Laboratory of Early Markers of Neurodegeneration (LEMON), Center for the Study of Movement, Cognition, and Mobility, Neurological Institute, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; Department of Neurology, Sackler School of Medicine, Tel Aviv University, Israel; Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.
Laboratory of Early Markers of Neurodegeneration (LEMON), Center for the Study of Movement, Cognition, and Mobility, Neurological Institute, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Israel.
J Neurol Sci. 2022 Nov 15;442:120452. doi: 10.1016/j.jns.2022.120452. Epub 2022 Oct 10.
The mechanisms underlying cognitive disturbances in Parkinson's disease (PD) are poorly understood but likely to depend on the ongoing degenerative processes affecting structural and functional connectivity (FC). This pilot study examined patterns of FC alterations during a cognitive task using EEG and structural characteristics of white matter (WM) pathways connecting these activated regions in early-stage PD. Eleven PD patients and nine healthy controls (HCs) underwent EEG recording during an auditory oddball task and MRI scans. Source localization was performed and Gaussian mixture model was fitted to identify brain regions with high power during task performance. These areas served as seed regions for connectivity analysis. FC among these regions was assessed by measures of magnitude squared coherence (MSC), and phase-locking value (PLV), while structural connectivity was evaluated using fiber tracking based on diffusion tensor imaging (DTI). The paracentral lobule (PL), superior parietal lobule (SPL), superior and middle frontal gyrus (SMFG), parahippocampal gyrus, superior and middle temporal gyri (STG, MTG) demonstrated increased activation during task performance. Compared to HCs, PD showed lower FC between SMFG and PL and between SMFG and SPL in MSC (p = 0.012 and p = 0.036 respectively). No significant differences between the groups were observed in PLV and the measured DTI metrics along WM tracts. These findings demonstrate that in early PD, cognitive performance changes might be attributed to FC alterations, suggesting that FC is affected early on in the degenerative process, whereas structural damage is more prominent in advanced stages as a result of the disease burden accumulation.
帕金森病（PD）认知障碍的潜在机制尚不清楚，但可能依赖于影响结构和功能连接（FC）的持续退化过程。这项初步研究使用 EEG 检查了早期 PD 患者在认知任务期间 FC 改变的模式，以及连接这些激活区域的白质（WM）通路的结构特征。11 名 PD 患者和 9 名健康对照（HC）在进行听觉Oddball 任务期间接受了 EEG 记录和 MRI 扫描。进行了源定位，并对高斯混合模型进行拟合，以识别在任务执行过程中具有高功率的脑区。这些区域作为连接分析的种子区域。通过幅度平方相干（MSC）和锁相值（PLV）评估这些区域之间的 FC，而使用基于扩散张量成像（DTI）的纤维跟踪评估结构连接。在任务执行过程中，中央旁小叶（PL）、顶上小叶（SPL）、额上回和额中回（SMFG）、海马旁回、颞上回和中回（STG、MTG）表现出更高的激活。与 HCs 相比，PD 在 MSC 中 SMFG 和 PL 之间以及 SMFG 和 SPL 之间的 FC 较低（p=0.012 和 p=0.036）。在 PLV 和 WM 束沿路上测量的 DTI 指标方面，两组之间没有观察到显著差异。这些发现表明，在早期 PD 中，认知表现的变化可能归因于 FC 的改变，这表明 FC 在退化过程的早期阶段就受到影响，而结构损伤在疾病负担积累的晚期更为明显。
