Resting state functional connectivity of the subthalamic nucleus in Parkinson's disease assessed using arterial spin‐labeled perfusion fMRI

Abstract

Neurophysiological changes within the cortico-basal ganglia-thalamocortical circuits appear to be a characteristic of Parkinson's disease (PD) pathophysiology. The subthalamic nucleus (STN) is one of the basal ganglia components showing pathological neural activity patterns in PD. In this study, perfusion imaging data, acquired noninvasively using arterial spin-labeled (ASL) perfusion MRI, were used to assess the resting state functional connectivity (FC) of the STN in 24 early-to-moderate PD patients and 34 age-matched healthy controls, to determine whether altered FC in the very low frequency range of the perfusion time signal occurs as a result of the disease. Our results showed that the healthy STN was functionally connected with other nuclei of the basal ganglia and the thalamus, as well as with discrete cortical areas including the insular cortex and the hippocampus. In PD patients, connectivity of the STN was increased with two cortical areas involved in motor and cognitive processes. These findings suggest that hyperconnectivity of the STN could underlie some of the motor and cognitive deficits often present even at early stages of the disease. The FC measures provided good discrimination between controls and patients, suggesting that ASL-derived FC metrics could be a putative PD biomarker.

Abnormal resting state functional connectivity in patients with chronic fatigue syndrome: an arterial spin-labeling fMRI study

“…A primary strength of this study is the use of ASL, which provides a non-invasive method of directly quantifying blood flow in whole brain or in specific ROIs [26 and 26 and 37 and 38]. Furthermore, temporal fluctuation in CBF (assessed in this case using ASL) appear to correspond to underlying patterns of neuronal activity [26 and 39].…”

“…This step reduces spatial correlations resulting from physiological noise. Specifically, the CBF signal in the ventricles reflects cardiac-induced signal fluctuations while the CBF signal in the white matter reflects the respiratory cycle [26]. CBF volumes were filtered using a low pass (< .07 Hz) filter.…”

Neuroimaging of Parkinson's disease: Expanding views

“…A combined ASL and morphometric study observed a pattern of “parietal cortical thinning and reduced precuneus perfusion” that appeared even in mild PD (Madhyastha et al, 2015: 1). A novel ASL perfusion approach has also been used to examine functional connectivity of the subthalamic nucleus in PD and indicated subthalamic nucleus hyperconnectivity with primary motor cortex and precuneus regions (Fernandez-Seara et al, 2015). …”

Imaging in Parkinson's Disease

“…These findings suggest that compensatory alterations within the corticostriatal network occur in PD with increased connectivity in the anterior putamen in comparison with the posterior putamen, consistent with the posterior putamen's earlier and greater dopaminergic dysfunction in PD . In addition to striatal network, increased functional connectivity between the subthalamic nucleus and cortex in PD has also been observed (Fernandez-Seara et al, 2015;Kahan et al, 2014). PDD patients showed selective disruption of corticostriatal connectivity (Seibert, Murphy, Kaestner, & Brewer, 2012), specifically, the connectivity of the so-called default mode network, was disrupted in PD patients with cognitive deficits (Disbrow et al, 2014;Gorges et al, 2015).…”