Joint amplitude and connectivity compensatory mechanisms in Parkinson's disease

Palmer, Samantha; Li, J.; Wang, Z.J.; McKeown, Martin J.

doi:10.1016/j.neuroscience.2010.01.012

Cited by 83 publications

(61 citation statements)

References 39 publications

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“…They also reported that EC between M1 and the pre-SMA, premotor cortex, parietal cortex, and cerebellum was increased relative to controls, and positively related to UPDRS (Wu et al, 2011b). The increases in cortical-cortical EC are proposed to be compensatory mechanisms for the decreases in subcortical-cortical EC (Palmer et al, 2010;Wu et al, 2011b). These findings are consistent with our observation of a tendency for increases in subcortical-cortical task-related FC in patients who pedal faster.…”

Section: Discussionsupporting

confidence: 90%

“…Such task-related FC is not as commonly studied as resting-state FC, though several groups have published measures of effective connectivity (EC) during a task (Helmich et al, 2009;Palmer et al, 2009Palmer et al, , 2010Wu et al, 2010Wu et al, , 2011b. EC differs from FC in that it is measured during a traditional fMRI scan (i.e., with alternating task blocks), rather than in what we refer to as an fcMRI scan, in which the subject is in a constant state throughout the entire scan.…”

Section: Discussionmentioning

confidence: 99%

“…Further, EC measures the degree to which the activity of one region contributes to another (Wu et al, 2011b). A study of particular interest is that by Palmer et al (2010) as the force tracking device and task used was similar to that of this study, though it was applied in a block design. They reported that EC during the task in PD patients was decreased in the striato-thalamo-cortical pathway, and increased in the cerebello-thalamo-cortical pathway, relative to normal controls (Palmer et al, 2010).…”

Section: Discussionmentioning

confidence: 99%

“…A study of particular interest is that by Palmer et al (2010) as the force tracking device and task used was similar to that of this study, though it was applied in a block design. They reported that EC during the task in PD patients was decreased in the striato-thalamo-cortical pathway, and increased in the cerebello-thalamo-cortical pathway, relative to normal controls (Palmer et al, 2010). Wu and associates (2011b) reported similar findings of EC during a selfinitiated finger tapping task.…”

Section: Discussionmentioning

confidence: 99%

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Exercise Therapy for Parkinson's Disease: Pedaling Rate Is Related to Changes in Motor Connectivity

et al. 2016

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Forced-rate lower-extremity exercise has recently emerged as a potential safe and low-cost therapy for Parkinson's disease (PD). The efficacy is believed to be dependent on pedaling rate, with rates above the subjects' voluntary exercise rates being most beneficial. In this study, we use functional connectivity magnetic resonance imaging (MRI) to further elucidate the mechanism underlying this effect. Twenty-seven PD patients were randomized to complete 8 weeks of forced-rate exercise (FE) or voluntary-rate exercise (VE). Exercise was delivered using a specialized stationary bicycle, which can augment patients' voluntary exercise rates. The FE group received assistance from the cycle. Imaging was conducted at baseline, end of therapy, and after 4 weeks of follow-up. Functional connectivity (FC) was determined via seed-based correlation analysis, using activationbased seeds in the primary motor cortex (M1). The change in FC after exercise was compared using linear correlation with pedaling rate. Results of the correlation analysis showed a strong positive correlation between pedaling rate and change in FC from the most affected M1 to the ipsilateral thalamus. This effect persisted after 4 weeks of follow-up. These results indicate that a plausible mechanism for the therapeutic efficacy of high-rate exercise in PD is that it improves thalamo-cortical connectivity.

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Section: Discussionsupporting

confidence: 90%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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Exercise Therapy for Parkinson's Disease: Pedaling Rate Is Related to Changes in Motor Connectivity

et al. 2016

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“…Another group used this technique to show reduced connectivity between inferior parietal cortex and the posterior putamen, while coupling of this region to the anterior putamen was increased [9]. Yet other investigators have shown that areas active during rest ("default mode network") demonstrate increased activity but reduced connectivity in PD [10].…”

Section: Magnetic Resonance Imagingmentioning

confidence: 99%

Neuroimaging in Parkinson's Disease

Stoessl

2011

Neurotherapeutics

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Structural covariance networks of striatum subdivision in patients with Parkinson's disease

Chou¹,

Lin

Lee

et al. 2014

Human Brain Mapping

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Parkinson's disease (PD) is a neurodegenerative disorder associated with the striatum. Previous studies indicated that subdivisions of the striatum with distinct functional connectivity profiles contribute to different pathogeneses in PD. Segregated structural covariance (SC) pattern between the striatum and neocortex observed in healthy subjects, however, remain unknown in PD. The purpose of this study is to map and compare the subregional striatal SC network organization between 30 healthy controls and 48 PD patients and to investigate their association with the disease severity. The striatal SC network was statistically inferred by correlating the mean gray matter (GM) volume of six striatal subdivisions (including the bilateral dorsal caudate, superior ventral striatum, inferior ventral striatum, dorsal caudal putamen, dorsal rostral putamen, and ventral rostral putamen) with the entire neocortical GM volume in voxel-wise manner. The PD patients revealed marked atrophy in the striatum, cerebellum, and extra-striatum neocortices. As predicted, segregated striatal SC network patterns were observed in both groups. This suggests that in PD, pathological processes occurring in the striatum affect the same striato-cortical networks that covary with the striatum in healthy brains. The PD patients further demonstrated atypical striatal SC patterns between the caudate, parahippocampus temporal cortices, and cerebellum, which corresponded to dopaminergic associated network. The areas with significant group differences in SC were further associated with disease severity. Our findings support previous studies indicating that PD is associated with altered striato-cortical networks, and suggest that structural changes in the striatum may result in a cascade of alterations in multiple neocortices.

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Joint amplitude and connectivity compensatory mechanisms in Parkinson's disease

Cited by 83 publications

References 39 publications

Exercise Therapy for Parkinson's Disease: Pedaling Rate Is Related to Changes in Motor Connectivity

Exercise Therapy for Parkinson's Disease: Pedaling Rate Is Related to Changes in Motor Connectivity

Neuroimaging in Parkinson's Disease

Structural covariance networks of striatum subdivision in patients with Parkinson's disease

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