James G Andrew, Lu Zhong-Lin, VanMeter John W, Sathian K, Hu Xiaoping P, Butler Andrew J
Wallace H. Coulter Department of Biomedical Engineering, Emory University and the Georgia Institute of Technology, Atlanta, USA.
Top Stroke Rehabil. 2009 Jul-Aug;16(4):270-81. doi: 10.1310/tsr1604-270.
A promising paradigm in human neuroimaging is the study of slow (<0.1 Hz) spontaneous fluctuations in the hemodynamic response measured by functional magnetic resonance imaging (fMRI). Spontaneous activity (i.e., resting state) refers to activity that cannot be attributed to specific inputs or outputs, that is, activity intrinsically generated by the brain.
This article presents pilot data examining neural connectivity in patients with poststroke hemiparesis before and after 3 weeks of upper extremity rehabilitation in the Accelerated Skill Acquisition Program (ASAP). Resting-state fMRI data acquired pre and post therapy were analyzed using an exploratory adaptation of structural equation modeling (SEM) to evaluate therapy-related changes in motor network effective connectivity.
Each ASAP patient showed behavioral improvement. ASAP patients also showed increased influence of the affected hemisphere premotor cortex (a-PM) upon the unaffected hemisphere premotor cortex (u-PM) following therapy. The influence of a-PM on affected hemisphere primary motor cortex (a-M1) also increased with therapy for 3 of 5 patients, including those with greatest behavioral improvement.
Our findings suggest that network analyses of resting-state fMRI constitute promising tools for functional characterization of functional brain disorders, for intergroup comparisons, and potentially for assessing effective connectivity within single subjects; all of which have important implications for stroke rehabilitation.
人类神经影像学中一个有前景的范例是对通过功能磁共振成像（fMRI）测量的血液动力学反应中的缓慢（<0.1 Hz）自发波动进行研究。自发活动（即静息状态）是指不能归因于特定输入或输出的活动，也就是说，是大脑内在产生的活动。
本文展示了在加速技能习得计划（ASAP）中，对中风后偏瘫患者在进行3周上肢康复前后的神经连接性进行检测的初步数据。使用结构方程模型（SEM）的探索性改编方法分析治疗前后采集的静息态fMRI数据，以评估运动网络有效连接性中与治疗相关的变化。
每位ASAP患者均表现出行为改善。ASAP患者在治疗后还表现出患侧半球运动前区皮层（a-PM）对健侧半球运动前区皮层（u-PM）的影响增加。对于5名患者中的3名，包括行为改善最大的患者，a-PM对患侧半球初级运动皮层（a-M1）的影响也随着治疗而增加。
我们的研究结果表明，静息态fMRI的网络分析是用于功能性脑疾病功能特征描述、组间比较以及潜在地评估单一个体内有效连接性的有前景的工具；所有这些对中风康复都具有重要意义。
