Department of Radiology, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Department of Radiology, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China.
Department of Radiology, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
Neurosci Lett. 2019 Jul 13;705:159-166. doi: 10.1016/j.neulet.2019.04.042. Epub 2019 Apr 23.
Parkinson's disease (PD) is characterized with reduced dopamine level in the brain, resulting from the nigral degeneration. It is commonly accepted that the function of default mode network (DMN) is disturbed in PD, even in those who have no significant cognitive impairment. However, the relationship between the depletion of dopamine and DMN dysconnectivity is not fully clear. The aim of this study was to investigate the seed-based DMN connectivity and the influence of dopaminergic therapy on the DMN integrity in non-demented PD by using resting-state fMRI.
Resting-state fMRI data was collected from 24 non-demented PD patients before and after taking levodopa and 36 healthy controls (HCs). Functional connectivity (FC) was examined by a seed-based correlation approach.
Compared with HCs, decreased DMN connectivity in PD patients was observed, a number of which were significantly improved after taking levodopa therapy. Moreover, by directly comparing the DMN connectivity between ON- and OFF-medication conditions, we found significantly enhanced FC in a set of regions of DMN in the ON- medication condition. Conversely, we also found that the PCC revealed decreased FC with left inferior temporal.
DMN connectivity was found to be impaired in no-demented PD patients, and levodopa has the ability to impart a normalizing effect on DMN connectivity.
帕金森病（PD）的特征是大脑中的多巴胺水平降低，这是由于黑质变性所致。人们普遍认为，即使在没有明显认知障碍的 PD 患者中，默认模式网络（DMN）的功能也会受到干扰。然而，多巴胺耗竭与 DMN 连接中断之间的关系尚不完全清楚。本研究旨在通过静息态 fMRI 研究探讨非痴呆性 PD 患者的基于种子的 DMN 连接以及多巴胺能治疗对 DMN 完整性的影响。
收集 24 名未经治疗的 PD 患者在服用左旋多巴前后和 36 名健康对照者（HCs）的静息态 fMRI 数据。采用基于种子的相关方法来检查功能连接（FC）。
与 HCs 相比，PD 患者的 DMN 连接减少，其中一些在服用左旋多巴治疗后明显改善。此外，通过直接比较 ON 和 OFF 药物状态下的 DMN 连接，我们发现 ON 药物状态下 DMN 的一组区域的 FC 明显增强。相反，我们还发现 PCC 与左侧颞下回的 FC 降低。
在非痴呆性 PD 患者中发现 DMN 连接受损，左旋多巴具有对 DMN 连接产生正常化作用的能力。
