Background: 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. Methods: 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. Results: 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. Conclusions: 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.

中文翻译：

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患有认知障碍的早期帕金森病患者小脑静息态功能连接的改变。


背景：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，之前的研究报道了帕金森病患者小脑功能连接（FC）的改变。然而，这些变化是否也是帕金森病认知缺陷所致仍不清楚。方法：共有 122 名非痴呆参与者，包括 64 名早期 PD 患者和 58 名年龄和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分别分析各组的结构和静息态功能 MRI 数据，对小脑容量和 FC 进行了研究。对 MRI 指标和临床特征（运动和认知评分）之间进行相关性分析。结果：与没有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 患者中观察到小脑 FC 改变，也没有在表现出认知障碍迹象的老年受试者中观察到改变。此外，“运动”小脑和 SMA 之间的连接与运动评分呈正相关，而小脑内连接与认知障碍 PD 患者的认知评分呈正相关。组间未观察到小脑体积差异。结论：这些研究结果表明，早期 PD 患者静息状态下小脑 FC 的改变可能不仅是由运动缺陷驱动的，还可能是由认知缺陷驱动的，因此强调了运动功能和认知功能之间的相互作用，并可能反映了补偿机制。早期的PD。