Department of Neurobiology, Key Laboratory on Neurodegenerative Disorders of Ministry of Education, Beijing Institute of Geriatrics, Xuanwu Hospital, Capital Medical University, Beijing, China.
Neuroimage. 2010 Feb 1;49(3):2581-7. doi: 10.1016/j.neuroimage.2009.10.051. Epub 2009 Oct 22.
Patients with Parkinson's disease (PD) have difficulty in performing learned movements automatically. The neural mechanism of this deficiency remains unclear. In the current study, we used functional MRI (fMRI) and psychophysiological interaction (PPI) methods to investigate the changes in effective connectivity of the brain networks when movements become automatic in PD patients and age-matched normal controls. We found that during automaticity, the rostral supplementary motor area, cerebellum, and cingulate motor area had increased effective connectivity with brain networks in PD patients. In controls, in addition to these regions, the putamen also had automaticity-related strengthened interactions with brain networks. The dorsal lateral prefrontal cortex had more connectivity at the novel stage than in the automatic stage in normal subjects, but not in PD patients. The comparison of the PPI results between the groups showed that the rostral supplementary motor area, cerebellum, and cingulate motor area had significantly more increased effective connectivity with several regions in normal subjects than in PD. The changes of effective connectivity in some areas negatively correlated with the Unified Parkinson's Disease Rating Scale (UPDRS). Our findings show that some of the factors related to PD patients having difficulty achieving automaticity are less efficient neural coding of movement and failure to shift execution of automatic movements more subcortically. The changes of effective connectivity become more abnormal as the disorder progresses. In addition, in PD, the connections of the attentional networks are altered.
帕金森病（PD）患者在自动执行习得运动方面存在困难。这种缺陷的神经机制尚不清楚。在目前的研究中，我们使用功能磁共振成像（fMRI）和心理生理交互（PPI）方法，研究了当运动在 PD 患者和年龄匹配的正常对照者中变得自动时大脑网络的有效连接变化。我们发现，在自动性过程中，额上辅助运动区、小脑和扣带回运动区与 PD 患者的大脑网络之间的有效连接增加。在对照组中，除了这些区域外，壳核也与大脑网络有自动相关的增强相互作用。在正常受试者中，背外侧前额叶皮层在新的阶段比在自动阶段有更多的连接，但在 PD 患者中则没有。对组间 PPI 结果的比较表明，额上辅助运动区、小脑和扣带回运动区与正常组中几个区域的有效连接显著增加。一些区域的有效连接变化与帕金森病统一评定量表（UPDRS）呈负相关。我们的研究结果表明，一些与 PD 患者难以实现自动性相关的因素是运动的神经编码效率较低，以及不能更皮质下地转移自动运动的执行。随着疾病的进展，有效连接的变化变得更加异常。此外，在 PD 中，注意力网络的连接发生改变。
