Abstract 1531: Altered Brain Fiber Tracts in Heart Failure

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Mary A Woo ◽  
Paul M Macey ◽  
Rajesh Kumar ◽  
Stacy L Serber ◽  
Rebecca Cross ◽  
...  
Keyword(s):  
Heart Failure ◽  
Frontal Cortex ◽  
Diffusion Tensor ◽  
Multiple Comparisons ◽  
Brain Regions ◽  
Imaging Data ◽  
Permutation Testing ◽  
Control Subjects ◽  
Fiber Tracts ◽  
Limbic Regions

Introduction: Heart failure (HF) patients show neuronal brain injury which contributes to cognitive, affective, and autonomic symptoms. However, earlier studies did not consistently report injury within cognitive sites (e.g., frontal cortex) or limbic structures linked to affective and autonomic function. The inconsistent signs of injury in these neuronal structures may result from compromised communication between cognitive and limbic regions from damaged axons. Methods: We studied axon integrity between these regions using tract-based spatial statistics (TBSS; allows study of white matter tracts) in 17 HF (age 54 ± 8 years; 12 males; LVEF 0.28 ± 0.07) and 51 control subjects (age 50 ± 7 years, 29 males). We collected diffusion tensor imaging data using a 3T MRI scanner, from which we calculated fractional anisotropy (FA), an index of axonal integrity. Whole-brain FA “maps” for each subject were processed using TBSS, giving estimated axonal tracts co-localized across subjects. FA values throughout the tracts were compared between groups using 2-sample t-tests, controlling for multiple comparisons by permutation testing (form of randomization test). Results: Fiber tracts in HF showed reduced FA values across multiple brain regions (Figure ), including the anterior corona radiata (projecting to and from frontal cortex) and the superior and inferior cingulum bundle (communicating to and from the cingulate, hippocampus and other limbic regions), and cerebellum (dampens blood pressure changes). Discussion: Cognitive and affective symptoms in HF patients may arise from a combination of damaged structural areas and poor communication between brain regions. Regions of reduced fiber tract integrity (lower FA) in 17 HF versus 51 control subjects indicated in white ( p < 0.05, false discovery rate correction for multiple comparisons). Background image is a reference anatomical scan, with detected fiber tracts as found with TBSS in black. Orientation: images left of image is left of person; locations relative to standard reference (anterior commusure is origin): from left to right, 48 mm anterior, 7 mm left, 39 mm posterior.

scholarly journals A Computational Network Control Theory Analysis of Depression Symptoms

2018 ◽  
Vol 1 ◽  
Author(s):  
Yoed N. Kenett ◽  
Roger E. Beaty ◽  
John D. Medaglia
Keyword(s):  
Control Theory ◽  
Diffusion Tensor ◽  
Brain Regions ◽  
Brain Network ◽  
Network Control ◽  
Depression Symptoms ◽  
Theory Approach ◽  
Imaging Data ◽  
The Brain ◽  
Subclinical Depression

AbstractRumination and impaired inhibition are considered core characteristics of depression. However, the neurocognitive mechanisms that contribute to these atypical cognitive processes remain unclear. To address this question, we apply a computational network control theory approach to structural brain imaging data acquired via diffusion tensor imaging in a large sample of participants, to examine how network control theory relates to individual differences in subclinical depression. Recent application of this theory at the neural level is built on a model of brain dynamics, which mathematically models patterns of inter-region activity propagated along the structure of an underlying network. The strength of this approach is its ability to characterize the potential role of each brain region in regulating whole-brain network function based on its anatomical fingerprint and a simplified model of node dynamics. We find that subclinical depression is negatively related to higher integration abilities in the right anterior insula, replicating and extending previous studies implicating atypical switching between the default mode and Executive Control Networks in depression. We also find that subclinical depression is related to the ability to “drive” the brain system into easy to reach neural states in several brain regions, including the bilateral lingual gyrus and lateral occipital gyrus. These findings highlight brain regions less known in their role in depression, and clarify their roles in driving the brain into different neural states related to depression symptoms.

scholarly journals Integrative Structural Brain Network Analysis In Diffusion Tensor Imaging

2017 ◽  
Author(s):  
Moo K. Chung ◽  
Jamie L. Hanson ◽  
Nagesh Adluru ◽  
Andrew L. Alexander ◽  
Richard J. Davidson ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
Diffusion Tensor ◽  
Structural Connectivity ◽  
Brain Regions ◽  
Brain Network ◽  
Node Degree ◽  
Fiber Tracts ◽  
White Matter Fiber Tracts ◽  
Structural Brain Network ◽  
Structural Networks

AbstractIn diffusion tensor imaging, structural connectivity between brain regions is often measured by the number of white matter fiber tracts connecting them. Other features such as the length of tracts or fractional anisotropy (FA) are also used in measuring the strength of connectivity. In this study, we investigated the effects of incorporating the number of tracts, the tract length and FA-values into the connectivity model. Using various node-degree based graph theory features, the three connectivity models are compared. The methods are applied in characterizing structural networks between normal controls and maltreated children, who experienced maltreatment while living in post-institutional settings before being adopted by families in the US.

Diffusion Tensor Imaging and Fiber Tractography

2009 ◽  
pp. 229-246
Author(s):  
Evanthia E. Tripoliti ◽  
Dimitrios I. Fotiadis ◽  
Konstantia Veliou
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Diffusion Tensor ◽  
Brain Regions ◽  
Cerebral White Matter ◽  
Tissue Microstructure ◽  
Diffusion Weighted Images ◽  
Fiber Tracts ◽  
Diffusion Weighted ◽  
Magnetic Resonance Imaging Mri

Diffusion Tensor Imaging (DTI) is a magnetic resonance imaging (MRI) modality which can significantly improve our understanding of the brain structures and neural connectivity. DTI measures are thought to be representative of brain tissue microstructure and are particularly useful for examining organized brain regions, such as white matter tract areas. DTI measures the water diffusion tensor using diffusion weighted pulse sequences which are sensitive to microscopic random water motion. The resulting diffusion weighted images (DWI) display and allow quantification of how water diffuses along axes or diffusion encoding directions. This can help to measure and quantify the tissue’s orientation and structure, making it an ideal tool for examining cerebral white matter and neural fiber tracts. In this chapter the authors discuss the theoretical aspects of DTI, the information that can be extracted from DTI data, and the use of the extracted information for the reconstruction of fiber tracts and the diagnosis of a disease. In addition, a review of known fiber tracking algorithms is presented.

scholarly journals Cortical atrophy and transcallosal diaschisis following isolated subcortical stroke

2019 ◽  
Vol 40 (3) ◽  
pp. 611-621 ◽  
Author(s):  
Bastian Cheng ◽  
Philipp Dietzmann ◽  
Robert Schulz ◽  
Marlene Boenstrup ◽  
Lutz Krawinkel ◽  
...  
Keyword(s):  
White Matter ◽  
Cortical Thickness ◽  
Diffusion Tensor ◽  
Brain Regions ◽  
White Matter Integrity ◽  
Cortical Atrophy ◽  
Fiber Tractography ◽  
Stroke Patients ◽  
Fiber Tracts ◽  
One Year

Following acute ischemic stroke, isolated subcortical lesions induce gray matter atrophy in anatomically connected, yet distant cortical brain regions. We expand on previous studies by analyzing cortical thinning in contralesional, homologous regions indirectly linked to primary stroke lesions via ipsilesional cortical areas. For this purpose, stroke patients were serially studied by magnetic resonance imaging (diffusion tensor imaging and high-resolution anatomical imaging) in the acute (days 3–5) and late chronic stage one year after stroke. We analyzed changes of gray and white matter integrity in 18 stroke patients (median age 68 years) with subcortical stroke. We applied probabilistic fiber tractography to identify brain regions connected to stroke lesions and contralesional homologous areas. Cortical thickness was quantified by semi-automatic measurements, and fractional anisotropy was analyzed. One year after stroke, significant decrease of cortical thickness was detected in areas connected to ischemic lesions (mean −0.15 mm; 95% CI −0.23 to −0.07 mm) as well as homologous contralateral brain regions (mean −0.13 mm; 95% CI −0.07 to −0.19 mm). We detected reduced white matter integrity of inter- and intrahemispheric fiber tracts. There were no significant associations with clinical recovery. Our results indicate that impact of subcortical lesions extends to homologous brain areas via transcallosal diaschisis.

STRUCTURAL BRAIN NETWORK ABNORMALITIES IN SUBJECTS WITH INTERNET ADDICTION

2017 ◽  
Vol 17 (07) ◽  
pp. 1740031 ◽  
Author(s):  
MIN-HEE LEE ◽  
AREUM MIN ◽  
YOON HO HWANG ◽  
DONG YOUN KIM ◽  
BONG SOO HAN ◽  
...  
Keyword(s):  
Internet Addiction ◽  
Diffusion Tensor ◽  
Brain Connectivity ◽  
Brain Regions ◽  
Brain Network ◽  
Imaging Data ◽  
Structural Brain Network ◽  
Global And Local ◽  
The Impact ◽  
Structural Brain

Although problematic overuse of internet has increased, psychopathological characteristics and neurobiological mechanisms for internet addiction (IA) remain poorly understood. Therefore, it is necessary to investigate the impact of IA on the brain. The present study included 17 subjects with IA and 20 healthy subjects. We constructed the structural brain network from diffusion tensor imaging data and investigated alteration of structural connections in subjects with IA using the network analysis on the global and local levels. The subjects with IA showed increase of regional efficiency (RE) in bilateral orbitofrontal cortex (OFC) and decrease in right middle cingulate and middle temporal gyri ([Formula: see text]), whereas the global properties did not show significant changes. Young’s internet addiction test (IAT) scores and RE in left OFC showed positive correlation, and average time spent on internet per day was positively correlated with the RE in right OFC. This is the first study examining alterations of the structural brain connectivity in IA. We found that subjects with IA showed alterations of RE in some brain regions and RE was positively associated with the severity of IA and average time spent on internet per day. Therefore, RE may be a good property for IA assessment.

scholarly journals Diffusion tensor imaging tensor shape analysis for assessment of regional white matter differences

2017 ◽  
Vol 30 (4) ◽  
pp. 324-329 ◽  
Author(s):  
Dana M Middleton ◽  
Jonathan Y Li ◽  
Hui J Lee ◽  
Steven Chen ◽  
Patricia I Dickson ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Imaging System ◽  
Diffusion Tensor ◽  
Weighted Average ◽  
Internal Capsule ◽  
Brain Regions ◽  
Magnetic Resonance Imaging System ◽  
Imaging Data ◽  
Centrum Semiovale

Purpose The purpose of this study was to investigate a novel tensor shape plot analysis technique of diffusion tensor imaging data as a means to assess microstructural differences in brain tissue. We hypothesized that this technique could distinguish white matter regions with different microstructural compositions. Methods Three normal canines were euthanized at seven weeks old. Their brains were imaged using identical diffusion tensor imaging protocols on a 7T small-animal magnetic resonance imaging system. We examined two white matter regions, the internal capsule and the centrum semiovale, each subdivided into an anterior and posterior region. We placed 100 regions of interest in each of the four brain regions. Eigenvalues for each region of interest triangulated onto tensor shape plots as the weighted average of three shape metrics at the plot's vertices: CS, CL, and CP. Results The distribution of data on the plots for the internal capsule differed markedly from the centrum semiovale data, thus confirming our hypothesis. Furthermore, data for the internal capsule were distributed in a relatively tight cluster, possibly reflecting the compact and parallel nature of its fibers, while data for the centrum semiovale were more widely distributed, consistent with the less compact and often crossing pattern of its fibers. This indicates that the tensor shape plot technique can depict data in similar regions as being alike. Conclusion Tensor shape plots successfully depicted differences in tissue microstructure and reflected the microstructure of individual brain regions. This proof of principle study suggests that if our findings are reproduced in larger samples, including abnormal white matter states, the technique may be useful in assessment of white matter diseases.

Resection of malignant brain tumors in eloquent cortical areas: a new multimodal approach combining 5-aminolevulinic acid and intraoperative monitoring

2010 ◽  
Vol 113 (2) ◽  
pp. 352-357 ◽  
Author(s):  
Guenther C. Feigl ◽  
Rainer Ritz ◽  
Mario Moraes ◽  
Jan Klein ◽  
Kristofer Ramina ◽  
...  
Keyword(s):  
Brain Tumors ◽  
Intraoperative Monitoring ◽  
Aminolevulinic Acid ◽  
Diffusion Tensor ◽  
Imaging Data ◽  
Eloquent Areas ◽  
Cortical Areas ◽  
Malignant Brain Tumors ◽  
Fiber Tracts ◽  
Functional Areas

Object Several studies have revealed that the gross-total resection (GTR) of malignant brain tumors has a significant influence on patient survival. Frequently, however, GTR cannot be achieved because the borders between healthy brain and diseased tissue are blurred in the infiltration zones of malignant brain tumors. Especially in eloquent cortical areas, resection is frequently stopped before total removal is achieved to avoid causing neurological deficits. Interestingly, 5-aminolevulinic acid (5-ALA) has been shown to help visualize tumor tissue intraoperatively and, thus, can significantly improve the possibility of achieving GTR of primary malignant brain tumors. The aim of this study was to go one step further and evaluate the utility and limitations of fluorescence-guided resections of primary malignant brain tumors in eloquent cortical areas in combination with intraoperative monitoring based on multimodal functional imaging data. Methods Eighteen patients with primary malignant brain tumors in eloquent areas were included in this prospective study. Preoperative neuroradiological examinations included MR imaging with magnetization-prepared rapid gradient echo (MPRAGE), functional MR, and diffusion tensor imaging sequences to visualize functional areas and fiber tracts. Imaging data were analyzed offline, loaded into a neuronavigational system, and used intraoperatively during resections. All patients received 5-ALA 6 hours before surgery. Fluorescence-guided tumor resections were combined with intraoperative monitoring and cortical as well as subcortical stimulation to localize functional areas and fiber tracts during surgery. Results Twenty-five procedures were performed in 18 consecutive patients. In 24% of all surgeries, resection was stopped because a functional area or cortical tract was identified in the resection area or because motor evoked potential amplitudes were reduced in an area where fluorescent tumor cells were still seen intraoperatively. Grosstotal resection could be achieved in 16 (64%) of the surgeries with preservation of all functional areas and fiber tracts. In 2 patients presurgical hemiparesis became accentuated postoperatively, and 1 of these patients also suffered from a new homonymous hemianopia following a second resection. Conclusions The authors' first results show that tumor resections with 5-ALA in combination with intraoperative cortical stimulation have the advantages of both methods and, thus, provide additional safety for the neurosurgeon during resections of primary malignant brain tumors in eloquent areas. Nonetheless, more cases and additional studies are necessary to further prove the advantages of this multimodal strategy.

scholarly journals Ultra-high-field imaging reveals increased whole brain connectivity underpins cognitive strategies that attenuate pain

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Enrico Schulz ◽  
Anne Stankewitz ◽  
Anderson M Winkler ◽  
Stephanie Irving ◽  
Viktor Witkovský ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Diffusion Tensor ◽  
Brain Connectivity ◽  
Cognitive Strategies ◽  
Brain Regions ◽  
Imaging Data ◽  
Cold Pain ◽  
Whole Brain ◽  
Safe Place ◽  
Strength Change

We investigated how the attenuation of pain with cognitive interventions affects brain connectivity using neuroimaging and a whole brain novel analysis approach. While receiving tonic cold pain, 20 healthy participants performed three different pain attenuation strategies during simultaneous collection of functional imaging data at seven tesla. Participants were asked to rate their pain after each trial. We related the trial-by-trial variability of the attenuation performance to the trial-by-trial functional connectivity strength change of brain data. Across all conditions, we found that a higher performance of pain attenuation was predominantly associated with higher functional connectivity. Of note, we observed an association between low pain and high connectivity for regions that belong to brain regions long associated with pain processing, the insular and cingulate cortices. For one of the cognitive strategies (safe place), the performance of pain attenuation was explained by diffusion tensor imaging metrics of increased white matter integrity.

scholarly journals Contribution of Neuro-Imaging for Prediction of Functional Recovery after Ischemic Stroke

2017 ◽  
Vol 44 (5-6) ◽  
pp. 266-276 ◽  
Author(s):  
Wolf-Dieter Heiss
Keyword(s):  
Ischemic Stroke ◽  
Diffusion Tensor ◽  
Recovery Process ◽  
Therapeutic Effects ◽  
Collateral Flow ◽  
Imaging Data ◽  
Ischemic Lesion ◽  
Therapeutic Consequences ◽  
Fiber Tracts ◽  
Improved Performance

Prediction measures of recovery and outcome after stroke perform with only modest levels of accuracy if based only on clinical data. Prediction scores can be improved by including morphologic imaging data, where size, location, and development of the ischemic lesion is best documented by magnetic resonance imaging. In addition to the primary lesion, the involvement of fiber tracts contributes to prognosis, and consequently the use of diffusion tensor imaging (DTI) to assess primary and secondary pathways improves the prediction of outcome and of therapeutic effects. The recovery of ischemic tissue and the progression of damage are dependent on the quality of blood supply. Therefore, the status of the supplying arteries and of the collateral flow is not only crucial for determining eligibility for acute interventions, but also has an impact on the potential to integrate areas surrounding the lesion that are not typically part of a functional network into the recovery process. The changes in these functional networks after a localized lesion are assessed by functional imaging methods, which additionally show altered pathways and activated secondary centers related to residual functions and demonstrate changes in activation patterns within these networks with improved performance. These strategies in some instances record activation in secondary centers of a network, for example, also in homolog contralateral areas, which might be inhibitory to the recovery of primary centers. Such findings might have therapeutic consequences, for example, image-guided inhibitory stimulation of these areas. In the future, a combination of morphological imaging including DTI of fiber tracts and activation studies during specific tasks might yield the best information on residual function, reserve capacity, and prospects for recovery after ischemic stroke.

Tissue Plasminogen Activator Release in Chronic Venous Hypertension due to Heart Failure

1992 ◽  
Vol 68 (03) ◽  
pp. 321-324 ◽  
Author(s):  
Irena Keber ◽  
Dušan Keber ◽  
Mojca Stegnar ◽  
Nina Vene
Keyword(s):  
Heart Failure ◽  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Venous Pressure ◽  
Venous Hypertension ◽  
Plasminogen Activator Inhibitor 1 ◽  
Control Subjects ◽  
Tissue Plasminogen ◽  
Pai 1

SummaryIn order to study the effects of chronic venous hypertension due to heart failure on blood fibrinolytic activity, tissue plasminogen activator (t-PA) antigen, plasminogen activator inhibitor 1 (PAI-1) antigen, t-PA activity and PAI activity were measured before and after venous occlusion of the arm for 20 min in 15 patients with right-sided heart failure, 15 patients with left-sided heart failure, and 30 control healthy subjects. Central venous pressure, measured by observing the jugular veins, was above 15 cm of the blood column in all patients with right-sided heart failure, and normal (below 8 cm) in all patients with left-sided heart failure and control subjects. There was no difference in the basal concentrations of t-PA (11.0, 10.2 and 10.8 ng/ml; all values medians) and PAI-1 antigens and their activities between right and left-sided heart failure and the control subjects. After the occlusion, t-PA antigen increased significantly less in right-sided heart failure (28.6 ng/ml) than in left-sided heart failure and the control subjects (54.5 and 45.9 ng/ml, respectively). It was concluded that the poor increase in fibrinolytic activity that had already been reported in patients with heart failure, was due to low t-PA release during occlusion and not to a high basal PAI level. It was limited to the patients with right-sided heart failure and was probably the consequence of chronic systemic venous hypertension.

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