Functional connectivity of cortical motor areas in the resting state in Parkinson's disease

Abstract

Parkinson's disease (PD) patients have difficulty in initiating movements. Previous studies have suggested that the abnormal brain activity may happen not only during performance of self-initiated movements but also in the before movement (baseline or resting) state. In the current study, we investigated the functional connectivity of brain networks in the resting state in PD. We chose the rostral supplementary motor area (pre-SMA) and bilateral primary motor cortex (M1) as "seed" regions, because the pre-SMA is important in motor preparation, whereas the M1 is critical in motor execution. FMRIs were acquired in 18 patients and 18 matched controls. We found that in the resting state, the pattern of connectivity with both the pre-SMA or the M1 was changed in PD. Connectivity with the pre-SMA in patients with PD compared to normal subjects was increased connectivity to the right M1 and decreased to the left putamen, right insula, right premotor cortex, and left inferior parietal lobule. We only found stronger connectivity in the M1 with its own local region in patients with PD compared to controls. Our findings demonstrate that the interactions of brain networks are abnormal in PD in the resting state. There are more connectivity changes of networks related to motor preparation and initiation than to networks of motor execution in PD. We postulate that these disrupted connections indicate a lack of readiness for movement and may be partly responsible for difficulty in initiating movements in PD.

Deep Brain Stimulation of the Subthalamic Nucleus, but not Dopaminergic Medication, Improves Proactive Inhibitory Control of Movement Initiation in Parkinson's Disease

“…For instance, impaired activation of the medial frontal areas and putamen accounts for the difficulties PD patients have in initiating movements [69], with concomitant over-activity of primary sensorimotor cortex [70]. SMA is hypoactivated and SMA-putamen connectivity is abnormal during motor behavior in PD patients [71,72], as well as in animal models of PD [14]. Less stimulusinduced deactivation of the PCC/precuneus and impaired connectivity between dorsomedian frontal cortex and striatum are also symptomatic of executive disorders as assessed by response latency [73].…”

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

“…The study of functional connectivity (FC) in PD is relatively young (Baudrexel et al, 2011;Göttlich et al, 2013;Hacker et al, 2012;Helmich et al, 2010;Luo et al, 2014;Poston and Eidelberg, 2012;Sharman et al, 2013;Wu et al, 2009Wu et al, , 2011aWu et al, , 2012Yu et al, 2013). An early study evaluating resting-state FC (rsFC) in PD showed that rsFC between the pre-supplementary motor area (pre-SMA) and putamen was decreased, whereas that between the pre-SMA and primary motor cortex (M1) was increased (Wu et al, 2011a).…”

“…An early study evaluating resting-state FC (rsFC) in PD showed that rsFC between the pre-supplementary motor area (pre-SMA) and putamen was decreased, whereas that between the pre-SMA and primary motor cortex (M1) was increased (Wu et al, 2011a). A recent study of striatal connectivity in PD patients (on medication) found decreased striatal connectivity to the extended brainstem, and weaker anticorrelations to the sensorimotor cortex, compared with normal controls (Hacker et al, 2012).…”

Causal effect of disconnection lesions on interhemispheric functional connectivity in rhesus monkeys

“…7-11), and detecting brain changes in disease. Functional connectivity changes have been identified in diverse conditions including Alzheimer's disease (6,(12)(13)(14), Parkinson's disease (15,16), multiple sclerosis (17,18), autism (19), depression (20,21), and schizophrenia (22,23).…”