Mean Degree Centrality Values Research Articles

Spontaneous changes in brain network centrality in patients with pathological myopia: A voxel-wise degree centrality analysis.

Myopia has become a worldwide problem that endangers public health and adds a serious socioeconomic burden. Current research has focused on the pathogenesis and manifestations of pathological myopia (PM). However, few studies have been conducted on the spontaneous activity of the patient's brain. To study the potential brain network activity in patients with PM by the degree centrality (DC) method. This experiment included 15 PM patients and 15 healthy controls (HCs). Every participant experienced a resting-state functional magnetic resonance imaging (rs-fMRI) scan. Receiver operating characteristic (ROC) curve analysis was used to distinguish between PM patients and HCs. Correlation analysis was used to explore the relationships between mean DC values and clinical performance in different brain regions. It showed that patients with PM had lower DC values in the right fusiform gyrus (FR) and right cingulate (CAR). The ROC curve was used to indicate the accuracy of the correlation. It showed that in PM group, left best corrected visual acuity (BCVA-L) and right best corrected visual acuity (BCVA-R) were negatively correlated with the DC value of FR. The occurrence of PM is mainly related to the abnormal activity of the fusiform and cingulum. DC value might be used as a biological marker of abnormal brain activity in PM patients.

Altered voxel-level whole-brain functional connectivity in multiple system atrophy patients with depression symptoms

BackgroundIt is yet unknown if the whole-brain resting-state network is altered in multiple system atrophy with symptoms of depression. This study aimed to investigate if and how depression symptoms in multiple system atrophy are associated with resting-state network dysfunction.MethodsWe assessed the resting-state functional network matric using Degree centrality (DC) coupling with a second ROI-wise functional connectivity (FC) algorithm in a multimodal imaging case-control study that enrolled 32 multiple system atrophy patients with depression symptoms (MSA-D), 30 multiple system atrophy patients without depression symptoms (MSA-ND), and 34 healthy controls (HC).ResultsCompared to HC, MSA-D showed more extensive DC hub dysfunction in the left precentral and right middle frontal cortex than MSA-ND. A direct comparison between MSA-D and MSA-ND detected increased DC in the right anterior cingulum cortex, but decreased DC in the left cerebellum lobule IV and lobule V, left middle pole temporal cortex, and right superior frontal cortex. Only right anterior cingulum cortex mean DC values showed a positive correlation with depression severity, and used ACC as seed, a second ROI-wise functional connectivity further revealed MSA-D patients showed decreased connectivity between the ACC and right thalamus and right middle temporal gyrus (MTG).ConclusionsThese findings revealed that dysfunction of rACC, right middle temporal lobe and right thalamus involved in depressed MSA. Our study might help to the understanding of the neuropathological mechanism of depression in MSA.

Spontaneous functional changes in specific cerebral regions in patients with hypertensive retinopathy: a resting-state functional magnetic resonance imaging study.

This study investigated functional alterations in the cerebral network of patients with hypertensive retinopathy (HR) by resting-state functional magnetic resonance imaging (rs-fMRI) and degree centrality (DC) methods. 31 patients with HR along with 31 healthy controls (HC) closely matched in gender and age were enrolled for the research. All participants were examined by rs-fMRI, and the DC method was applied to evaluate alterations in spontaneous cerebral activity between the 2 groups. We used the independent samples t test to evaluate demographic and general information differences between HR patients and HCs. The 2-sample t test was used to compare the DC values of different cerebral regions between the 2 groups. The accuracy of differential diagnostic HR was analyzed by receiver operating characteristic (ROC) curve method for rs-fMRI DC values changes. Pearson’s correlation coefficient was applied to determine the correlation between differences in DC in specific cerebral areas and clinical manifestation. Results showed that DC values were higher in the left cerebellum posterior lobe (LCPL), left medial occipital gyrus (LMOG), and bilateral precuneus (BP) of HR patients compared to HCs. Mean DC values were lower in the right medial frontal gyrus/bilateral anterior cingulate cortex of HR patients. Anxiety and depression scores were positively correlated with DC values of LMOG and LCPL, respectively. Bilateral best-corrected visual acuity in HR patients was negatively correlated with the DC value of BP. Hence, changes in DC in specific cerebral areas of patients with HR reflect functional alterations that provide insight into the pathophysiologic mechanisms of HR.

Altered brain network centrality in middle-aged patients with retinitis pigmentosa: A resting-state functional magnetic resonance imaging study.

ObjectiveThe purpose of this study is to explore the underlying functional network brain activity changes of patients in middle‐aged with retinitis pigmentosa (RP) and the relationships with clinical features such as depression scale and visual functioning using voxel‐wise degree centrality (DC) method.MethodsWe included 16 patients with RP (11 men, 5 women) and 16 healthy controls (HCs; 11 men, 5 women). Participants were matched in terms of age, weight, gender and handedness (age and weight between the two groups were compared using independent sample t‐tests, gender and handedness were compared using chi‐square test). We use the voxel‐wise DC method to assess spontaneous brain activity. Receiver operating characteristic (ROC) curve analysis was performed to distinguish between RP patients and HCs. Correlation analysis was used to examine the relationships between mean DC values in various brain regions and clinical features (such as depression scale and visual functioning) in RP patients.ResultsCompared with HCs, the DC values of patients with RP were reduced in the right medial frontal gyrus, bilateral cuneus, bilateral precuneus, and bilateral superior frontal gyrus, and increased in the right cerebellum posterior lobe, left inferior temporal gyrus, and right fusiform gyrus. The mean DC values in the bilateral cuneus negatively correlated with the depression scale, and those in the bilateral precuneus positively correlated with the Visual Functioning Questionnaire‐25.ConclusionsMiddle‐aged patients with RP exhibit abnormal brain network activity in various brain regions, and this may underlie the pathological mechanism of RP.

Alterations in Degree Centrality and Functional Connectivity in Parkinson's Disease Patients With Freezing of Gait: A Resting-State Functional Magnetic Resonance Imaging Study.

ObjectiveFreezing of gait (FOG) is a common disabling motor symptom in Parkinson’s disease (PD), but the potential pathogenic mechanisms are still unclear.MethodsA total of 22 patients with PD with FOG (PD-FOG), 28 patients with PD without FOG (PD-nFOG), and 33 healthy controls (HCs) were recruited in this study. Degree centrality (DC)—a graph theory-based measurement of global connectivity at the voxel level by measuring the number of instantaneous functional connections between one region and the rest of the brain—can map brain hubs with high sensitivity, specificity, and reproducibility. DC was used to explore alterations in the centrality of PD-FOG correlated with brain node levels. PD-FOG cognitive network dysfunction was further revealed via a seed-based functional connectivity (FC) analysis. In addition, correlation analyses were carried out between clinical symptoms and acquired connectivity measurement.ResultsCompared to the PD-nFOG group, the PD-FOG group showed remarkably increased DC values in the right middle frontal gyrus (RMFG). There were no significant differences in other gray matter regions. Importantly, the clinical severity of FOG was related to the mean DC values in the RMFG. This brain region served as a seed in secondary seed-based FC analysis, and we further found FC changes in the right precuneus, right inferior frontal gyrus, right superior frontal gyrus (SFG), and cerebellum.ConclusionIncreased RMFG activity and FC network alterations in the middle frontal cortex with the precuneus, inferior, and SFG, and the cerebellum may have great potential in brain dysfunction in PD with FOG.

Altered resting-state voxel-level whole-brain functional connectivity in multiple system atrophy patients with cognitive impairment

ObjectiveThere is increasing evidence of cognitive impairment (CI) frequently occurring in patients with multiple system atrophy (MSA); however, the neurobiological mechanisms underlying CI in patients with MSA remain unclear. MethodsWe enrolled 61 patients with probable MSA and 33 healthy controls (HC). We used degree centrality (DC) analysis to assess changes in the centrality level of MSA-CI related brain nodes. We conducted a secondary seed-based functional connectivity (FC) analysis to investigate dysfunctions in cognitive networks related to MSA. Further, we analysed the correlation between clinical symptoms and acquired connectivity measures. ResultsCompared with HC, patients with MSA-CI and those with MSA with normal cognition (MSA-NCI) exhibited lower DC values in the left calcarine and right postcentral regions and higher DC values in the bilateral caudate and left precuneus. There were significant differences in the DC values in the right middle prefrontal gyrus between the MSA-CI and MSA-NCI groups. The mean DC values in the right middle prefrontal gyrus (RMPFG) were correlated with clinical cognitive severity. Consequently, we used this brain region as a seed in secondary seed-based FC analysis and observed FC changes within the right precuneus, inferior parietal lobe, and right insula. ConclusionsDecreased middle prefrontal cortex activity and its altered functional connectivity with the precuneus, inferior parietal lobe, and insula are possible biomarkers of cognitive dysfunction in patients with MSA-CI. SignificanceCognitive impairment in MSA is associated with alterations in the dorsolateral prefrontal cortex network.

Network change in the ipsilesional cerebellum is correlated with motor recovery following unilateral pontine infarction.

Patients with acute pontine infarcts generally have good short-term motor outcomes; however, the mechanisms underlying this recovery of function remain unclear. Twenty well-recovered patients with acute pontine infarcts and 20 well-recovered patients with acute striato-capsular infarcts were recruited. Fugl-Meyer assessment and resting-state functional magnetic resonance imaging were performed 1, 4 and 12weeks after onset. Patients were further assigned to better and worse recovery subgroups according to the degree of motor recovery at the twelfth week after stroke. Voxel-wise degree centrality (DC)-behavior correlation analysis was used to identify brain regions related to changes in motor function within 12weeks after stroke. A significant correlation was found between DC and Fugl-Meyer scores within 12weeks in the ipsilesional cerebellar crus I and crus II in patients with pontine infarction and in the ipsilesional middle temporal gyrus in patients with striato-capsular infarction (all P<0.001, AlphaSim corrected). The mean DC in these areas was higher both in the better and worse recovery subgroups at the fourth than at the first week (all P<0.05). In addition, the mean DC values in these areas were higher in patients with better recovery at the twelfth than at the first week (P<0.05), but such change was not found in patients with worse recovery. These results indicate that network changes in the ipsilesional cerebellum are correlated with motor recovery following pontine infarction. Motor recovery mechanisms may vary between pontine and striato-capsular infarcts, according to lesion location.

Abnormal intrinsic functional network hubs and connectivity following peripheral visual loss because of inherited retinal degeneration.

Previous neuroimaging studies have shown that the long-term effects of peripheral vision loss lead to functional and morphological reorganization in visual cortices. However, it has not been determined whether whole-brain functional network centrality changes occur during peripheral vision loss. This study aimed to investigate functional network centrality and connectivity changes in individuals with peripheral vision loss because of retinitis pigmentosa (RP) by using voxel-wise degree centrality (DC) and seed-based resting-state functional connectivity (rsFC) methods. In total, 30 RP patients (18 men and 12 women, mean age: 38.77±14.44 years) and 30 healthy controls (HCs) (18 men and 12 women, mean age: 34.57±10.70 years) matched for age, sex, cognition, education, and visual expertise underwent resting-state magnetic resonance imaging scans. Graph theory-based network analysis was carried out to investigate DC between the two groups. A seed-based rsFC analysis was then carried out to further reveal the abnormal functional connectivity of the altered DC brain region. Pearson's correlation was used to analyze the relationships of DC and rsFC index with the clinical variables in RP patients: visual function (best-corrected visual acuity and visual field, VF) and optical coherence tomography testing (mean retinal nerve fiber layer). Compared with HCs, RP patients had significantly lower DC values in the bilateral cuneus/calcarine/precuneus (CUN/CAL/PreCUN) [Brodmann's area (BA) 17/18/19/30/31]. In addition, RP patients showed decreased rsFC index, relative to that of HCs, from bilateral CUN/CAL/PreCUN to bilateral lingual/cuneus/calcarine (LIG/CUN/CAL) (BA 18/19/30) and the bilateral postcentral gyrus/superior parietal lobule (BA 3/5/7/40). In contrast, RP patients showed increased rsFC index, relative to that of HCs, from bilateral CUN/CAL/PreCUN to bilateral thalamus/caudate (voxel-level P<0.01; Gaussian random-field correction, cluster-level P<0.05). Moreover, the course of RP showed a negative correlation with the mean DC values of the bilateral CUN/CAL/PreCUN (r=-0.480; P=0.007) and the mean FC values of the bilateral LIG/CUN/CAL (r=-0.484; P=0.007); the mean DC values of the bilateral CUN/CAL/PreCUN in RP showed a negative correlation with the right eye VF (r=-0.411; P=0.024) and left eye VF (r=-0.426; P=0.019). Our results showed that RP patients showed abnormal function network hubs in various brain regions related to visual, thalamocortical, and sensorimotor networks; these might reflect impaired top-down modulations, visual imagery, and visuomotor coordination in RP patients. Moreover, the DC index can be used as a biomarker to indicate the severity of visual loss in RP patients.

Evidence of altered brain network centrality in patients with diabetic nephropathy and retinopathy: an fMRI study using a voxel-wise degree centrality approach.

Background:Over recent years, some researchers believe that diabetic nephropathy (DN) and diabetic retinopathy (DR) both independently increase the incidence of brain diseases, such as stroke, cerebral infarction, and cerebral hemorrhage. In the present study, we used the voxel-wise degree centrality (DC) method to investigate potential changes of functional network brain activity in patients with DN and retinopathy (DNR).Methods:Twenty DNR patients (9 men, 11 women) and 20 healthy controls (HCs; 9 men, 11 women) were recruited; the controls were matched for age, sex, and educational background. All subjects underwent resting-state functional magnetic resonance imaging. Ophthalmoscopy, renal biopsy and single-photon emission computed tomography were used to evaluate microvascular lesions in the eye and kidney. Data were categorized using receiver operating characteristic curves, and correlation analysis was performed using Pearson’s correlation analysis.Results:Compared with HCs, DNR patients showed reduced mean DC values in the right inferior temporal gyrus (RITG) and left subcallosal gyrus regions (LSG) and increased mean DC values in the bilateral precuneus (BP). Moreover, mean DC in the BP was correlated with renal estimated glomerular filtration rate (eGFR; r = 0.762). The area under the curve (AUC) value was 0.829 for BP and 0.839 for RITG and LSG.Conclusion:DNR patients showed dysfunction in three different brain regions. The linear correlation between eGFR and mean brain DC values indicates the presence of common diabetic microangiopathy in the brain and kidney, which may provide new ideas for multiorgan microvascular lesions of diabetics.

Altered brain network centrality in patients with late monocular blindness: a resting-state fMRI study.

IntroductionThe aim of the study was to investigate the underlying functional network brain activity changes in patients with late monocular blindness (MB) and the relationship with their clinical features using the voxel-wise degree centrality (DC) method.Material and methodsA total of 32 patients with MB (25 males and 7 females), and 32 healthy controls (HCs) (25 males and 7 females) closely matched in age, sex, and education, underwent resting-state functional magnetic resonance imaging scans. The DC method was used to assess local features of spontaneous brain activity. Correlation analysis was performed to explore the relationships between the observed mean DC signal values of the different areas and clinical features in these patients.ResultsCompared with HCs, MB patients had significantly lower DC values in the bilateral cuneus/V1/V2, and significantly higher DC values in the left inferior temporal gyrus and bilateral medial frontal gyrus. However, there was no relationship between the observed mean DC values of the different brain areas and the behavioral performance.ConclusionsLate monocular blindness involves brain function network dysfunction in many regions, which might indicate impairment of the visual cortex and other vision-related brain regions in the MBs.

Abnormal resting-state functional network centrality in patients with high myopia: evidence from a voxel-wise degree centrality analysis.

To investigate the functional networks underlying the brain-activity changes of patients with high myopia using the voxel-wise degree centrality (DC) method. In total, 38 patients with high myopia (HM) (17 males and 21 females), whose binocular refractive diopter were -6.00 to -7.00 D, and 38 healthy controls (17 males and 21 females), closely matched in age, sex, and education levels, participated in the study. Spontaneous brain activities were evaluated using the voxel-wise DC method. The receiver operating characteristic curve was measured to distinguish patients with HM from healthy controls. Correlation analysis was used to explore the relationship between the observed mean DC values of the different brain areas and the behavioral performance. Compared with healthy controls, HM patients had significantly decreased DC values in the right inferior frontal gyrus/insula, right middle frontal gyrus, and right supramarginal/inferior parietal lobule (P<0.05). In contrast, HM patients had significantly increased DC values in the right cerebellum posterior lobe, left precentral gyrus/postcentral gyrus, and right middle cingulate gyrus (P<0.05). However, no relationship was found between the observed mean DC values of the different brain areas and the behavioral performance (P>0.05). HM is associated with abnormalities in many brain regions, which may indicate the neural mechanisms of HM. The altered DC values may be used as a useful biomarker for the brain activity changes in HM patients.

Alterations of resting-state functional network centrality in patients with asthma: evidence from a voxel-wise degree centrality analysis.

Several previous studies have reported that asthma patients have abnormal brain activities, whereas alterations in the resting-state network still remain unknown. The aim of this study was to investigate the changes in functional network centrality in asthma patients using voxel-wise degree centrality (DC) method. Asthma patients and healthy controls (HCs) were matched closely in age, sex, and education of participants. The DC method was used to evaluate the functional network centrality. The receiver operating characteristic curve was used to distinguish the asthma group from the HCs group. The Pearson correlation coefficient was used to explore the relationship between the observed mean values of DC in different brain areas and the behavioral performance. Compared with HCs, DC values were significantly decreased in the right middle temporal gyrus and the right putamen of asthma patients. In contrast, in asthma patients, DC values were markedly increased in the right posterior lobe of the cerebellum, right inferior temporal gyrus, left superior frontal gyrus, left postcentral gyrus and inferior parietal lobule, left middle frontal gyrus, and left postcentral gyrus. However, there was no relationship between the observed mean DC values in different brain areas and the behavioral performance. The results showed that the DC values were altered in various brain regions of asthma patients, which were related to default mode network, the cortex-basal ganglia network, the frontoparietal network, and the sensorimotor network, leading to some useful information for clinical studies in asthma patients.

Network centrality in patients with acute unilateral open globe injury: A voxel‑wise degree centrality study.

The present study aimed to investigate functional networks underlying brain‑activity alterations in patients with acute unilateral open globe injury (OGI) and associations with their clinical features using the voxel‑wise degree centrality (DC) method. In total, 18patients with acute OGI (16 males and 2 females), and 18 healthy subjects (16 males and 2 females), closely matched in age, sex and education, participated in the present study. Each subject underwent a resting‑state functional magnetic resonance imaging scan. The DC method was used to assess local features of spontaneous brain activity. Receiver operating characteristic curve analysis was used to distinguish OGIs from healthy controls (HCs). Correlation analysis was used to examine the association between the observed mean DC values of different brain areas and behavioral performance. Compared with HCs, patients with acute unilateral OGI had significantly increased DC values in the bilateral primary visual cortex (V1/V2) and left precuneus (PCUN), and significantly decreased DC values in the right insula, left insula, right inferior parietal lobule (IPL)/supramarginal gyrus (SMG), IPL/SMG, right supplementary motor area and right postcentral gyrus. Additionally, in the acute OGI group, it was observed that the duration of OGI was negatively correlated with the DC signal value of the bilateral V1/V2 (r=‑0.581; P=0.011) and left PCUN (r=‑0.508; P=0.031). Acute OGI led to brain functional network dysfunction in a number of brain regions, which may indicate impairment of the visual cortex and other vision‑associated brain regions in OGI.

Altered brain network centrality in patients with adult comitant exotropia strabismus: A resting-state fMRI study.

ObjectiveTo investigate the underlying functional network brain-activity changes in patients with adult comitant exotropia strabismus (CES) and the relationship with clinical features using the voxel-wise degree centrality (DC) method.MethodsA total of 30 patients with CES (17 men, 13 women), and 30 healthy controls (HCs; 17 men, 13 women) matched in age, sex, and education level participated in the study. DC was used to evaluate spontaneous brain activity. Receiver operating characteristic (ROC) curve analysis was conducted to distinguish CESs from HCs. The relationship between mean DC values in various brain regions and behavioral performance was examined with correlation analysis.ResultsCompared with HCs, CES patients exhibited decreased DC values in the right cerebellum posterior lobe, right inferior frontal gyrus, right middle frontal gyrus and right superior parietal lobule/primary somatosensory cortex (S1), and increased DC values in the right superior temporal gyrus, bilateral anterior cingulate, right superior temporal gyrus, and left inferior parietal lobule. However, there was no correlation between mean DC values and behavioral performance in any brain regions.ConclusionsAdult comitant exotropia strabismus is associated with abnormal brain network activity in various brain regions, possibly reflecting the pathological mechanisms of ocular motility disorders in CES.