Altered intra‐ and inter‐network functional coupling of resting‐state networks associated with motor dysfunction in stroke

Abstract

Motor functions are supported through functional integration across the extended motor system network. Individuals following stroke often show deficits on motor performance requiring coordination of multiple brain networks; however, the assessment of connectivity patterns after stroke was still unclear. This study aimed to investigate the changes in intra- and inter-network functional connectivity (FC) of multiple networks following stroke and further correlate FC with motor performance. Thirty-three left subcortical chronic stroke patients and 34 healthy controls underwent resting-state functional magnetic resonance imaging. Eleven resting-state networks were identified via independent component analysis (ICA). Compared with healthy controls, the stroke group showed abnormal FC within the motor network (MN), visual network (VN), dorsal attention network (DAN), and executive control network (ECN). Additionally, the FC values of the ipsilesional inferior parietal lobule (IPL) within the ECN were negatively correlated with the Fugl-Meyer Assessment (FMA) scores (hand + wrist). With respect to inter-network interactions, the ipsilesional frontoparietal network (FPN) decreased FC with the MN and DAN; the contralesional FPN decreased FC with the ECN, but it increased FC with the default mode network (DMN); and the posterior DMN decreased FC with the VN. In sum, this study demonstrated the coexistence of intra- and inter-network alterations associated with motor-visual attention and high-order cognitive control function in chronic stroke, which might provide insights into brain network plasticity following stroke.

Dysconnectivity of Multiple Resting-State Networks Associated With Higher-Order Functions in Sensorineural Hearing Loss

“…Eleven RSNs were identified out of all 40 ICs by spatial correlations in accordance to previous research (Smith et al, 2009; Peraza et al, 2017; Huang et al, 2018; Zhao et al, 2018). The RSNs included these networks were AN, pDMN, aDMN, rFPN, lFPN, DAN, MVN, LVN, SMN, pTMN, and CB (Figure 2).…”

Disrupted Functional Network Connectivity Predicts Cognitive Impairment in Presbycusis Patients

“…As we know, the DMN controls both primary perception and advanced cognition and is responsible for the integration of these two (Zhao et al, 2018 ). Studies by Chen et al ( 2018 ) indicated that compared with healthy controls, patients with hearing impairment showed reduced spontaneous neuronal activity in the precuneus.…”

Diverse functional connectivity patterns of resting-state brain networks associated with good and poor hand outcomes following stroke

“…Moreover, several FC studies have revealed potential neural mechanisms of spontaneous and rehabilitation-driven motor recovery after stroke (Park et al., 2011; Rehme et al., 2011a; Volz et al., 2016). Motor execution requires functional interactions between distributed but related brain regions (Zhao et al., 2018b), and focal lesions may disrupt remote cortical networks and result in impaired functional processes (Siegel et al., 2016; Wang et al., 2014). However, to date, the nature and relevance of abnormal network reorganization for different hand outcomes after chronic subcortical stroke remain poorly understood.…”

“…Using the ICA approach, one study found that well-recovered stroke patients showed disrupted connectivity within and between networks in the sensory processing, dorsal attention, frontoparietal, and default mode networks (Wang et al., 2014). Another study found that stroke patients with severe to mild motor deficits showed abnormal connectivity in more widespread networks, such as the motor, visual, dorsal attention, executive control, and default mode networks (Zhao et al., 2018b). Furthermore, Zhao et al.…”

“…However, this relationship was not found in Wang's study (Wang et al., 2014). To further clarify these inconsistent findings (Wang et al., 2014; Zhao et al., 2018b), the present study used a large and homogeneous sample with only left subcortical chronic stroke to systematically explore the functional reorganization patterns across 26 patients with a completely paralyzed hand (CPH), 26 patients with a partially paralyzed hand (PPH) and 52 healthy controls at the level of macroscopic brain networks.…”