Neurophysiological Measurement in Aphasia Treatment

功能磁共振成像(FMRI)和弥散张量成像(DTI)均有助于表征失语症患者的神经生理状态。这种测量可用于开发治疗方法，选择针对患者的治疗方法，并衡量治疗的有效性。然而，失语症的脑成像必须得到改善。FMRI和DTI对头部运动和口咽运动都高度敏感，这些伪影在不流利的失语症患者中加剧，他们在发音方面更困难。中风通常是由血管系统的改变引起的和/或伴随着血管系统的改变，这可能会影响MRI信号。血流动力学的重新分布导致对MRI信号来源的模糊，该信号被认为是神经重组和/或重塑。再灌注出血产生的伪影导致病变附近的易感性伪影。拟议的工作将具体解决这些技术问题中的每一个，以促进失语症患者使用神经生理(功能成像)措施。 为了让功能磁共振成像和DTI指导治疗决策，必须有正式的方法来表征个体患者的生理状态，并将生物和行为参数关联起来。在该方案中，我们提出了两类度量：标量指数和网络激活图，并研究了它们与语音和语言度量的关系。标量指数将整个激活模式简化为单个数字，例如大脑偏侧化程度或胼胝体白质的完整性。网络地图包括 结构方程模型和欧几里德距离图，我们开发了方法来比较个人或群体(例如，接受和不接受治疗的患者)之间的这种大规模模型。这项研究旨在为失语症研究开发合理的神经生理学测量方法。 最后，这些方法的改进将应用于慢性非流利性失语和左额叶病变患者的治疗研究。治疗干预的基础是：(A)神经生物学观察到，大脑有通过观察-执行匹配而在运动模仿中特别活跃的回路，包括口头运动模仿；(B)行为学观察，模仿是许多非流利性失语症治疗的基石；以及(C)有利于强化方法和分级递增学习的治疗数据。通过生理和行为测量来评估结果，每三周收集一次，从治疗前六周开始，到治疗结束后六周结束。 治疗。

Both functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) can be helpful in characterizing the neurophysiological status of patients with aphasia. Such measurements can be used to develop treatment approaches, select patient-specific treatments, and gauge the effectiveness of treatment. However, brain imaging in aphasia must be improved. Both fMRI and DTI are highly sensitive to both head motion and oropharyngeal motion, and these artifacts are exacerbated in patients with non-fluent aphasia, who have a more difficult time producing speech. Stroke is often precipitated by and/or accompanied by alterations in vasculature, which can affect the MRI signal. Hemodynamic redistribution leads to ambiguity about the source of MRI signals presumed to indicate neural reorganization and/or remodeling. Artifacts from reperfusion hemorrhage leads to susceptibility artifact in the vicinity of lesions. The proposed work will specifically address each of these technical issues to facilitate the use of neurophysiological (functional imaging) measures in patients with aphasia. For fMRI and DTI to guide therapeutic decision-making, there must be formal ways to characterize the physiological state of individual patients and to correlate biological and behavioral parameters. In this proposal, we develop two classes of measures, scalar indices and network activation maps, and investigate their relationship to measures of speech and language. Scalar indices reduce an entire pattern of activation into a single number, such as degree of brain lateralization or integrity of callosal white matter. Network maps include structural equation models and Euclidean distance maps, and we develop methods to compare such large-scale models between individuals or groups (e.g., patients who do and do not benefit from therapy). This component of the research aims to develop rational neurophysiological measures for aphasia research. Finally, these methodological improvements will be applied to a treatment study for patients with chronic non-fluent aphasia and left frontal lesions. The therapeutic intervention is based on (a) neurobiological observations that the brain has circuits particularly active in motor imitation through observation-execution matching, including oral motor imitation; (b) behavioral observations that imitation is a cornerstone of many treatments for non-fluent aphasia; and (c) treatment data that favor intensive approaches and graded incremental learning. Outcomes are assessed by both physiological and behavioral measures, which are collected every three weeks starting six weeks before treatment and ending six weeks after completion of treatment.