Language behavior and patterns of cortical atrophy in primary progressive aphasia

描述(申请人提供)：原发性进行性失语症(PPA)是一种退行性神经疾病，其特征是语言能力下降，认知的其他方面相对较少。患有PPA的人代表着一种独特的优势，可以从这一优势来检查大脑与语言的行为关系，因为皮质萎缩的区域并不局限于涉及血管损伤导致的失语的区域。本研究旨在探讨PPA中局灶性皮质萎缩模式与语言衰退之间的关系。在这项研究中，20名患有PPA的人将接受一套全面的语言单元，该单元旨在检查四个关键的语言处理领域：语义、音系学、正字法和句法。基于体素的形态测量(VBM)是一种图像分析技术，允许以体素方式比较患者与健康人的灰质体积，将用于确定区域萎缩的区域，并与20名年龄匹配的正常对照组进行比较。然后，将根据患者组中的区域灰质体积检查每个领域的行为表现。将利用全脑和感兴趣区(ROI)方法来检查萎缩与行为的关系。全脑分析将揭示每个领域中对语言处理至关重要的区域，并可能揭示参与特定语言过程的大脑区域网络。使用基于现有病变和神经成像数据创建的ROI进行分析，将揭示有行为缺陷的患者与那些在先前研究中被认为对语言至关重要的皮质区域没有缺陷的患者在灰质体积上是否存在差异。这些分析将有助于确定PPA中语言衰退的神经基础，并通过提供另一个汇聚和补充证据的来源，潜在地为当前的语言大脑-行为关系模型提供准确性。这个项目与公共卫生的相关性在于它试图澄清PPA的行为和神经变化的性质，PPA是一种研究相对较少的痴呆症变体。在PPA中寻找一致的行为-解剖关系模式是一项相对较新的努力，对于开发更好的诊断程序和为患有PPA的个人提供最佳护理至关重要。

DESCRIPTION (provided by applicant): Primary progressive aphasia (PPA) is a degenerative neurological condition characterized by a decline in language abilities, with relative sparing of other aspects of cognition. Individuals with PPA represent a unique vantage from which to examine the brain-behavior relations for language, in that areas of cortical atrophy are not confined to regions involved in aphasia resulting from vascular damage. The research proposed herein is designed to explore the relationship between patterns of regional cortical atrophy and language decline in PPA. In this study, 20 individuals with PPA will be administered a comprehensive language battery structured to examine four critical language processing domains: semantics, phonology, orthography, and syntax. Voxel-based morphometry (VBM), an image analysis technique which allows for voxel-wise comparison of gray matter volume in patients relative to healthy individuals, will be used to determine areas of regional atrophy as compared to a set of 20 age-matched normal controls. Behavioral performance in each domain will then be examined relative to regional gray matter volume in the patient group. Both whole-brain and region of interest (ROI) approaches will be utilized to examine atrophy-behavior relationships. Whole-brain analysis will reveal areas critical to language processing in each domain, and possibly networks of brain regions involved in certain language processes. Analysis using ROIs created on the basis of existing lesion and neuroimaging data will reveal whether patients with behavioral deficits differ in gray matter volume from those without deficits in cortical areas identified as critical to language in previous research. These analyses will help to identify the neural bases for language decline in PPA as well as potentially lend veracity to current models of brain-behavior relations for language by providing an additional source of converging and complementary evidence. The relevance of this project to public health lies in its attempts to clarify the nature of behavioral and neurological changes in PPA, a relatively understudied variant of dementia. The search for consistent patterns of behavioral-anatomical relationships in PPA is a relatively new endeavor and one that is critical to the development of better diagnostic procedures and provision of the best care for individuals with the disorder.