Brain Activation in Humans

描述（由申请人提供）： 越来越需要证据来支持康复中的临床决策。神经影像学的进步对于支持和完善康复干预至关重要。近红外光谱（NIRS）是一种新兴的功能性神经成像技术，相对于功能性磁共振成像（fMRI）具有便携性等优点。NIRS有可能成为一种有效的神经康复结局指标。这是一种光学神经成像方式，间接监测局部波动皮质血红蛋白 氧合，其随神经活动而变化。它是便携式的，非侵入性的，并允许在自然环境中相对自由地移动。因此，近红外光谱技术是一个有用的工具来跟踪神经恢复和探索神经可塑性，如果确定是可靠和有效的。 以前的研究检查近红外光谱的可靠性报告中度到强相关性（ICC = 0.5- 0.83）与功能磁共振成像在各种人群和皮质区域。NIRS效度研究 也显示出同样强劲的结果。这些研究使用任务或刺激为基础的范例，如手部动作，言语产生或被动观察视觉刺激。 在人类神经影像学中最有前途的范例之一是研究fMRI血氧水平依赖（BOLD）信号的缓慢（< 0.1 Hz）波动。在没有明显任务的情况下，神经系统之间存在强烈的时间相关性。这种自发活动（即静息状态）是指不属于特定输入或输出的活动;它代表由大脑内在产生的活动。由于没有任务，研究可以在不愿意或不能坚持任务范式的人中进行，并且可以避免对任务表现，镜像运动，头部运动或任务策略差异的关注。静息状态的功能磁共振成像数据已被证明是非常一致的跨会话在健康个体，这意味着网络分析将是有用的纵向治疗相关的操作。 静息状态功能连接图的重复性已使用近红外光谱进行了检查。支持其效用的证据基于有限的样本量（n=5）。本研究将使用结构方程模型（SEM）来评估脑卒中患者视觉和运动网络有效连接的可靠性和可重复性。我们将检验以下假设：1）fNIRS时程在一个7分钟的疗程内和相隔7天的两个疗程之间对中风患者和健全对照者是可靠的，和2）在中风超过12个月的人中，fNIRS有效连接图和fMRI有效连接图之间存在显著关联，预期的研究结果将证实，静息态近红外光谱连接图可以可靠地获得中风的人，从而允许未来应用静息态近红外光谱提供成像指标，除了行为结果，其中竞争的治疗可以进行评估。 公共卫生相关性： 亚特兰大退伍军人康复研究和发展中心的使命是改善功能，独立性和老年退伍军人的生活质量残疾和那些获得残疾，因为他们的年龄。该使命将通过研究，旨在了解潜在的损伤和残疾的机制，并将这种理解的设计，测试和创造性的康复干预措施的评估。 绘制静息态大脑网络可以深入了解大脑的功能结构。拟议项目的广泛，长期目标是帮助监测结果，为老年退伍军人开发创造性的康复干预措施和辅助技术。如果目标是 应用的实现，我们期望发现，皮质连接地图使用FNIRS生成的中风幸存者受伤后，是可靠和有效的。预期的发现将首次使用FNIRS推进静息状态下大脑连接的科学知识。

DESCRIPTION (provided by applicant): There is a growing need for evidence to support clinical decision making in rehabilitation. Advancements in neuroimaging are essential for the support and refinement of rehabilitative interventions. Near-infrared spectroscopy (NIRS) is an emerging functional neuroimaging technique with advantages, relative to functional magnetic resonance imaging (fMRI) of portability. NIRS has the potential to be an effective neurorehabilitation outcome measure. It is an optical neuroimaging modality that indirectly monitors local fluctuations in cortical hemoglobin oxygenation, which change with neural activity. It is portable, non-invasive and allows for comparatively free movement within a natural environment. Therefore, NIRS may be a useful instrument to track neural recovery and explore neural plasticity if determined to be reliable and valid. Previous studies examining the reliability of NIRS report moderate to strong correlations (ICC = 0.5- 0.83) with fMRI in a variety of populations and cortical regions. NIRS validity studies have demonstrated equally robust results. These studies used task or stimulus-based paradigms such as hand movements, speech production or passive observation of visual stimulus. One of the most promising paradigms in human neuroimaging is the study of slow (< 0.1 Hz) fluctuations in the fMRI blood-oxygen level dependent (BOLD) signal. Strong temporal correlations among neural systems exist in the absence of an overt task. This spontaneous activity (i.e. resting state) refers to activity that is not attributable to specific inputs or oututs; it represents activity that is intrinsically generated by the brain. As there is no task, studies can e conducted in people unwilling or unable to adhere to task paradigms and may circumvent concerns about differences in task performance, mirror movement, head motion, or task strategy. Resting-state fMRI data has been shown to be remarkably consistent across session in healthy individuals, implying that network analysis would be useful in following longitudinal treatment-related manipulations. Repeatability of resting state functional connectivity maps have been examined using NIRS. Evidence to support their utility have been based upon a limited sample size (n=5). Our study will use structural equation modeling (SEM) to evaluate the reliability and repeatability in effective connectivity of the visual and motor networks in patient with stroke. We will test the hypotheses that 1) fNIRS timecourses will be reliable in people with stroke and able-bodied controls within one seven-minute session and between two sessions conducted 7 days apart, and 2) there will be significant association between the fNIRS effective connectivity maps and the fMRI effective connectivity maps in people who suffered stroke greater than 12 months and in able-bodied controls The expected findings will confirm that resting-state NIRS connectivity maps can be reliably obtained in people with stroke; thus permitting future application of resting state NIRS to provide imaging metrics, in addition to behavioral outcomes, by which competing therapies may be evaluated. PUBLIC HEALTH RELEVANCE: The mission of the Atlanta VA Rehabilitation Research and Development Center is to improve the function, independence, and quality of life of aging veterans with disabilities and those acquiring disabilities as they age. The mission will be accomplished by research directed towards understanding the mechanisms underlying impairments and disabilities, and applying this understanding to the design, testing, and evaluation of creative rehabilitative interventions. Mapping resting-state brain networks allows insight into the brain's functional architecture. The broad, long term objectives of the proposed project are to help monitor outcomes, develop creative rehabilitation interventions and assistive technologies for aging veterans. If the aims of the applications are achieved, we expect to find that cortical connectivity maps generated using FNIRS are both reliable and valid in stroke survivors post injury. The expecting findings will advance the scientific knowledge of brain connectivity during the resting state using FNIRS for the first time.