Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China.
Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China.
Neurobiol Dis. 2023 Sep;185:106265. doi: 10.1016/j.nbd.2023.106265. Epub 2023 Aug 18.
Freezing of gait (FOG) is an intractable and paroxysmal gait disorder that seriously affects the quality of life of Parkinson's disease (PD) patients. Emerging studies have reported abnormal brain activity of distributed networks in FOG patients, whereas ignoring the intrinsic dynamic fluctuations of functional connectivity. The purpose of this study was to examine the dynamic functional network connectivity (dFNC) of PD-FOG.
In total, 52 PD patients with FOG (PD-FOG), 73 without FOG (PD-NFOG) and 38 healthy controls (HCs) received resting state functional magnetic resonance imaging (rs-fMRI). Sliding window method, k-means clustering and graph theory analysis were employed to retrieve dynamic characteristics of PD-FOG. Partial correlation analysis was conducted to verify whether the dFNC was related to freezing gait severity.
Seven brain networks were identified and configured into seven states. Compared to PD-NFOG, significant spatial pattern was identified for state 2 in freezers, showing increased functional coupling between default mode network (DMN) and basal ganglia network (BG), as a concrete manifestation of increased precuneus-caudate coupling. The mean dwell time and fractional window of state 2 had a positive correlation with FOG severity. Furthermore, PD-FOG group exhibited lower variance in nodal efficiency of independent components (IC) 7 (left precuneus).
Our study suggested that aberrant coupling of precuneus-caudate and disrupted variability of precuneus efficiency might be associated to the neural mechanisms of FOG.
冻结步态（FOG）是一种难以治疗且阵发性的步态障碍，严重影响帕金森病（PD）患者的生活质量。新兴研究报告称，FOG 患者的分布式网络存在异常脑活动，而忽略了功能连接的固有动态波动。本研究旨在探讨 PD-FOG 的动态功能网络连接（dFNC）。
共纳入 52 例有 FOG（PD-FOG）、73 例无 FOG（PD-NFOG）的 PD 患者和 38 名健康对照者（HCs）进行静息态功能磁共振成像（rs-fMRI）检查。采用滑动窗口法、k-均值聚类和图论分析提取 PD-FOG 的动态特征。进行偏相关分析以验证 dFNC 是否与冻结步态严重程度相关。
共识别出 7 个脑网络，并将其配置为 7 个状态。与 PD-NFOG 相比，FOG 者在冻结状态 2 中出现了明显的空间模式，表现为默认模式网络（DMN）和基底节网络（BG）之间的功能连接增强，具体表现为楔前叶-尾状核连接增强。状态 2 的平均停留时间和分数窗口与 FOG 严重程度呈正相关。此外，PD-FOG 组独立成分（IC）7（左侧楔前叶）的节点效率变异性较低。
本研究表明，楔前叶-尾状核的异常连接和楔前叶效率变异性的破坏可能与 FOG 的神经机制有关。
