Dan Xiaojuan, Hu Yang, Sun Junyan, Gao Linlin, Zhou Yongtao, Ma Jinghong, Doyon Julien, Wu Tao, Chan Piu
Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China.
Key Laboratory on Neurodegenerative Disorders of Ministry of Education, Key Laboratory on Parkinson's Disease of Beijing, Beijing, China.
Front Neurol. 2021 Aug 25;12:678013. doi: 10.3389/fneur.2021.678013. eCollection 2021.
Cognitive impairment is one of the most prominent non-motor symptoms in Parkinson's disease (PD), due in part to known cerebellar dysfunctions. Furthermore, previous studies have reported altered cerebellar functional connectivity (FC) in PD patients. Yet whether these changes are also due to the cognitive deficits in PD remain unclear. A total of 122 non-dementia participants, including 64 patients with early PD and 58 age- and gender-matched elderly controls were stratified into four groups based on their cognitive status (normal cognition vs. cognitive impairment). Cerebellar volumetry and FC were investigated by analyzing, respectively, structural and resting-state functional MRI data among groups using quality control and quantitative measures. Correlation analysis between MRI metrics and clinical features (motor and cognitive scores) were performed. Compared to healthy control subjects with no cognitive deficits, altered cerebellar FC were observed in early PD participants with both motor and cognitive deficits, but not in PD patients with normal cognition, nor elderly subjects showing signs of a cognitive impairment. Moreover, connectivity between the "motor" cerebellum and SMA was positively correlated with motor scores, while intracerebellar connectivity was positively correlated with cognitive scores in PD patients with cognitive impairment. No cerebellar volumetric difference was observed between groups. These findings show that altered cerebellar FC during resting state in early PD patients may be driven not solely by the motor deficits, but by cognitive deficits as well, hence highlighting the interplay between motor and cognitive functioning, and possibly reflecting compensatory mechanisms, in the early PD.
认知障碍是帕金森病（PD）最突出的非运动症状之一，部分原因是已知的小脑功能障碍。此外，先前的研究报道了PD患者小脑功能连接（FC）的改变。然而，这些变化是否也归因于PD的认知缺陷仍不清楚。共有122名非痴呆参与者，包括64名早期PD患者和58名年龄及性别匹配的老年对照者，根据他们的认知状态（正常认知与认知障碍）分为四组。通过使用质量控制和定量测量方法分别分析各组之间的结构和静息态功能MRI数据，研究小脑容积测量和FC。进行了MRI指标与临床特征（运动和认知评分）之间的相关性分析。与无认知缺陷的健康对照受试者相比，在有运动和认知缺陷的早期PD参与者中观察到小脑FC改变，但在认知正常的PD患者或有认知障碍迹象的老年受试者中未观察到。此外，在有认知障碍的PD患者中，“运动”小脑与辅助运动区之间的连接与运动评分呈正相关，而小脑内连接与认知评分呈正相关。各组之间未观察到小脑容积差异。这些发现表明，早期PD患者静息状态下小脑FC的改变可能不仅由运动缺陷驱动，还由认知缺陷驱动，从而突出了早期PD中运动和认知功能之间的相互作用，并可能反映了代偿机制。
