UNDERSTANDING THE EFFECTS OF STROKE USING FUNCTIONAL CONNECTIVITY MRI

描述（由申请人提供）：中风造成的行为缺陷和解剖损伤之间的关系只是部分的，因为生理功能障碍可以在远离病变的大脑区域进行测量。这些非局部生理缺陷可以使用功能连通性磁共振成像（fcMRl）来评估，该成像测量血氧水平依赖性（BOLD）信号中大脑区域之间的时间相关性。对健康成人fcMRl的研究已经确定了分布在不同行为功能（如注意力、运动控制和语言）基础上的脑网络。我们之前对空间忽视的中风患者的研究表明，注意网络中的fcMRl缺陷与患者在被忽视领域的缺陷相关。这项拨款表明，fcMRl可以更广泛地用于理解中风在行为领域产生的缺陷。我们将在一个大型的、异质的中风患者样本中测量fcMRl，并测试中风如何导致大脑网络功能障碍以及这种功能障碍如何与行为缺陷相关的几个假设。我们预测，双侧组织的运动和注意网络的半球间连通性的减少将与相应的行为缺陷相关，并且这些相关性将显示功能特异性。例如，手臂定义的运动网络内的连通性将比下肢功能更好地预测上肢功能。我们确定了在一个非对称组织的网络，语言中连通性和行为之间的相关性，并比较了半球间和半球内连通性的重要性。我们研究了多个大脑网络的功能如何相互作用以产生单一的行为缺陷，并假设一些网络的连通性，如注意力，与跨领域的行为相关。我们对fcMRl进行纵向测量，以确定连接是否在不同的网络中以不同的速率恢复，以及这种恢复是否与行为恢复相关。最后，我们研究了中风产生的连通性变化如何取决于结构受损的束的类型。公共卫生相关性：该提案的目标是了解中风对大脑生理的影响，以及它们与中风产生的行为缺陷之间的关系。我们计划用一种新颖的方法来测量中风患者的这些生理影响，这种方法将允许我们同时评估许多不同的大脑网络的功能，这些网络被认为是我们使用语言、参与环境、执行运动动作等能力的基础。我们将测量中风患者在中风后不同时间点进行这些活动的能力，使我们能够了解患者行为功能的恢复与生理功能的恢复之间的关系。

DESCRIPTION (provided by applicant): The relationship between the behavioral deficits and anatomical damage produced by a stroke is only partial, since physiological dsyfunction can be measured in brain regions far removed from the lesion. These non-local physiological deficits can be assessed using functional connectivity magnetic resonance imaging (fcMRl), which measures the temporal correlation between brain regions in the blood-oxygenation-level-dependent (BOLD) signal. Studies of fcMRl in healthy adults have identified distributed brain networks that underlie different behavioral functions, such as attention, motor control, and language. Our previous work on stroke patients with spatial neglect has shown that fcMRl deficits within the attention network correlate with a patient's deficit in the neglected field. This grant proposes that fcMRl can be used more broadly to understand the deficits produced by stroke across behavioral domains. We will measure fcMRl in a large, heterogeneous sample of stroke patients, and test several hypotheses of how strokes produce dysfunction in brain networks and how this dysfunction correlates with behavioral deficits. We predict that decreases in inter-hemispheric connectivity in motor and attention networks, which are bilaterally organized, will correlate with corresponding behavioral deficits and that these correlations will show functional specificity. For example, connectivity within an arm-defined motor network will predict upper-extremity function better than lower-extremity function. We determine the correlation between connectivity and behavior in an asymmetrically organized network, language, and compare the importance of inter-hemispheric vs intra-hemispheric connectivity. We examine how the functioning of multiple brain networks interact to produce a single behavioral deficit, and hypothesize that the connectivity of some networks, such as attention, correlates with behavior across domains. We measure fcMRl longtitudinally to determine if connectivity recovers in different networks at different rates and whether that recovery correlates with behavioral recovery. Finally, we study how changes in connectivity produced by a stroke depend on the type of tracts that are structurally damaged. PUBLIC HEALTH RELEVANCE: The goal of this proposal is to understand the effects of a stroke on the physiology of the brain and how they relate to the behavioral deficits produced by the stroke. We plan to measure these physiological effects in stroke patients using a novel method that will allow us to simultaneously assess the functioning of many different brain networks that are thought to underlie our ability to use language, attend in the environment, perform motor acts, and so forth. We will measure the ability of stroke patients to carry out these activities at different time points following their stroke, allowing us to understand how recovery of the patient's behavioral functions possibly relate to recovery of their physiological function.