Müller-Oehring Eva M, Sullivan Edith V, Pfefferbaum Adolf, Huang Neng C, Poston Kathleen L, Bronte-Stewart Helen M, Schulte Tilman
Department of Psychiatry & Behavioral Sciences, Stanford University School of Medicine, 401 Quarry Road, Stanford, CA, 94305-5723, USA.
Neuroscience Program, SRI International, Menlo Park, CA, 94025, USA.
Brain Imaging Behav. 2015 Sep;9(3):619-38. doi: 10.1007/s11682-014-9317-9.
Parkinson's disease (PD) is associated with abnormal synchronization in basal ganglia-thalamo-cortical loops. We tested whether early PD patients without demonstrable cognitive impairment exhibit abnormal modulation of functional connectivity at rest, while engaged in a task, or both. PD and healthy controls underwent two functional MRI scans: a resting-state scan and a Stroop Match-to-Sample task scan. Rest-task modulation of basal ganglia (BG) connectivity was tested using seed-to-voxel connectivity analysis with task and rest time series as conditions. Despite substantial overlap of BG-cortical connectivity patterns in both groups, connectivity differences between groups had clinical and behavioral correlates. During rest, stronger putamen-medial parietal and pallidum-occipital connectivity in PD than controls was associated with worse task performance and more severe PD symptoms suggesting that abnormalities in resting-state connectivity denote neural network dedifferentiation. During the executive task, PD patients showed weaker BG-cortical connectivity than controls, i.e., between caudate-supramarginal gyrus and pallidum-inferior prefrontal regions, that was related to more severe PD symptoms and worse task performance. Yet, task processing also evoked stronger striatal-cortical connectivity, specifically between caudate-prefrontal, caudate-precuneus, and putamen-motor/premotor regions in PD relative to controls, which was related to less severe PD symptoms and better performance on the Stroop task. Thus, stronger task-evoked striatal connectivity in PD demonstrated compensatory neural network enhancement to meet task demands and improve performance levels. fMRI-based network analysis revealed that despite resting-state BG network compromise in PD, BG connectivity to prefrontal, premotor, and precuneus regions can be adequately invoked during executive control demands enabling near normal task performance.
帕金森病（PD）与基底神经节 - 丘脑 - 皮质环路的异常同步有关。我们测试了无明显认知障碍的早期PD患者在静息状态、执行任务时或两者兼有的情况下是否表现出功能连接的异常调制。PD患者和健康对照者接受了两次功能磁共振成像扫描：一次静息状态扫描和一次Stroop样本匹配任务扫描。使用种子点到体素的连接性分析，以任务和静息时间序列为条件，测试基底神经节（BG）连接性的静息 - 任务调制。尽管两组的BG - 皮质连接模式有大量重叠，但组间连接性差异与临床和行为相关。在静息状态下，PD患者与对照组相比，壳核 - 内侧顶叶和苍白球 - 枕叶的连接性更强，这与任务表现较差和PD症状更严重有关，表明静息状态连接性异常意味着神经网络去分化。在执行任务期间，PD患者表现出比对照组更弱的BG - 皮质连接性，即尾状核 - 缘上回和苍白球 - 前额叶下部区域之间，这与更严重的PD症状和更差的任务表现有关。然而，任务处理也在PD患者中诱发了更强的纹状体 - 皮质连接性，特别是相对于对照组，尾状核 - 前额叶、尾状核 - 楔前叶和壳核 - 运动/运动前区之间，这与较轻的PD症状和在Stroop任务上更好的表现有关。因此，PD患者中更强的任务诱发纹状体连接性表明神经网络的代偿性增强，以满足任务需求并提高表现水平。基于功能磁共振成像的网络分析表明，尽管PD患者静息状态下BG网络受损，但在执行控制需求期间，BG与前额叶、运动前区和楔前叶区域的连接性可以被充分激活，从而实现接近正常的任务表现。
