scholarly journals Acupuncture Modulates the Functional Connectivity of the Default Mode Network in Stroke Patients

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Yong Zhang ◽  
Kuangshi Li ◽  
Yi Ren ◽  
Fangyuan Cui ◽  
Zijing Xie ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Default Mode Network ◽  
Resting State Fmri ◽  
Brain Regions ◽  
Stroke Patients ◽  
Default Mode ◽  
Function Recovery ◽  
Abundant Evidence ◽  
Before And After ◽  
Hemispheric Infarction

Abundant evidence from previous fMRI studies on acupuncture has revealed significant modulatory effects at widespread brain regions. However, few reports on the modulation to the default mode network (DMN) of stroke patients have been investigated in the field of acupuncture. To study the modulatory effects of acupuncture on the DMN of stroke patients, eight right hemispheric infarction and stable ischemic stroke patients and ten healthy subjects were recruited to undergo resting state fMRI scanning before and after acupuncture stimulation. Functional connectivity analysis was applied with the bilateral posterior cingulate cortices chosen as the seed regions. The main finding demonstrated that the interregional interactions between the ACC and PCC especially enhanced after acupuncture at GB34 in stroke patients, compared with healthy controls. The results indicated that the possible mechanisms of the modulatory effects of acupuncture on the DMN of stroke patients could be interpreted in terms of cognitive ability and motor function recovery.

scholarly journals Altered functional connectivity in default mode network in absence epilepsy: A resting-state fMRI study

2011 ◽  
Vol 32 (3) ◽  
pp. 438-449 ◽  
Author(s):  
Cheng Luo ◽  
Qifu Li ◽  
Yongxiu Lai ◽  
Yang Xia ◽  
Yun Qin ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Default Mode Network ◽  
Resting State ◽  
Resting State Fmri ◽  
Absence Epilepsy ◽  
Default Mode ◽  
Fmri Study

scholarly journals Reduced Default Mode Network Functional Connectivity in Patients with Recurrent Major Depressive Disorder

2018 ◽  
Author(s):  
Chao-Gan Yan ◽  
Xiao Chen ◽  
Le Li ◽  
Francisco Xavier Castellanos ◽  
Tong-Jian Bai ◽  
...  
Keyword(s):  
Major Depressive Disorder ◽  
Functional Connectivity ◽  
Depressive Disorder ◽  
Default Mode Network ◽  
Resting State ◽  
Resting State Fmri ◽  
Research Groups ◽  
Major Depressive ◽  
Default Mode ◽  
Normal Controls

ABSTRACTMajor Depressive Disorder (MDD) is common and disabling, but its neuropathophysiology remains unclear. Most studies of functional brain networks in MDD have had limited statistical power and data analysis approaches have varied widely. The REST-meta-MDD Project of resting-state fMRI (R-fMRI) addresses these issues. Twenty-five research groups in China established the REST-meta-MDD Consortium by contributing R-fMRI data from 1,300 patients with MDD and 1,128 normal controls (NCs). Data were preprocessed locally with a standardized protocol prior to aggregated group analyses. We focused on functional connectivity (FC) within the default mode network (DMN), frequently reported to be increased in MDD. Instead, we found decreased DMN FC when we compared 848 patients with MDD to 794 NCs from 17 sites after data exclusion. We found FC reduction only in recurrent MDD, not in first-episode drug-naïve MDD. Decreased DMN FC was associated with medication usage but not with MDD duration. DMN FC was also positively related to symptom severity but only in recurrent MDD. Exploratory analyses also revealed alterations in FC of visual, sensory-motor and dorsal attention networks in MDD. We confirmed the key role of DMN in MDD but found reduced rather than increased FC within the DMN. Future studies should test whether decreased DMN FC mediates response to treatment. Finally, all resting-state fMRI indices of data contributed by the REST-meta-MDD consortium are being shared publicly via the R-fMRI Maps Project.SIGNIFICANCE STATEMENTFunctional connectivity within the default mode network in major depressive disorder patients has been frequently reported abnormal but with contradicting directions in previous small sample size studies. In creating the REST-meta-MDD consortium containing neuroimaging data of 1,300 depressed patients and 1,128 normal controls from 25 research groups in China, we found decreased default mode network functional connectivity in depressed patients, driven by patients with recurrent depression, and associated with current medication treatment but not with disease duration. These findings suggest that default mode network functional connectivity remains a prime target for understanding the pathophysiology of depression, with particular relevance to revealing mechanisms of effective treatments.

scholarly journals Nuisance Effects and the Limitations of Nuisance Regression in Dynamic Functional Connectivity fMRI

2018 ◽  
Author(s):  
Alican Nalci ◽  
Bhaskar D. Rao ◽  
Thomas T. Liu
Keyword(s):  
Functional Connectivity ◽  
Resting State Fmri ◽  
Brain Regions ◽  
Blood Oxygenation ◽  
Dynamic Functional Connectivity ◽  
Temporal Fluctuations ◽  
Before And After ◽  
The Difference ◽  
Time Courses ◽  
The Relationship

AbstractIn resting-state fMRI, dynamic functional connectivity (DFC) measures are used to characterize temporal changes in the brain’s intrinsic functional connectivity. A widely used approach for DFC estimation is the computation of the sliding window correlation between blood oxygenation level dependent (BOLD) signals from different brain regions. Although the source of temporal fluctuations in DFC estimates remains largely unknown, there is growing evidence that they may reflect dynamic shifts between functional brain networks. At the same time, recent findings suggest that DFC estimates might be prone to the influence of nuisance factors such as the physiological modulation of the BOLD signal. Therefore, nuisance regression is used in many DFC studies to regress out the effects of nuisance terms prior to the computation of DFC estimates. In this work we examined the relationship between DFC estimates and nuisance factors. We found that DFC estimates were significantly correlated with temporal fluctuations in the magnitude (norm) of various nuisance regressors, with significant correlations observed in the majority (76%) of the cases examined. Significant correlations between the DFC estimates and nuisance regressor norms were found even when the underlying correlations between the nuisance and fMRI time courses were relatively small. We then show that nuisance regression does not eliminate the relationship between DFC estimates and nuisance norms, with significant correlations observed in the majority (71%) of the cases examined after nuisance regression. We present theoretical bounds on the difference between DFC estimates obtained before and after nuisance regression and relate these bounds to limitations in the efficacy of nuisance regression with regards to DFC estimates.

scholarly journals Altered functional connectivity of the default mode network in diffuse gliomas measured with pseudo-resting state fMRI

2013 ◽  
Vol 116 (2) ◽  
pp. 373-379 ◽  
Author(s):  
Robert J. Harris ◽  
Susan Y. Bookheimer ◽  
Timothy F. Cloughesy ◽  
Hyun J. Kim ◽  
Whitney B. Pope ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Default Mode Network ◽  
Resting State ◽  
Resting State Fmri ◽  
Default Mode ◽  
Diffuse Gliomas

Task-positive Functional Connectivity of the Default Mode Network Transcends Task Domain

2015 ◽  
Vol 27 (12) ◽  
pp. 2369-2381 ◽  
Author(s):  
Amanda Elton ◽  
Wei Gao
Keyword(s):  
Functional Connectivity ◽  
Task Performance ◽  
Default Mode Network ◽  
Inferior Frontal Gyrus ◽  
Brain Regions ◽  
Positive Functional ◽  
Default Mode ◽  
Goal Directed Behavior ◽  
Increased Activity

The default mode network (DMN) was first recognized as a set of brain regions demonstrating consistently greater activity during rest than during a multitude of tasks. Originally, this network was believed to interfere with goal-directed behavior based on its decreased activity during many such tasks. More recently, however, the role of the DMN during goal-directed behavior was established for internally oriented tasks, in which the DMN demonstrated increased activity. However, the well-documented hub position and information-bridging potential of midline DMN regions indicate that there is more to uncover regarding its functional contributions to goal-directed tasks, which may be based on its functional interactions rather than its level of activation. An investigation of task-related changes in DMN functional connectivity during a series of both internal and external tasks would provide the requisite investigation for examining the role of the DMN during goal-directed task performance. In this study, 20 participants underwent fMRI while performing six tasks spanning diverse internal and external domains in addition to a resting-state scan. We hypothesized that the DMN would demonstrate “task-positive” (i.e., positively contributing to task performance) changes in functional connectivity relative to rest regardless of the direction of task-related changes in activity. Indeed, our results demonstrate significant increases in DMN connectivity with task-promoting regions (e.g., anterior insula, inferior frontal gyrus, middle frontal gyrus) across all six tasks. Furthermore, canonical correlation analyses indicated that the observed task-related connectivity changes were significantly associated with individual differences in task performance. Our results indicate that the DMN may not only support a “default” mode but may play a greater role in both internal and external tasks through flexible coupling with task-relevant brain regions.

scholarly journals Maladaptive Self-Focused Attention and Default Mode Network Connectivity: A Transdiagnostic Investigation Across Social Anxiety and Body Dysmorphic Disorders

2021 ◽  
Author(s):  
Angela Fang ◽  
Bengi Baran ◽  
Clare C Beatty ◽  
Jennifer Mosley ◽  
Jamie D Feusner ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Social Anxiety ◽  
Default Mode Network ◽  
Brain Regions ◽  
Posterior Cingulate Cortex ◽  
Focused Attention ◽  
Neural Basis ◽  
Default Mode ◽  
Body Dysmorphic Disorders ◽  
Primary Body

Abstract Maladaptive self-focused attention (SFA) is a bias toward internal thoughts, feelings, and physical states. Despite its role as a core maintaining factor of symptoms in cognitive theories of social anxiety and body dysmorphic disorders, studies have not examined its neural basis. In this study, we hypothesized that maladaptive SFA would be associated with hyperconnectivity in the default mode network (DMN) in self-focused patients with these disorders. Thirty patients with primary social anxiety disorder or primary body dysmorphic disorder, and 28 healthy individuals were eligible and scanned. Eligibility was determined by scoring greater than 1SD or below 1SD of the Public Self-Consciousness Scale normative mean, respectively, for each group. Seed-to-voxel functional connectivity was computed using a DMN posterior cingulate cortex (PCC) seed. There was no evidence of increased DMN functional connectivity in patients compared to controls. Patients (regardless of diagnosis) showed reduced functional connectivity of the PCC with several brain regions, including the bilateral superior parietal lobule (SPL), compared to controls, which was inversely correlated with maladaptive SFA but not associated with social anxiety, body dysmorphic, or depression severity, or rumination. Abnormal PCC-SPL connectivity may represent a transdiagnostic neural marker of SFA that reflects difficulty shifting between internal versus external attention.

scholarly journals Aberrant Interhemispheric Functional Connectivity in Diabetic Retinopathy Patients

2021 ◽  
Vol 15 ◽  
Author(s):  
Song Wan ◽  
Wen Qing Xia ◽  
Yu Lin Zhong
Keyword(s):  
Diabetic Retinopathy ◽  
Functional Connectivity ◽  
Default Mode Network ◽  
Brain Regions ◽  
Middle Temporal Gyrus ◽  
Coordination Pattern ◽  
Precentral Gyrus ◽  
Default Mode ◽  
Sensorimotor Network ◽  
Visual Network

Background: Accumulating lines of evidence demonstrated that diabetic retinopathy (DR) patients trigger abnormalities in brain’s functional connectivity (FC), whereas the alterations of interhemispheric coordination pattern occurring in DR are not well understood. Our study was to investigate alterations of interhemispheric coordination in DR patients.Methods: Thirty-four DR individuals (19 males and 15 females: mean age: 52.97 ± 8.35 years) and 37 healthy controls (HCs) (16 males and 21 females; mean age: 53.78 ± 7.24 years) were enrolled in the study. The voxel-mirrored homotopic connectivity (VMHC) method was conducted to investigate the different interhemispheric FC between two groups. Then, the seed-based FC method was applied to assess the different FCs with region of interest (ROI) in the brain regions of decreased VMHC between two groups.Results: Compared with HC groups, DR groups showed decreased VMHC values in the bilateral middle temporal gyrus (MTG), lingual/calcarine/middle occipital gyrus (LING/CAL/MOG), superior temporal gyrus (STG), angular (ANG), postcentral gyrus (PosCG), inferior parietal lobule (IPL), and precentral gyrus (PreCG). Meanwhile, altered FC includes the regions of auditory network, visual network, default mode network, salience network, and sensorimotor network. Moreover, a significant positive correlation was observed between the visual acuity-oculus dexter (OD) and zVMHC values in the bilateral LING/CAL/MOG (r = 0.551, p = 0.001), STG (r = 0.426, p = 0.012), PosCG (r = 0.494, p = 0.003), and IPL (r = 0.459, p = 0.006) in DR patients.Conclusion: Our results highlighted that DR patients were associated with substantial impairment of interhemispheric coordination in auditory network, visual network, default mode network, and sensorimotor network. The VMHC might be a promising therapeutic target in the intervention of brain functional dysfunction in DR patients.

Abstract 19: Default Mode Network Alterations in Cerebral Amyloid Angiopathy: A Resting State FMRI Study

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Mitchell J Horn ◽  
Elif Gokcal ◽  
Aina Frau-Pascual ◽  
Kristin M Schwab ◽  
Anand Viswanathan ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Cerebral Amyloid Angiopathy ◽  
Default Mode Network ◽  
Resting State ◽  
Resting State Fmri ◽  
Amyloid Angiopathy ◽  
Healthy Controls ◽  
Default Mode ◽  
Posterior Cingulate ◽  
Cerebral Amyloid

Introduction: Cerebral amyloid angiopathy (CAA) is an established cause of intracerebral hemorrhage and vascular dysfunction leading to ischemia. Functional connectivity analysis using MRI is becoming an important tool to analyze the brain activity during resting state, the default mode network (DMN) representing the prototypical set of connections. As CAA pathology has a posterior predominance, we sought to characterize the functional connectivity of the posterior DMN at resting state in patients with CAA. Methods: Patients with probable CAA diagnosed using Boston Criteria and healthy controls (HC) were prospectively enrolled and received high resolution 3T MRI scans including dedicated resting-state fMRI sequences. Functional seed-to-seed analyses were done using the default processing pipeline in the CONN Toolbox. Correlation maps between the established DMN and specific regions of the posterior DMN, the precuneus and posterior cingulate, were averaged within groups and compared in an ANCOVA model. Results: Study participants consisted of 60 patients with probable CAA and 20 healthy controls [aged 69 ± 7.5 vs 72.3 ± 8 years, P = 0.108]. Seed-to-seed analysis revealed a significantly lower strength of DMN connectivity in CAA when compared to controls in the precuneus [ P = 0.009] and posterior cingulate [ P = 0.003] adjusted for age and sex (Fig 1). Conclusion: Patients with CAA exhibited significant loss of connectivity in the posterior regions of the DMN when compared to controls. The precuneus and posterior cingulate are core regions of the DMN with reportedly high metabolic rates at rest. Disruption of these posterior DMN regions might occur due to vascular amyloid pathology that shows a predominantly posterior distribution.

Sign in / Sign up

Export Citation Format

Share Document