scholarly journals Functional Connectivity Between Anterior Insula and Key Nodes of Frontoparietal Executive Control and Salience Networks Distinguish Bipolar Depression From Unipolar Depression and Healthy Control Subjects

2018 ◽  
Vol 3 (5) ◽  
pp. 473-484 ◽  
Author(s):  
Kristen K. Ellard ◽  
Jared P. Zimmerman ◽  
Navneet Kaur ◽  
Koene R.A. Van Dijk ◽  
Joshua L. Roffman ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Executive Control ◽  
Bipolar Depression ◽  
Unipolar Depression ◽  
Anterior Insula ◽  
Control Subjects ◽  
Healthy Control ◽  
Key Nodes

scholarly journals Dynamic functional connectivity changes associated with dementia in Parkinson’s disease

Brain ◽  
2019 ◽  
Vol 142 (9) ◽  
pp. 2860-2872 ◽  
Author(s):  
Eleonora Fiorenzato ◽  
Antonio P Strafella ◽  
Jinhee Kim ◽  
Roberta Schifano ◽  
Luca Weis ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Functional Connectivity ◽  
Parkinson’S Disease Dementia ◽  
Dynamic Functional Connectivity ◽  
Control Subjects ◽  
Healthy Control ◽  
Normal Cognition

AbstractDynamic functional connectivity captures temporal variations of functional connectivity during MRI acquisition and it may be a suitable method to detect cognitive changes in Parkinson’s disease. In this study, we evaluated 118 patients with Parkinson’s disease matched for age, sex and education with 35 healthy control subjects. Patients with Parkinson’s disease were classified with normal cognition (n = 52), mild cognitive impairment (n = 46), and dementia (n = 20) based on an extensive neuropsychological evaluation. Resting state functional MRI and a sliding-window approach were used to study the dynamic functional connectivity. Dynamic analysis suggested two distinct connectivity ‘States’ across the entire group: a more frequent, segregated brain state characterized by the predominance of within-network connections, State I, and a less frequent, integrated state with strongly connected functional internetwork components, State II. In Parkinson’s disease, State I occurred 13.89% more often than in healthy control subjects, paralleled by a proportional reduction of State II. Parkinson’s disease subgroups analyses showed the segregated state occurred more frequently in Parkinson’s disease dementia than in mild cognitive impairment and normal cognition groups. Further, patients with Parkinson’s disease dementia dwelled significantly longer in the segregated State I, and showed a significant lower number of transitions to the strongly interconnected State II compared to the other subgroups. Our study indicates that dementia in Parkinson’s disease is characterized by altered temporal properties in dynamic connectivity. In addition, our results show that increased dwell time in the segregated state and reduced number of transitions between states are associated with presence of dementia in Parkinson’s disease. Further studies on dynamic functional connectivity changes could help to better understand the progressive dysfunction of networks between Parkinson’s disease cognitive states.

Interhemispheric resting state functional connectivity abnormalities in unipolar depression and bipolar depression

2015 ◽  
Vol 17 (5) ◽  
pp. 486-495 ◽  
Author(s):  
Ying Wang ◽  
Shuming Zhong ◽  
Yanbin Jia ◽  
Zhifeng Zhou ◽  
Bing Wang ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Bipolar Depression ◽  
Unipolar Depression ◽  
Resting State Functional Connectivity

22 Whole-brain functional connectivity based on the graph theory analysiisn Psychogenic Non-Epileptic Seizures (PNES)

2020 ◽  
Vol 91 (8) ◽  
pp. e17.1-e17
Author(s):  
M Arbabi ◽  
S Amiri ◽  
F Badragheh ◽  
MM Mirbagheri ◽  
AA Asadi-Pooya
Keyword(s):  
Graph Theory ◽  
Functional Connectivity ◽  
Brain Networks ◽  
Epileptic Seizures ◽  
Brain Regions ◽  
Control Subjects ◽  
Wide Range ◽  
Healthy Control ◽  
Left And Right ◽  
Brain Functional Connectivity

ObjectiveDespite being the subject of many studies over the past two decades, mechanisms underlying psychogenic non-epileptic seizures (PNES) are still poorly understood. We tried to address this issue by utilizing brain functional connectivity analysis to identify brain regions with abnormal activities in patients with PNES. In a case-control study, we performed graph based network analysis, a robust technique that determines the organization of brain connectivity and characterizes topological properties of the brain networks.MethodsTwelve individuals with PNES and twenty-one healthy control subjects were examined. Resting state functional magnetic resonance imaging (rsfMRI) was acquired. All subjects were asked to keep their eyes open during the scanning process. The rsfMRI analysis consisted of pre-processing, extracting the functional connectivity matrix (FCM) based on the AAL atlas, threshold for binary FCM, constructing a graph network from FCM and extracting graph features, and finally statistical analysis. For all cortical and subcortical regions of the AAL atlas, we calculated measures of ‘degree,’ which is one of the features of the graph theory. Results: Our results revealed that, as compared to the healthy control subjects, patients with PNES had a significantly lower degree in some brain regions including their left and right insula (INS), right Putamen (PUT), left and right Supramarginal gyrus (SMG), right Middle occipital gyrus (MOG), and left and right Rolandic operculum (ROL). In contrast, degree was significantly greater in two regions [i.e., right Caudate (CAU) and left Inferior frontal gyrus orbital part (ORBinf)] in patients with PNES compared to that in controls.ConclusionOur findings suggest that functional connectivity of several major brain regions are different in patients with PNES compared with that in healthy individuals. While there is hypoactivity in regions important in perception, motor control, self- awareness, and cognitive functioning (e.g., insula) and also movement regulation (e.g., putamen), there is hyperactivity in areas involved in feedback processing (i.e., using information from past experiences to influence future actions and decisions) (e.g., caudate) in patients with PNES. The observation that individuals with PNES suffer from a wide range of abnormal activities in functional connectivity of their brain networks is consistent with the fact that PNES occur in a heterogeneous patient population; no single mechanism or contributing factor could explain PNES in all patients.

scholarly journals Correcting Cardiorespiratory Noise in Resting-state Functional MRI Data Acquired in Critically Ill Patients

2021 ◽  
Author(s):  
Suk-tak Chan ◽  
William R Sanders ◽  
David J Fischer ◽  
John E Kirsch ◽  
Vitaly Napadow ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Functional Mri ◽  
Critically Ill ◽  
Critically Ill Patients ◽  
Resting State ◽  
Brain Injuries ◽  
Control Subjects ◽  
Healthy Control ◽  
Severe Tbi ◽  
And Control

Resting-state functional MRI (rs-fMRI) is being used to develop diagnostic, prognostic, and therapeutic biomarkers for critically ill patients with severe brain injuries. In studies of healthy volunteers and non-critically ill patients, prospective cardiorespiratory data are routinely collected to remove non-neuronal fluctuations in the rs-fMRI signal during analysis. However, the feasibility and utility of collecting cardiorespiratory data in critically ill patients on a clinical MRI scanner are unknown. We concurrently acquired rs-fMRI (TR=1250ms), cardiac and respiratory data in 23 critically ill patients with acute severe traumatic brain injury (TBI), and 12 healthy control subjects. We compared the functional connectivity results after denoising with cardiorespiratory data (i.e., RETROICOR) with the results obtained after standard bandpass filtering. Rs-fMRI data in 7 patients could not be analyzed due to imaging artifacts. In 6 of the remaining 16 patients (37.5%), cardiorespiratory data were either incomplete or corrupted. In both patients and control subjects, the functional connectivity corrected with RETROICOR did not significantly differ from that corrected with bandpass filtering of 0.008-0.125 Hz. Collectively, these findings suggest that there is a limited feasibility and utility to prospectively acquire high-quality cardiorespiratory data during rs-fMRI in critically ill patients with severe TBI for physiological correction.

scholarly journals Altered Neurochemical Ingredient of Hippocampus in Patients with Bipolar Depression

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Murad Atmaca ◽  
Hanefi Yildirim
Keyword(s):  
Bipolar Disorder ◽  
Bipolar Depression ◽  
Hospital Staff ◽  
First Episode ◽  
Resonance Spectroscopy ◽  
Control Subjects ◽  
Healthy Control ◽  
Axis I ◽  
Dsm Iv ◽  
Lower Ratio

Background. In a number of investigations, hippocampal neurochemicals were evaluated in the patients with bipolar disorder who were on their first episode or euthymic periods. However, we did not meet any investigation in which only patients with bipolar depression were examined. As a consequence, the objective of the present study was to examine both sides of hippocampus of patients with bipolar disorder in depressive episode and healthy controls using1H-MRS.Methods. Thirteen patients with DSM-IV bipolar I disorder, most recent episode depressed, were recruited from the Department of Psychiatry at Firat University School of Medicine. We also studied 13 healthy comparison subjects who were without any DSM-IV Axis I disorders recruited from the hospital staff. The patients and controls underwent proton magnetic resonance spectroscopy (1H-MRS) of their hippocampus. NAA, CHO, and CRE values were measured.Results. No significant effect of diagnosis was observed for NAA/CRE ratio. For the NAA/CHO ratio, the ANCOVA with age, gender, and whole brain volume as covariates revealed that the patients with bipolar depression had significantly lower ratio compared to healthy control subjects for right and for left side. As for the CHO/CRE ratio, the difference was statistically significant for right side, with an effect diagnosis ofF= 4.763,P= 0.038, and was very nearly significant for left side, with an effect diagnosis ofF= 3.732,P= 0.064.Conclusions. We found that the patients with bipolar depression had lower NAA/CHO and higher CHO/CRE ratios compared to those of healthy control subjects. The findings of the present study also suggest that there may be a degenerative process concerning the hippocampus morphology in the patients with bipolar depression.

Enhancement of Platelet Sensitivity to ADP-Aggregation by Isometric Exercise in Arteriosclerotic Patients and its Prevention

1977 ◽  
Vol 37 (02) ◽  
pp. 329-338 ◽  
Author(s):  
Tadahiro Sano ◽  
Takeshi Motomiya ◽  
Hiroh Yamazaki ◽  
Takio Shimamoto
Keyword(s):  
Cyclic Amp ◽  
Mechanical Stress ◽  
Optical Density ◽  
Platelet Function ◽  
Isometric Exercise ◽  
Phosphodiesterase Inhibitor ◽  
New Method ◽  
Platelet Aggregability ◽  
Control Subjects ◽  
Healthy Control

SummaryA new method for assessment of platelet sensitivity to ADP-aggregation was devised. Its reproducibility and the correlations between the values obtained by this method, the optical density (O. D.) method, and the screen filtration pressure (SFP) method were assessed. In summary, this method may be said to have three main points:1. It can be performed without centrifugation, avoiding mechanical stress to platelets, using only 0.8 ml. of blood and inexpensive equipment.2. It may reflect different aspects of platelet function from the O. D. method and the SFP method, despite the positive significant correlations between the values obtained by these three methods.3. It was proved to be highly reproducible and is thought to be useful clinically.By using this method, the effect of sustained isometric exercise by handgripping on platelet aggregability was assessed in coronary sclerotic and cerebral arteriosclerotic patients on placebo and EG-626, a newly synthesized cyclic AMP phosphodiesterase inhibitor. On placebo, an enhancement of platelet sensitivity was observed after isometric exercise in coronary and cerebral arteriosclerotic patients but not in healthy control subjects. The enhancement was prevented by pretreatment of EG-626, administered orally 1.5 hours prior to exercise.

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