（FTD）仅占所有痴呆的10-20%，但由于与阿尔茨海默病（AD）相比，其发病年龄更早，并且其特征攻击核心人类品质，例如同情心，洞察力和语言沟通，因此在临床上仍然很重要。与阿尔茨海默病一样，在潜在病理的早期阶段治疗FTD比在症状出现和恶化的晚期治疗更有可能成功。在这些症状出现之前，需要检测大脑病理，以便开发和评估这些治疗方法。我们建议使用功能和结构磁共振成像（MRI）来检测没有痴呆症状但注定会发展为FTD的人的脑网络功能改变，以及额叶和前颞叶皮质密度的细微变化。在与FTD、骨佩吉特病和包涵体肌病相关的9号染色体上含有valosin-containing protein （VCP）基因突变的确定受试者中，发生FTD的可能性很高。这些人将接受测试，以确保没有FTD的症状和典型的认知障碍。突变携带者将与同一家族的非携带者进行比较。第一个具体目标是进行功能性MRI研究，以测量在标准工作记忆和字母流畅性任务中额叶和顶叶的激活，这些任务通常在早期FTD症状患者中表现不佳。我们还将执行一项对照对抗命名任务，在初步研究中显示，在VCP突变携带者和非携带者中，激活后颞和枕区的区域相同。这些数据将使用先进的分析和统计技术、判别分析和分层聚类来分析，以确定最有可能发展为未来痴呆症的携带者。第二个目的是比较VCP突变携带者和非携带者之间的三维结构图像测量的区域皮质密度。我们将把功能和结构测量与认知测试结果结合起来，完善我们对痴呆症的预测模型。这些基础研究有望证明在严格定义的症状前FTD中大脑网络功能改变和区域皮质密度下降。

DESCRIPTION (provided by applicant): Frontotemporal dementia (FTD) represents only 10-20% of all dementias, but remains important clinically because of its earlier age of onset compared to Alzheimer's disease (AD), and its characteristic attack on core human qualities ,e.g..compassion, insight and verbal communication. Treatment of FTD, as in AD, is more likely to succeed when applied in the early stages of the underlying pathology than in later stages, when symptoms appear and worsen. Detection of brain pathology is needed prior to these symptoms in order to develop and evaluate such treatments. We propose to use functional and structural magnetic resonance imaging (MRI) to detect brain network functional alterations, and subtle changes in cortical density in the frontal and anterior temporal lobes, in persons without dementia symptoms, but who are destined to develop FTD. The high likelihood of developing FTD is well-defined in identified subjects with mutations in the valosin-containing protein (VCP) gene on chromosome 9 associated with FTD, Paget's disease of bone, and inclusion-body myopathy. These persons will be tested to insure the absence of symptoms and typical cognitive impairments in FTD. Mutation carriers will be compared to non-carrier members of the same families. The first specific aim is to perform functional MRI studies to measure frontal and parietal activation during standard working memory and letter fluency tasks typically performed poorly in persons with early symptoms of FTD. We will also perform a control confrontation naming task, shown in preliminary studies to activate regions of the posterior temporal and occipital regions equally in VCP mutation carriers and in non-carriers. These data will be analyzed using advanced analytical and statisitical techniques, discriminant analysis and hierarchical clustering, to identify carriers most likely to develop future dementia. The second specific aim is to compare regional cortical density measured from three-dimensional structural images between VCP mutation carriers and non-carriers. We will combine the functional and structural measures with cognitive test results to refine our predictive model for dementia. These fundamental studies are expected to demonstrate brain network functional alterations and regionally decreased cortical density in rigorously-defined presymptomatic FTD.