Language Disorders Due to Fiber Tract Disconnection in Aphasic Patients

描述（由申请人提供）： 日常生活中语言的使用需要大脑多个区域的参与，以及连接它们的错综复杂的纤维通路网络。语言和语言障碍的研究主要集中在这些皮层区域在支持语音和语言功能方面的贡献，而在语言处理中可能发挥重要作用的潜在神经束的作用在很大程度上是未知的。虽然已经描述了一些“断开”综合征，但对大脑中一些主要纤维束的损伤结果尚未进行充分研究。这主要是由于难以用传统的神经成像工具分离这些神经束，从而识别那些已经受损的神经束。此外，招募大量脑损伤患者样本以获得必要的成像和行为数据需要大量的时间和资源。该项目的目标是通过检查对这些通路的损害的影响来评估必须在语言处理中发挥作用的大脑主要通路的贡献。这将通过对60名患有中风失语症的慢性脑损伤患者进行广泛评估来完成，我们的失语症和相关疾病中心的工作人员将对他们的语言和神经心理缺陷进行彻底评估。我们将采用最新的脑纤维通路成像技术，使用弥散张量成像（DTI）和弥散频谱成像（DSI）对这些患者进行脑纤维通路成像，获得束完整性的测量结果，并进行纤维束成像，使每个患者的实际纤维通路可视化。这些行为数据，DTI和DSI结果从相同的患者，以及基于体素的病变-症状映射（VLSM）分析的结合使用将使我们能够最好地评估这些通路在语言功能中的作用。了解脑损伤对语言系统的影响是准确诊断和治疗影响我们退伍军人患者的语言障碍的关键。了解皮层和底层纤维束的损伤如何影响语言的不同组成部分，可以帮助临床医生，患者和护理人员了解损伤对患者沟通技能的影响。不同的疾病需要不同的治疗方法，因此更准确的诊断自然会带来更有效的补救措施。我们已经看到，不能被替代的皮质区损伤对治疗的反应与可能被环绕的纤维束损伤不同。随着VA医疗机构患者的神经影像学数据现在常规可用，从该项目中收集的信息可以直接应用于我们服务的退伍军人患者，从而为他们提供最佳的诊断和康复护理，更不用说希望更好地恢复。 公共卫生相关性： 脑损伤在我们的退伍军人患者中非常常见，其不幸的后果之一可能是影响人们沟通的言语和语言技能（失语症）的中断。虽然一些研究致力于了解这些问题以及它们与大脑不同部位损伤的关系，但很少有人了解语言技能如何受到连接这些大脑区域的纤维通路损伤的影响。这项研究将使用最先进的大脑成像工具来了解纤维束通路损伤后沟通技能如何受到影响，以及这种损伤如何与大脑的其他部分相互作用。这些信息为临床医生提供了最好的信息，临床医生的使命是为我们的退伍军人患者提供最准确的诊断和最有效的治疗。这些知识也有助于我们的患者和他们的护理人员了解伤害，以及他们如何最好地科普他们沟通能力的变化。

DESCRIPTION (provided by applicant): PROJECT SUMMARY/ABSTRACT The use of language in everyday life requires the participation of numerous regions of the brain as well as the intricate web of fiber pathways that connect them. The study of language and language disorders has largely focused on the contributions of these cortical regions in supporting speech and language functions, while the role of the underlying tracts, which could play a major role in language processing is largely unknown. While some "disconnection" syndromes have been described, the result of injury to some of the major fiber tracts in the brain has not been well studied. This has been due primarily to the difficulty in isolating these tracts with traditional neuroimaging tools, thus identifying those tracts that have been damaged over those that have been spared. In addition, recruiting the large sample of brain-injured patients required to obtain both the necessary imaging and behavioral data takes a great deal of time and resources. The goal of this project is to evaluate the contributions of major pathways of the brain that must play a role in language processing by examining the effects of damage to these pathways. This will be done through extensive evaluation of 60 chronic brain-injured patients with aphasia due to stroke, whose language and neuropsychological deficits will be thoroughly evaluated by our staff at the Center for Aphasia and Related Disorders. We will employ the latest techniques in imaging the fiber pathways of the brain, using diffusion tensor imaging (DTI) and diffusion spectrum imaging (DSI) with these patients to image the fiber pathways of the brain, obtain measurements of tract integrity, and perform tractography that visualizes the actual fiber pathways in each patient. The combined use of these behavioral data, the DTI and DSI results from the same patients, as well as voxel-based lesion-symptom mapping (VLSM) analyses will allow us the best possible evaluation of the role of these pathways in language functioning. Understanding the effects of brain injury to the language system is key to the accurate diagnosis and treatment of the language disorders that affect our veteran patients. Knowing how lesions to the cortex and to the underlying fiber tracts each affect the different components of language can help clinicians, patients and caregivers to understand the effect the injury has had on the patient's communication skills. Different disorders require different treatments, and thus more accurate diagnoses naturally lead to more effective remediation. We have already seen that damage to cortical areas, that cannot be replaced, responds differently to treatment than does damage to a fiber tract that can potentially be circumnavigated. With neuroimaging data now routinely available on patients in VA medical facilities, the information gleaned from this project can be applied directly to the veteran patients we serve, thus providing them with the optimum in diagnostic and rehabilitative care, not to mention hope for a better recovery. PUBLIC HEALTH RELEVANCE: PROJECT NARRATIVE Brain injury is very common in our veteran patients and one of its unfortunate consequences can be the disruption of speech and language skills (aphasia) that affect how people can communicate. While some research has been dedicated to understanding these problems and how they relate to injuries in different parts of the brain, very little has been done to understand how language skills can be affected by damage to the fiber pathways that connect these brain regions to one another. This research will use state-of-the- art brain imaging tools to understand how communication skills are affected after injury to fiber tract pathways and how this damage interacts with other parts of the brain. Such information provides the best information to clinicians whose mission is to give our veteran patients the most accurate diagnosis and most effective treatments. This knowledge also helps our patients and their caregivers to understand the injury and how they can best cope with the changes in their ability to communicate.