Department of Neurology, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA.
Neuroscience. 2010 Mar 17;166(2):712-9. doi: 10.1016/j.neuroscience.2009.12.036. Epub 2009 Dec 24.
Both the basal ganglia and cerebellum are known to influence cortical motor and motor-associated areas via the thalamus. Whereas striato-thalamo-cortical (STC) motor circuit dysfunction has been implicated clearly in Parkinson's disease (PD), the role of the cerebello-thalamo-cortical (CTC) motor circuit has not been well defined. Functional magnetic resonance imaging (fMRI) is a convenient tool for studying the role of the CTC in vivo in PD patients, but large inter-individual differences in fMRI activation patterns require very large numbers of subjects in order to interpret data from cross-sectional, case control studies. To understand the role of the CTC during PD progression, we obtained longitudinal fMRI 2 years apart from 5 PD (57+/-8 yr) and five Controls (57+/-9 yr) performing either externally- (EG) or internally-guided (IG) sequential finger movements. All PD subjects had unilateral motor symptoms at baseline, but developed bilateral symptoms at follow-up. Within-group analyses were performed by comparing fMRI activation patterns between baseline and follow-up scans. Between-group comparisons were made by contrasting fMRI activation patterns generated by the more-affected and less-affected hands of PD subjects with the mean of the dominant and non-dominant hands of Controls. Compared to baseline, Controls showed changes in CTC circuits, but PD subjects had increased recruitment of both cortical motor-associated and cerebellar areas. Compared to Controls, PD subjects demonstrated augmented recruitment of CTC circuits over time that was statistically significant when the IG task was performed by the hand that transitioned from non-symptomatic to symptomatic. This longitudinal fMRI study demonstrates increased recruitment of the CTC motor circuit concomitant with PD progression, suggesting a role of the CTC circuit in accommodation to, or pathophysiology of, PD.
基底神经节和小脑都被认为通过丘脑影响皮质运动和与运动相关的区域。虽然纹状体-丘脑-皮质(STC)运动回路功能障碍已明确与帕金森病(PD)有关,但小脑-丘脑-皮质(CTC)运动回路的作用尚未得到很好的定义。功能磁共振成像(fMRI)是研究 PD 患者体内 CTC 作用的便捷工具,但 fMRI 激活模式的个体间差异很大,需要非常多的受试者才能解释横断面、病例对照研究的数据。为了了解 CTC 在 PD 进展过程中的作用,我们对 5 名 PD(57+/-8 岁)和 5 名对照者(57+/-9 岁)进行了为期 2 年的纵向 fMRI 检查,这些人分别进行外部(EG)或内部(IG)引导的手指序列运动。所有 PD 患者在基线时均有单侧运动症状,但在随访时发展为双侧症状。通过比较基线和随访扫描的 fMRI 激活模式进行组内分析。通过对比 PD 患者受影响更严重和较不严重的手与对照者的优势手和非优势手的平均 fMRI 激活模式进行组间比较。与基线相比,对照组显示 CTC 回路发生变化,但 PD 患者皮质运动相关区域和小脑区域的募集增加。与对照组相比,PD 患者的 CTC 回路随时间推移的募集增加,当 IG 任务由从不症状手向症状手过渡的手执行时,这一增加具有统计学意义。这项纵向 fMRI 研究表明,随着 PD 的进展,CTC 运动回路的募集增加,提示 CTC 回路在适应或 PD 的病理生理学中起作用。