Brain Tissue Biomechanics and Pathobiology of Blast-Induced Traumatic Brain Injury PDF Download

Author: Sowmya N. Sundaresh
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Together, this illustrated the ability of these two enzymes to regulate the response to exposure of bTBI-induced pathogenic forms of tau. This study indicates the potential of targeting PP2A activity as a viable strategy for therapeutic intervention. In conclusion, this research expands our understanding of the complexity of brain tissue injury mechanics to inform computational models of TBI, illustrates the deleterious effect of pathogenic forms of tau induced by blast injury on cognitive function, and presents a potential target mechanism for the investigation of therapeutic strategies.

Author: Soroush Assari
Publisher:
ISBN:
Category :
Languages : en
Pages : 91

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The focus of this dissertation was the biomechanics of blast-induced traumatic brain injury (bTBI). This study had three specific aims. One of the specific aims was to investigate the thoracic mechanism of bTBI by characterizing the cerebral blood pressure change during local blast exposure to head or chest in a rat model. This model utilized a shock tube to simulate the blast wave. The results showed that there is a blood pressure rise with high amplitude and short duration during both Head-Only and Chest-Only exposure conditions. It was shown that cerebral blood pressure rise was significantly higher in Chest-Only exposure, and resulted in astrocyte reactivation, and infiltration of blood-borne macrophages into the brain. It was concluded that due to chest exposure to a blast wave, high amplitude pressure waves that transfer from thoracic large vessels to cerebrovasculature can lead to blood-brain barrier disruption or perivascular injury and consequently trigger secondary neuronal damage. The second and third aims were related to the viscoelasticity and heterogeneity of brain tissue respectively for blast rate loading conditions. For the second specific aim, a novel test method was developed to apply shear deformation to samples of brain tissue with strain rates in the range of 300 to 1000 s-1. The results of shear tests on cylindrical samples of bovine brain showed that the instantaneous shear modulus (about 6 kPa) increased about 3 times compared to the values reported in the literature. For the third specific aim, local viscoelastic behavior of rat brain was characterized using a micro-indentation setup with the spatial resolution of 350 mm. The results of micro-indentation tests showed that the heterogeneity of brain tissue was more pronounced in long-term shear moduli. Moreover, the inner anatomical regions were generally more compliant than the outer regions and the gray matter generally exhibited a stiffer response than the white matter. The results of this study can enhance the prediction of brain injury in finite element models of TBI in general and models of bTBI in particular. These results contribute to development of more biofidelic models that can determine the extent and severity of injury in blast loadings. Such predictions are essential for designing better injury mitigation devices for soldiers and also for improving neurosurgical procedures among other applications.

Author: Daniel Laskowitz
Publisher: CRC Press
ISBN: 1498766579
Category : Medical
Languages : en
Pages : 388

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Traumatic brain injury (TBI) remains a significant source of death and permanent disability, contributing to nearly one-third of all injury related deaths in the United States and exacting a profound personal and economic toll. Despite the increased resources that have recently been brought to bear to improve our understanding of TBI, the developme

Author: Atacan Yucesoy
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 0

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Blast-induced traumatic brain injury (bTBI) is a widespread pathology and one of the leading causes of mortality and morbidity among military personnel. Exploring the mechanics of brain tissue is critical to predicting intracranial brain deformation and injuries resulting from severe blast loading. The research reported in this dissertation is aimed at investigating three aspects of bTBI research: (1) to build a numerical method with the ability to capture the complex deformation induced by blast loading of the human brain, and (2) to investigate the effects of morphological and volumetric differences on human brain dynamics under blast loading, and (3) to determine residual stresses resulting from cortical folding during brain growth via simulations of volumetric tissue expansion.Although shear stress, cavitation, and severe pressure gradients are suspected to induce brain injury, the details of the ensuing neuropathological consequences are largely unknown. Recent advances in computational tools allow exploring neuropathological damages occurring in human brain tissue resulting from exogenous mechanical forces that are present during bTBI. In this computational study, the numerical model is developed by using explicit nonlinear dynamic code LS-Dyna using Multi-Material Arbitrary Lagrange Eulerian formulation.In addition, this report includes a finite element analysis implemented with ABAQUS to predict the emerging morphological patterns and residual stresses of a developing brain as a result of cortical folding. One aim of the systematic approach presented in this research is to develop computational procedures that can assist in obtaining a prognosis and choosing adequate neurosurgical procedures before a physical intervention is needed.

Author: Firas H. Kobeissy
Publisher: CRC Press
ISBN: 1466565993
Category : Medical
Languages : en
Pages : 718

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Book Description
With the contribution from more than one hundred CNS neurotrauma experts, this book provides a comprehensive and up-to-date account on the latest developments in the area of neurotrauma including biomarker studies, experimental models, diagnostic methods, and neurotherapeutic intervention strategies in brain injury research. It discusses neurotrauma mechanisms, biomarker discovery, and neurocognitive and neurobehavioral deficits. Also included are medical interventions and recent neurotherapeutics used in the area of brain injury that have been translated to the area of rehabilitation research. In addition, a section is devoted to models of milder CNS injury, including sports injuries.

Author: Joseph Augustus Kerwin
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 193

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Book Description
Traumatic brain injury (TBI) is an endemic problem in both civilian and military populations. In the United States, the incidence of civilian TBI is over a million cases annually, with some years (2014) reaching over 2.5 million TBI-related emergency department visits. In recent decades, a new category of TBI has emerged - primary blast loading or otherwise known as, blast-induced traumatic brain injuries (bTBI). bTBI has become the "signature wound'' of the Iraq (Operation Iraqi Freedom [OIF]) and Afghanistan (Operation Enduring Freedom [OEF]) conflicts as it has accounted for nearly 70% of all of the injuries to military service members. Until recently, bTBI has been almost entirely isolated to conflict regions. In August 2020, a catastrophic detonation accidentally occurred in Beirut, Lebanon that instantly affected over 300,000 people.The high prevalence of TBIs in both the civilian and military communities has led to a significant societal burden and is one of the leading public health problems we face today. The treatment and prevention of TBIs has become a major focus within the past decade for all of the United States military branches. The increased awareness of TBI/bTBI has brought about great understanding in both the medical and research fields of neurology; however, it has also shed light on just how little we previously understood about this injury. TBI is a multifaceted problem that encompasses multiple length scales, complex anatomical geometries, and nonlinear biological responses and has various time-scales depending on the severity of the injury. The objective of this research is to investigate the potential injury-causing mechanisms present during the biomechanical loading of TBI events. More specifically, it focuses on the parallels between TBI and bTBI. The bTBI community is actively debating several potential damage-causing primary mechanisms: direct cranial transmission, skull flexure, skull orifices, and thoracic surge. To this end, a brain-tissue phantom was created to investigate its response to different biomechanical loading scenarios. The phantom was fabricated into a three-dimensional extruded ellipsoid geometry made out of Polyacrylamide gelatin that incorporated gyri-sulci interaction. Additionally, the dominant length scales of the sulci, gyri, gray matter thickness, and overall brain dimensions were incorporated into the gelatin brain phantom. The phantom was assembled into a polylactic acid 3D-printed skull, surrounded with deionized water, and enclosed between two optical windows to create a human head surrogate.In this work, the response of the human-head surrogate was evaluated under two biomechanical loading conditions: blunt-force impacts and blast loading. A custom-built drop-tower apparatus was used for the blunt-force impacts and a state-of-the-art blast chamber was employed to characterize the human-head surrogate under blast conditions. These two experimental apparatuses aided in the investigation into the potential damage-causing mechanisms associated with TBI/bTBI. A noninvasive high-speed imaging system was used to capture the surrogate-head response from each biomechanical loading condition. Finally, digital image processing techniques were used to evaluate the kinematic motion of the entire surrogate head, but more importantly the direct response of the gelatin-brain phantom itself.

Author: Nicholas Stephen Race
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Author: Mahdi Sotudeh Chafi
Publisher:
ISBN:
Category : Brain
Languages : en
Pages : 408

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Author: Nikolai Gorbunov
Publisher: BoD – Books on Demand
ISBN: 1789231167
Category : Medical
Languages : en
Pages : 244

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Book Description
Traumatic brain injury (TBI) syndrome has emerged as a serious health concern worldwide due to the severity of outcomes and growing socioeconomic impacts of the diseases, e.g., high cost of long-term medical care and loss of quality of life. This book focuses on the TBI pathobiology as well as on the recent developments in advanced diagnostics and acute management. The presented topics encompass personal experience and visions of the chapter contributors as well as an extensive analysis of the TBI literature. The book is addressed to a broad audience of readers from students to practicing clinicians.

Author: Institute of Medicine
Publisher: National Academies Press
ISBN: 0309124085
Category : Medical
Languages : en
Pages : 396

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Book Description
The seventh in a series of congressionally mandated reports on Gulf War veterans health, this volume evaluates traumatic brain injury (TBI) and its association with long-term health affects. That many returning veterans have TBI will likely mean long-term challenges for them and their family members. Further, many veterans will have undiagnosed brain injury because not all TBIs have immediately recognized effects or are easily diagnosed with neuroimaging techniques. In an effort to detail the long term consequences of TBI, the committee read and evaluated some 1,900 studies that made up its literature base, and it developed criteria for inclusion of studies to inform its findings. It is clear that brain injury, whether penetrating or closed, has serious consequences. The committee sought to detail those consequences as clearly as possible and to provide a scientific framework to assist veterans as they return home.