Cheng Yilin, Yang Huaguang, Liu Weiyin Vivian, Wen Zhi, Chen Jun
Department of Radiology, Renmin Hospital of Wuhan University, Wuhan, China.
MR Research, GE Healthcare, Beijing, China.
Front Neurosci. 2022 Aug 16;16:954332. doi: 10.3389/fnins.2022.954332. eCollection 2022.
Freezing of gait (FOG) in multiple system atrophy (MSA) is characterized by a higher risk of falls and a reduced quality of life; however, the mechanisms underlying these effects have yet to be identified by neuroimaging. The aim of this study was to investigate the differences in functional network when compared between MSA patients with and without freezing.
Degree centrality (DC) based on the resting-state functional magnetic resonance imaging was computed in 65 patients with MSA and 36 healthy controls. Brain regions with statistically different DC values between groups were selected as seed points for a second seed-based functional connectivity (FC) analysis. The relationships between brain activity (DC and FC alterations) and the severity of freezing symptoms were then investigated in the two groups of patients with MSA.
Compared to MSA patients without FOG symptoms (MSA-nFOG), patients with MSA-FOG showed an increased DC in the left middle temporal gyrus but a reduced DC in the right superior pole temporal gyrus, left anterior cingulum cortex, left thalamus, and right middle frontal gyrus. Furthermore, in patients with MSA-FOG, the DC in the left thalamus was negatively correlated with FOG scores. Using the left thalamus as a seed, secondary seed-based functional connectivity analysis revealed that patients with MSA-FOG commonly showed the left thalamus-based FC abnormalities in regions related to cognition and emotion. In contrast to the patients with MSA-nFOG, patients with MSA-FOG showed an increased FC between the left thalamus and the left middle temporal gyrus (MTG), right inferior parietal lobule (IPL), bilateral cerebellum_8, and left precuneus.
Freezing of gait is associated with centrality of the impaired thalamus network. Abnormal FC between the thalamus and left MTG, right IPL, bilateral cerebellum_8, and left precuneus was involved in FOG. These results provide new insight into the pathophysiological mechanism of FOG in MSA.
多系统萎缩（MSA）中的冻结步态（FOG）的特征是跌倒风险较高且生活质量下降；然而，这些影响背后的机制尚未通过神经影像学确定。本研究的目的是调查有冻结和无冻结的MSA患者之间功能网络的差异。
基于静息态功能磁共振成像计算65例MSA患者和36名健康对照者的度中心性（DC）。选择两组之间DC值有统计学差异的脑区作为种子点进行第二次基于种子的功能连接（FC）分析。然后在两组MSA患者中研究脑活动（DC和FC改变）与冻结症状严重程度之间的关系。
与无FOG症状的MSA患者（MSA-nFOG）相比，MSA-FOG患者左侧颞中回的DC增加，但右侧颞上极、左侧前扣带回皮质、左侧丘脑和右侧额中回的DC降低。此外，在MSA-FOG患者中，左侧丘脑的DC与FOG评分呈负相关。以左侧丘脑为种子，基于种子的二级功能连接分析显示，MSA-FOG患者在与认知和情感相关的区域通常表现出基于左侧丘脑的FC异常。与MSA-nFOG患者相比，MSA-FOG患者左侧丘脑与左侧颞中回（MTG）、右侧顶下小叶（IPL）、双侧小脑_8和左侧楔前叶之间的FC增加。
冻结步态与受损丘脑网络的中心性有关。丘脑与左侧MTG、右侧IPL、双侧小脑_8和左侧楔前叶之间的异常FC与FOG有关。这些结果为MSA中FOG的病理生理机制提供了新的见解。
