Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
Neurosci Lett. 2021 Aug 10;759:135970. doi: 10.1016/j.neulet.2021.135970. Epub 2021 May 21.
Freezing of gait (FOG) is a common and debilitating gait disturbance in patients with Parkinson's disease (PD), but the potential mechanisms are still unclear. This study aimed to explore alterations in the topological organization of whole-brain functional networks in PD patients with FOG.
We recruited 75 patients with PD, 37 patients with FOG and 38 patients without FOG, to undergo resting-state functional magnetic resonance imaging (fMRI). The whole-brain functional networks were constructed, and the topological properties at three (global, nodal, and connectional) levels were analyzed using graph theory approaches.
Compared with patients without FOG, patients with FOG exhibited altered global topological properties (a significant decrease in the normalized clustering coefficient and small-worldness), implying a shift toward randomization in their functional brain networks. At the node and connectional levels, patients with FOG showed increased nodal centralities and functional connectivity in the sensorimotor network, frontoparietal network, visual network, subcortical and limbic regions, and decreased nodal centralities in the frontoparietal network and the cerebellum. Furthermore, the altered nodal centralities in the right hippocampus (HIP) were positively correlated with FOG severity.
This study suggests that FOG in PD is associated with disrupted topological organization of whole-brain functional networks, involving dysfunction of the multiple networks.
冻结步态（FOG）是帕金森病（PD）患者常见且使人虚弱的步态障碍，但潜在机制仍不清楚。本研究旨在探索伴有 FOG 的 PD 患者全脑功能网络拓扑组织的改变。
我们招募了 75 名 PD 患者、37 名伴有 FOG 的患者和 38 名不伴有 FOG 的患者进行静息态功能磁共振成像（fMRI）检查。使用图论方法构建全脑功能网络，并分析三个（全局、节点和连接）水平的拓扑性质。
与不伴有 FOG 的患者相比，伴有 FOG 的患者表现出全局拓扑性质的改变（标准化聚类系数和小世界指数显著降低），提示其功能脑网络向随机化转变。在节点和连接水平上，伴有 FOG 的患者表现出感觉运动网络、额顶叶网络、视觉网络、皮质下和边缘区域的节点中心性增加，额顶叶网络和小脑的节点中心性降低。此外，右侧海马体（HIP）的改变节点中心性与 FOG 严重程度呈正相关。
本研究表明，PD 中的 FOG 与全脑功能网络拓扑组织的破坏有关，涉及多个网络的功能障碍。
