Frequency‐specific alterations of regional homogeneity in subcortical stroke patients with different outcomes in hand function

Abstract

Emerging evidence has suggested that abnormalities in regional spontaneous brain activity following stroke may be detected by intrinsic low-frequency oscillations (LFO) in resting-state functional MRI (R-fMRI). However, the relationship between hand function outcomes following stroke and local LFO synchronization in different frequency bands is poorly understood. In this study, we performed R-fMRI to examine the regional homogeneity (ReHo) at three different frequency bands (slow-5: .01-.027 Hz; slow-4: .027-.08 Hz; and typical band: .01-.1 Hz) in 26 stroke patients with completely paralyzed hands (CPH) and 26 matched patients with partially paralyzed hands (PPH). Compared to the PPH group, decreased ReHo in the bilateral cerebellum posterior lobes and the contralesional cerebellum anterior lobe was observed in the slow-5 band and the slow-4 band in the CPH group, respectively. The mean ReHo values in these regions were positively correlated with the Fugl-Meyer assessment (FMA) scores. In contrast, increased ReHo in the contralesional supplementary motor area and the contralesional superior temporal gyrus was observed in the slow-4 band and the slow-5 band, respectively. The mean ReHo values in these regions were negatively correlated with the FMA scores. Importantly, significant interactions were identified between the frequency bands and the subgroups of patients in the contralesional precentral gyrus and middle frontal gyrus. These findings indicate that frequency-dependent R-fMRI patterns may serve as potential biomarkers of the neural substrates associated with hand function outcomes following stroke.

Dysfunctional white‐matter networks in medicated and unmedicated benign epilepsy with centrotemporal spikes

“…Second, most of alterations were not shared across sub‐bands, which implied a frequency‐dependent dysfunction connectivity of brain white matter in each sub‐band (Wang et al, ). Third, more differences were observed in the frequency band of Slow‐3 and Slow‐4, suggesting a correspondence between specific frequency and certain disease (Zhao, Tang et al, ; Zhou, Huang, Zhuang, Gao, & Gong, ). These inferences still need to be verified in future studies to elucidate frequency‐specific network organization mechanism.…”

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

“…Despite the fact that stroke frequently damages subcortical regions (Corbetta et al., 2015), empirical evidence regarding functional reorganization in chronic subcortical stroke patients with disparate hand outcomes is still scarce. Our previous studies have demonstrated that stroke patients suffering from partial hand paresis and complete hand paresis showed different neuroplasticity patterns in topological organization (Yin et al., 2014) and in frequency-dependent local spontaneous oscillations (Zhao et al., 2018a). These studies indicated that it is critical to consider the impact of the hand deficits on functional reorganization in chronic stroke, which may be helpful for understanding the neurophysiologic mechanisms of different hand outcomes after chronic stroke and motivating the development of noninvasive, targeted brain stimulation (Grefkes and Fink, 2012; Grefkes et al., 2010; Koch and Hummel, 2017).…”

“…Based on our previous studies among stroke subgroups (Yin et al., 2014; Zhao et al., 2018a) and the two studies that compared ICA networks between stroke patients and controls (Wang et al., 2014; Zhao et al., 2018b), we explored whether chronic stroke patients with a CPH would show more widespread FC reorganization within and between networks than those with a PPH, which might improve our pathophysiologic understanding of chronic stroke patients with different hand outcomes. Finally, we evaluated the associations between the performance of the paretic hand and the aberrant FC patterns within and between networks in chronic stroke patients.…”

Aberrant Brain Activity at Early Delay Stage Post-radiotherapy as a Biomarker for Predicting Neurocognitive Dysfunction Late-Delayed in Patients With Nasopharyngeal Carcinoma

“…This data-driven method provides analysis of the region-to-region interactions and voxel-by-voxel neural activity with remarkably high test-retest reliabilities at the functional level, based on the intrinsic activity of the resting brain (16). Accumulating evidence indicates that the regional properties of the intrinsic brain dynamics can reliably reflect aspects of cognitive function (17–19). Furthermore, increasingly more studies have suggested the potential of ReHo changes as a prognostic imaging tool to identify the disease-related progression treatment response and outcomes for various neuropsychiatric disorders (19–21).…”

“…Accumulating evidence indicates that the regional properties of the intrinsic brain dynamics can reliably reflect aspects of cognitive function (17–19). Furthermore, increasingly more studies have suggested the potential of ReHo changes as a prognostic imaging tool to identify the disease-related progression treatment response and outcomes for various neuropsychiatric disorders (19–21). Thus, the application of this method might be helpful for the better characterization of the relationship between the functional evolutional processes and the late-delayed cognitive dysfunction in post-RT NPC.…”