Neurodegenerative Diseases Center, Department of Medicine and Surgery, University of Salerno, Via Allende, 84081, Baronissi, SA, Italy.
J Neurol. 2015 Feb;262(2):425-34. doi: 10.1007/s00415-014-7591-5. Epub 2014 Nov 27.
Cognitive impairment is common in PD, even in early stages. The construct of mild cognitive impairment has been used to identify clinically evident cognitive impairment without functional decline in PD patients (PD-MCI). The aim of the present study was to investigate brain connectivity associated with PD-MCI through RS-fMRI. RS-fMRI at 3T was collected in 42 PD patients and 20 matched healthy controls. Among PD patients, 21 were classified as having MCI (PD-MCI) and 21 as cognitively unimpaired (PD-nMCI) based on criteria for possible PD-MCI (level I category). Single-subject and group-level ICA was used to investigate the integrity of brain networks related to cognition in PD patients with and without MCI. Image data processing and statistical analysis were performed in BrainVoyager QX. In addition, we used VBM to test whether functional connectivity differences were related to structural abnormalities. PD-nMCI and PD-MCI patients compared with controls showed decreased DMN connectivity. PD-MCI patients, but not PD-nMCI, compared with controls, showed decreased functional connectivity of bilateral prefrontal cortex within the frontoparietal network. The decreased prefrontal cortex connectivity correlated with cognitive parameters but not with clinical variables. VBM analysis did not reveal any difference in local gray matter between patients and controls. Our findings suggest that an altered DMN connectivity characterizes PD patients, regardless of cognitive status, whereas a functional disconnection of the frontoparietal network could be associated with MCI in PD in the absence of detectable structural changes.
认知障碍在 PD 中很常见，即使在早期阶段也是如此。轻度认知障碍的构建已被用于识别 PD 患者中明显的认知障碍而无功能下降（PD-MCI）。本研究旨在通过 RS-fMRI 研究与 PD-MCI 相关的大脑连接。在 3T 下收集了 42 名 PD 患者和 20 名匹配的健康对照者的 RS-fMRI 数据。在 PD 患者中，根据可能的 PD-MCI（I 类）标准，21 名患者被分类为有 MCI（PD-MCI），21 名患者为认知未受损（PD-nMCI）。使用单个体和组水平的 ICA 研究了 MCI 和无 MCI 的 PD 患者相关认知的大脑网络的完整性。在 BrainVoyager QX 中进行图像数据处理和统计分析。此外，我们还使用 VBM 测试功能连接差异是否与结构异常有关。与对照组相比，PD-nMCI 和 PD-MCI 患者的 DMN 连接减少。与对照组相比，PD-MCI 患者而非 PD-nMCI 患者的额顶叶网络双侧前额叶皮层的功能连接减少。前额叶皮层连接的减少与认知参数相关，但与临床变量无关。VBM 分析未显示患者和对照组之间局部灰质有任何差异。我们的研究结果表明，DMN 连接的改变特征是 PD 患者，无论认知状态如何，而额顶叶网络的功能分离可能与 PD 中的 MCI 有关，而没有可检测到的结构变化。
