Department of Neurology, Washington University School of Medicine, 4525 Scott Avenue, St. Louis, MO 63110, USA.
Ann Neurol. 2010 Mar;67(3):365-75. doi: 10.1002/ana.21905.
Focal brain lesions can have important remote effects on the function of distant brain regions. The resulting network dysfunction may contribute significantly to behavioral deficits observed after stroke. This study investigates the behavioral significance of changes in the coherence of spontaneous activity in distributed networks after stroke by measuring resting state functional connectivity (FC) using functional magnetic resonance imaging.
In acute stroke patients, we measured FC in a dorsal attention network and an arm somatomotor network, and determined the correlation of FC with performance obtained in a separate session on tests of attention and motor function. In particular, we compared the behavioral correlation with intrahemispheric FC to the behavioral correlation with interhemispheric FC.
In the attention network, disruption of interhemispheric FC was significantly correlated with abnormal detection of visual stimuli (Pearson r with field effect = -0.624, p = 0.002). In the somatomotor network, disruption of interhemispheric FC was significantly correlated with upper extremity impairment (Pearson r with contralesional Action Research Arm Test = 0.527, p = 0.036). In contrast, intrahemispheric FC within the normal or damaged hemispheres was not correlated with performance in either network. Quantitative lesion analysis demonstrated that our results could not be explained by structural damage alone.
These results suggest that lesions cause state changes in the spontaneous functional architecture of the brain, and constrain behavioral output. Clinically, these results validate using FC for assessing the health of brain networks, with implications for prognosis and recovery from stroke, and underscore the importance of interhemispheric interactions.
大脑局灶性病变可能对远距离脑区的功能产生重要的远程影响。由此产生的网络功能障碍可能是中风后观察到的行为缺陷的重要原因。本研究通过使用功能磁共振成像测量静息状态功能连接（FC），研究中风后分布式网络中自发性活动相干性变化对行为的意义。
在急性中风患者中，我们测量了背侧注意网络和手臂躯体运动网络的 FC，并确定了 FC 与注意力和运动功能测试中单独获得的表现之间的相关性。特别是，我们将 FC 与半球内 FC 的行为相关性与 FC 与半球间 FC 的行为相关性进行了比较。
在注意网络中，半球间 FC 的破坏与视觉刺激的异常检测显著相关（与场效应的 Pearson r = -0.624，p = 0.002）。在躯体运动网络中，半球间 FC 的破坏与上肢功能障碍显著相关（与对侧 Action Research Arm Test 的 Pearson r = 0.527，p = 0.036）。相比之下，正常或受损半球内的半球内 FC 与两个网络中的表现均无相关性。定量病变分析表明，我们的结果不能仅用结构损伤来解释。
这些结果表明，病变导致大脑自发性功能结构的状态变化，并限制了行为输出。从临床角度来看，这些结果验证了使用 FC 评估大脑网络健康状况的有效性，这对中风的预后和恢复具有重要意义，并强调了半球间相互作用的重要性。
