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Norris C, Murphy SF, Talty CE, VandeVord PJ. Spatial Intracranial Pressure Fields Driven by Blast Overpressure in Rats. Ann Biomed Eng 2024:10.1007/s10439-024-03544-7. [PMID: 38851659 DOI: 10.1007/s10439-024-03544-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 05/08/2024] [Indexed: 06/10/2024]
Abstract
Free-field blast exposure imparts a complex, dynamic response within brain tissue that can trigger a cascade of lasting neurological deficits. Full body mechanical and physiological factors are known to influence the body's adaptation to this seemingly instantaneous insult, making it difficult to accurately pinpoint the brain injury mechanisms. This study examined the intracranial pressure (ICP) profile characteristics in a rat model as a function of blast overpressure magnitude and brain location. Metrics such as peak rate of change of pressure, peak pressure, rise time, and ICP frequency response were found to vary spatially throughout the brain, independent of blast magnitude, emphasizing unique spatial pressure fields as a primary biomechanical component to blast injury. This work discusses the ICP characteristics and considerations for finite element models, in vitro models, and translational in vivo models to improve understanding of biomechanics during primary blast exposure.
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Affiliation(s)
- Carly Norris
- School of Biomedical Engineering and Sciences, Virginia Tech, Blacksburg, VA, USA
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, USA
| | - Susan F Murphy
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, USA
- Veterans Affairs Medical Center, Salem, VA, USA
| | - Caiti-Erin Talty
- Graduate Program in Translational Biology, Medicine and Health, Virginia Tech, Blacksburg, VA, USA
| | - Pamela J VandeVord
- School of Biomedical Engineering and Sciences, Virginia Tech, Blacksburg, VA, USA.
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, USA.
- Veterans Affairs Medical Center, Salem, VA, USA.
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2
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Spencer RW, Brokaw E, Carr W, Chen ZJ, Garfield BA, Garimella HT, Gharahi H, Iampaglia J, Lalis L, Przekwas A, Skotak M, Xynidis MA, Dominijanni A, Dias G, Danley L, Gupta RK. Fiscal Year 2018 National Defense Authorization Act, Section 734, Weapon Systems Line of Inquiry: Overview and Blast Overpressure Tool-A Module for Human Body Blast Wave Exposure for Safer Weapons Training. Mil Med 2023; 188:536-544. [PMID: 37948275 DOI: 10.1093/milmed/usad225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 04/10/2023] [Accepted: 06/09/2023] [Indexed: 11/12/2023] Open
Abstract
INTRODUCTION Experiences by service members in recent conflicts and training environments illuminate concerns about the possible effects of blast overpressure (BOP) exposure on brain health. Section 734 of the National Defense Authorization Act for Fiscal Year (FY) 2018 (Public Law 115-91) requires that the Secretary of Defense conducts a longitudinal medical study on blast pressure exposure of members of the Armed Forces during combat and training, and the Assistant Secretary of Defense for Health Affairs was assigned responsibility for fulfilling requirements. The study's goal is to improve DoD's understanding of the impact of BOP exposure from weapon systems on service members' brain health and inform policy for risk mitigation, unit readiness, and health care decisions. This article focuses on the activities of the Weapon Systems Line of Inquiry (LOI) and the development of a prototype BOP Tool. MATERIALS AND METHODS The DoD established the Section 734 Workgroup, which developed a program structure with five LOIs. The Weapon Systems LOI coordinated, collated, and analyzed information on BOP resulting from heavy weapons and blast events to inform strategies, and accounted for emerging research on health effects and performance. Ongoing research was leveraged to develop a BOP Tool as a standalone module and for integration into the Range Managers Toolkit. RESULTS The effort identified opportunities for the DoD to improve the clarity of communications about BOP exposure, risk, and safety; establish methods to leverage emerging research; and develop a prototype BOP Tool to predict exposure loads when firing heavy weapons in training. CONCLUSIONS It is recommended that the DoD revises requirements and policy to improve and standardize safety guidance throughout research, development, testing, and evaluation; acquisition; and training. The validated BOP Tool allows users to generate a scenario to predict BOP exposure and allows service members to modify them during planning for safer training.
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Affiliation(s)
| | | | - Walter Carr
- Computational Fluid Dynamics Research Corporation (CFDRC), Huntsville, AL 35806, USA
| | - Zhijian J Chen
- Walter Reed Army Institute of Research (WRAIR), Silver Spring, MD 20910, USA
| | - Bradley A Garfield
- Computational Fluid Dynamics Research Corporation (CFDRC), Huntsville, AL 35806, USA
| | - Harsha T Garimella
- Walter Reed Army Institute of Research (WRAIR), Silver Spring, MD 20910, USA
| | - Hamidreza Gharahi
- Walter Reed Army Institute of Research (WRAIR), Silver Spring, MD 20910, USA
| | - Joseph Iampaglia
- US Army Training Doctrine and Command (TRADOC) Range Safety Team (USA/USMC), Fort Eustis, VA 23604-5748, USA
| | - Lisa Lalis
- The MITRE Corporation, McLean, VA 22102-7539, USA
| | - Andrzej Przekwas
- Walter Reed Army Institute of Research (WRAIR), Silver Spring, MD 20910, USA
| | - Maciej Skotak
- US Army Training Doctrine and Command (TRADOC) Range Safety Team (USA/USMC), Fort Eustis, VA 23604-5748, USA
| | | | | | - George Dias
- The MITRE Corporation, McLean, VA 22102-7539, USA
| | - Lura Danley
- The MITRE Corporation, McLean, VA 22102-7539, USA
| | - Raj K Gupta
- US Army Medical Research and Development Command (USAMRDC), Fort Detrick, MD 21702-5000, USA
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Sours Rhodes C, Sandlain R, Ollinger J, Bryden D, Dittmer T, DeGraba TJ, Teslovich T. Development of the Blast Ordnance and Occupational Exposure Measure for Self-Reported Lifetime Blast Exposures. Mil Med 2023; 188:3336-3342. [PMID: 35855546 DOI: 10.1093/milmed/usac212] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 06/10/2022] [Accepted: 06/30/2022] [Indexed: 11/14/2022] Open
Abstract
INTRODUCTION To address the military gap in the standardized collection of lifetime blast exposures across clinical and research endeavors, researchers at the National Intrepid Center of Excellence (NICoE) completed a quality improvement project that utilized systematic, iterative focus groups that leveraged the input from various stakeholders including subject matter experts, clinical providers, and service members (SMs) to develop a comprehensive, self-report blast exposure inventory that could be completed within 5-10 minutes. This manuscript outlines the process of the development of this inventory. MATERIALS AND METHODS This project included three phases of focus groups that occurred at the NICoE between August 2020 and March 2021 to collect feedback and input from relevant military stakeholders. The study team utilized related assessments available in the literature, together with clinical experience with the NICoE patient population, to inform the development of an initial draft inventory. Phase 1 consisted of blast injury research subject matter experts who had extensive experience researching and providing clinical care to SMs exposed to blast. Phase 2 consisted of NICoE clinicians across numerous clinical specialties. Phase 3 included current active duty patients in the NICoE intensive outpatient program. RESULTS Following completion of the focus groups, a lifetime blast exposure inventory was developed in the form of a single page table including incoming, outgoing, training, and operational exposures and broken down by levels of weapon systems as well as breaching and explosive ordnance disposal exposures. In addition, select questions related to the first and most recent blast exposures and experience as an instructor for explosive ordnance disposal- and breaching-related training were included. CONCLUSIONS Researchers at the NICoE developed a self-report blast exposure inventory through a quality improvement project that included active, ongoing participation and feedback of clinical experts and military SMs. The end result is a brief, single page inventory that can be administered within 5-10 minutes. Although additional research is needed to refine and validate the inventory, the project team believes that the tool begins to address a long-standing gap in the DoD in the standardized collection of lifetime blast exposures.
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Affiliation(s)
- Chandler Sours Rhodes
- National Intrepid Center of Excellence, Walter Reed National Military Medical Center, Bethesda, MD 20889-5649, USA
| | - Rebecca Sandlain
- Contractor in Support of National Intrepid Center of Excellence, Walter Reed National Military Medical Center, Bethesda, MD 20889-5649, USA
| | - John Ollinger
- National Intrepid Center of Excellence, Walter Reed National Military Medical Center, Bethesda, MD 20889-5649, USA
| | | | | | - Thomas J DeGraba
- National Intrepid Center of Excellence, Walter Reed National Military Medical Center, Bethesda, MD 20889-5649, USA
- Department of Neurology, Uniformed Services University of the Health Sciences, Bethesda, MD 20889-5649, USA
| | - Theresa Teslovich
- National Intrepid Center of Excellence, Walter Reed National Military Medical Center, Bethesda, MD 20889-5649, USA
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Rojas-Valverde D, Gómez-Ruano MA, Ibañez SJ, Nikolaidis PT. Editorial: New technologies and statistical models applied to sports and exercise science research: methodological, technical and practical considerations. Front Sports Act Living 2023; 5:1267548. [PMID: 37662114 PMCID: PMC10473824 DOI: 10.3389/fspor.2023.1267548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 08/01/2023] [Indexed: 09/05/2023] Open
Affiliation(s)
- Daniel Rojas-Valverde
- Centro de Investigación y Diagnóstico en Salud y Deporte (CIDISAD-NARS), Escuela Ciencias del Movimiento Humano y Calidad de Vida, Universidad Nacional, Heredia, Costa Rica
- Sport Injury Clinic, Escuela Ciencias del Movimiento Humano y Calidad de Vida, Universidad Nacional, Heredia, Costa Rica
| | - Miguel A. Gómez-Ruano
- Facultad de Ciencias de la Actividad Física y el Deporte, Universidad Politécnica de Madrid, Madrid, Spain
| | - Sergio J. Ibañez
- Grupo de Optimización del Entrenamiento y Rendimiento Deportivo, Universidad de Extremadura, Cáceres, Spain
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Gharahi H, Garimella HT, Chen ZJ, Gupta RK, Przekwas A. Mathematical model of mechanobiology of acute and repeated synaptic injury and systemic biomarker kinetics. Front Cell Neurosci 2023; 17:1007062. [PMID: 36814869 PMCID: PMC9939777 DOI: 10.3389/fncel.2023.1007062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 01/10/2023] [Indexed: 02/09/2023] Open
Abstract
Background Blast induced Traumatic Brain Injury (bTBI) has become a signature casualty of military operations. Recently, military medics observed neurocognitive deficits in servicemen exposed to repeated low level blast (LLB) waves during military heavy weapons training. In spite of significant clinical and preclinical TBI research, current understanding of injury mechanisms and short- and long-term outcomes is limited. Mathematical models of bTBI biomechanics and mechanobiology of sensitive neuro-structures such as synapses may help in better understanding of injury mechanisms and in the development of improved diagnostics and neuroprotective strategies. Methods and results In this work, we formulated a model of a single synaptic structure integrating the dynamics of the synaptic cell adhesion molecules (CAMs) with the deformation mechanics of the synaptic cleft. The model can resolve time scales ranging from milliseconds during the hyperacute phase of mechanical loading to minutes-hours acute/chronic phase of injury progression/repair. The model was used to simulate the synaptic injury responses caused by repeated blast loads. Conclusion Our simulations demonstrated the importance of the number of exposures compared to the duration of recovery period between repeated loads on the synaptic injury responses. The paper recognizes current limitations of the model and identifies potential improvements.
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Affiliation(s)
- Hamidreza Gharahi
- Biomedical and Data Sciences Division, CFD Research Corporation, Huntsville, AL, United States,Hamidreza Gharahi,
| | - Harsha T. Garimella
- Biomedical and Data Sciences Division, CFD Research Corporation, Huntsville, AL, United States
| | - Zhijian J. Chen
- Biomedical and Data Sciences Division, CFD Research Corporation, Huntsville, AL, United States
| | - Raj K. Gupta
- Department of Defense Blast Injury Research Program Coordinating Office, U.S. Army Medical Research and Development Command, Fort Detrick, MD, United States
| | - Andrzej Przekwas
- Biomedical and Data Sciences Division, CFD Research Corporation, Huntsville, AL, United States,*Correspondence: Andrzej Przekwas,
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Gu L, Zhou M, Wei T, Yang H, Zhou Y. Extreme Membrane Tensile Loads Induce Half-Activation of the Thermosensitive TRPV1 Channel. J Phys Chem Lett 2022; 13:6306-6310. [PMID: 35792613 DOI: 10.1021/acs.jpclett.2c01206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Transient receptor potential (TRP) channels are sensors for a wide range of cellular and environmental signals, but elucidating how these channels convert a wide range of physical and chemical stimuli into channel opening is essential to understanding their normal function. Here, half-activation of thermosensitive TRPV1 channel under extreme membrane stretching from blast loads was provided by molecular dynamics simulations. The results show that such extreme membrane stretch loading will only lead to half-activation of the TRPV1 channel: that is, the upper gate is open for high-speed stretching (>15m/s), but the lower gate is still closed. The corresponding activation threshold also depends on both the tensile speed and the area strain. This means that the direct mechanical gating of TRP channels in one step is unlikely to occur.
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Affiliation(s)
- Lingzhi Gu
- Institute of Chemical Materials, China Academy of Engineering and Physics, Mianyang 621900, China
| | - Mi Zhou
- Institute of Chemical Materials, China Academy of Engineering and Physics, Mianyang 621900, China
| | - Tong Wei
- Institute of Chemical Materials, China Academy of Engineering and Physics, Mianyang 621900, China
| | - Hong Yang
- Institute of Chemical Materials, China Academy of Engineering and Physics, Mianyang 621900, China
| | - Yang Zhou
- Institute of Chemical Materials, China Academy of Engineering and Physics, Mianyang 621900, China
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Du Z, Li Z, Wang P, Wang X, Zhang J, Zhuang Z, Liu Z. Revealing the Effect of Skull Deformation on Intracranial Pressure Variation During the Direct Interaction Between Blast Wave and Surrogate Head. Ann Biomed Eng 2022; 50:1038-1052. [PMID: 35668281 DOI: 10.1007/s10439-022-02982-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 05/13/2022] [Indexed: 11/01/2022]
Abstract
Intracranial pressure (ICP) during the interaction between blast wave and the head is a crucial evaluation criterion for blast-induced traumatic brain injury (bTBI). ICP variation is mainly induced by the blast wave transmission and skull deformation. However, how the skull deformation influences the ICP remains unclear, which is meaningful for mitigating bTBI. In this study, both experimental and numerical models are developed to elucidate the effect of skull deformation on ICP variation. Firstly, we performed the shock tube experiment of the high-fidelity surrogate head to measure the ICP, the blast overpressure, and the skull surface strain of specific positions. The results show that the ICP profiles of all measured points show oscillations with positive and negative change, and the variation is consistent with the skull surface strain. Further numerical analysis reveals that when the blast wave reaches the measured point, the peak overpressure transmits directly through the skull to the brain, forming the local positive ICP peak, and the impulse induces the local inward deformation of the skull. As the peak overpressure passes through, the blast impulse impacts the nearby skull supported by the soft and incompressible brain tissue and extrudes the skull outward in the initial position. The inward and outward skull deformation leads to the oscillation of ICP. These numerical analyses agree with experimental results, which explain the appearance of negative and positive ICP peaks and the synchronization of negative ICP with surface strain. The study has implications for medical injury diagnosis and protective equipment design.
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Affiliation(s)
- Zhibo Du
- School of Aerospace Engineering, Tsinghua University, Beijing, 100084, P.R. China
| | - Zhijie Li
- School of Aerospace Engineering, Tsinghua University, Beijing, 100084, P.R. China
| | - Peng Wang
- School of Aerospace Engineering, Tsinghua University, Beijing, 100084, P.R. China
| | - Xinghao Wang
- School of Aerospace Engineering, Tsinghua University, Beijing, 100084, P.R. China
| | - Jiarui Zhang
- School of Aerospace Engineering, Tsinghua University, Beijing, 100084, P.R. China
| | - Zhuo Zhuang
- School of Aerospace Engineering, Tsinghua University, Beijing, 100084, P.R. China
| | - Zhanli Liu
- School of Aerospace Engineering, Tsinghua University, Beijing, 100084, P.R. China.
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8
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Hasan F, Al Mahmud KAH, Khan MI, Kang W, Adnan A. Effect of random fiber networks on bubble growth in gelatin hydrogels. SOFT MATTER 2021; 17:9293-9314. [PMID: 34647568 DOI: 10.1039/d1sm00587a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In hydrodynamics, the event of dynamic bubble growth in a pure liquid under tensile pressure is known as cavitation. The same event can also be observed in soft materials (e.g., elastomers and hydrogels). However, for soft materials, bubble/cavity growth is either defined as cavitation if the bubble growth is elastic and reversible or as fracture if the cavity growth is by material failure and irreversible. In any way, bubble growth can cause damage to soft materials (e.g., tissue) by inducing high strain and strain-rate deformation. Additionally, a high-strength pressure wave is generated upon the collapse of the bubble. Therefore, it is crucial to identify the critical condition of spontaneous bubble growth in soft materials. Experimental and theoretical observations have agreed that the onset of bubble growth in soft materials requires higher tensile pressure than pure water. The extra tensile pressure is required since the cavitating bubble needs to overcome the elastic and surface energy in soft materials. In this manuscript, we developed two models to study and quantify the extra tensile pressure for different gelatin concentrations. Both the models are then compared with the existing cavitation onset criteria of rubber-like materials. Validation is done with the experimental results of threshold tensile pressure for different gelatin concentrations. Both models can moderately predict the extra tensile pressure within the intermediate range of gelatin concentrations (3-7% [w/v]). For low concentration (∼1%), the network's non-affinity plays a significant role and must be incorporated. On the other hand, for higher concentrations (∼10%), the entropic deformation dominates, and the strain energy formulation is not adequate.
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Affiliation(s)
- Fuad Hasan
- Department of Mechanical and Aerospace Engineering, The University of Texas at Arlington, USA.
- Woolf Hall, Room 315C, Arlington, TX 76019, USA
| | - K A H Al Mahmud
- Department of Mechanical and Aerospace Engineering, The University of Texas at Arlington, USA.
- Woolf Hall, Room 315C, Arlington, TX 76019, USA
| | - Md Ishak Khan
- Department of Mechanical and Aerospace Engineering, The University of Texas at Arlington, USA.
- Woolf Hall, Room 315C, Arlington, TX 76019, USA
| | - Wonmo Kang
- School for Engineering of Matter, Transport and Energy, Arizona State University, USA
| | - Ashfaq Adnan
- Department of Mechanical and Aerospace Engineering, The University of Texas at Arlington, USA.
- Woolf Hall, Room 315C, Arlington, TX 76019, USA
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Burkle FM, Hadley KS, Ridge LL, Herman JK, Kobeissy FH. Delayed-Onset Neuropathological Complications From a Foramen Magnum and Occipital Crest Focused Traumatic Brain Injury of the Vietnam War and Other Conflicts: Part I, Case Report. Mil Med 2021; 187:e921-e925. [PMID: 34632519 DOI: 10.1093/milmed/usab371] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 04/23/2021] [Accepted: 09/17/2021] [Indexed: 11/14/2022] Open
Abstract
INTRODUCTION The diagnosis of traumatic brain injuries is typically based on hemispheric blasts resulting in degrees of unconsciousness and associated cerebral injuries. This case report describes a Vietnam War era setting in which a traumatic blast wave struck the posterior cranium in the region of the foramen magnum, occipital crest, and other skull openings (orbit, oronasal, and ear) and the unique secondary clinical signs and symptoms experienced over time. MATERIALS AND METHODS This case report describes secondary delayed-onset clinical signs and symptoms consistent with progressive decades-long physical and functional complications. The traumatic blast resulted in brief unconsciousness, decreased vision in left eye, confusion, right sided hemotympanum, deafness, severe tinnitus, severe nasopharynx pain and difficulty swallowing, pain in right posterior and occipital area of the head, and loss of dental amalgams. Subsequent exams revealed progressive hyperacusis, sea sickness, dysdiadochokinesis, diagnosis of 9th and 10th cranial nerve traumatic schwannomas, hyperdense changes to the frontal lobe white matter, progressive tinnitus, chronic vertigo, right-sided high-frequency hearing loss, progressive oculo-gyric crisis of Tumarkin-like seizures, left-sided chronic vitreous hemorrhage, and diminished right hemisphere performance of the brain based on neurophysiological assessment. No post-traumatic stress, depression, or other emotional or psychiatric difficulties were claimed. CONCLUSION This case report, unique to the English language scientific literature, discusses in detail the secondary signs and symptoms of a foramen magnum and occipital crest focused-associated blast injury.
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Affiliation(s)
- Frederick M Burkle
- Harvard Humanitarian Initiative, Harvard University, and T.H. Chan School of Public Health, Cambridge, MA 02138, USA.,Global Scholar, Woodrow Wilson International Center for Scholars, Washington, DC 20004-3027, USA
| | - Kevin S Hadley
- Practice of Otolaryngology, Otology & Neurotology, President, Hawaii Ear Clinic, Inc, Aiea, HI 96701, USA
| | - Leah L Ridge
- Practice of Neurology, Ohana Neurology, Honolulu, HI 96814, USA
| | - Jan K Herman
- Bureau of Medicine and Surgery, Falls Church, VA 22042-5113, USA
| | - Firas H Kobeissy
- Psychoproteomics and Neurotechnology Research Center, Department of Psychiatry, University of Florida, Gainesville, FL 32610, USA
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Schwerin SC, Chatterjee M, Hutchinson EB, Djankpa FT, Armstrong RC, McCabe JT, Perl DP, Juliano SL. Expression of GFAP and Tau Following Blast Exposure in the Cerebral Cortex of Ferrets. J Neuropathol Exp Neurol 2021; 80:112-128. [PMID: 33421075 DOI: 10.1093/jnen/nlaa157] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Blast exposures are a hallmark of contemporary military conflicts. We need improved preclinical models of blast traumatic brain injury for translation of pharmaceutical and therapeutic protocols. Compared with rodents, the ferret brain is larger, has substantial sulci, gyri, a higher white to gray matter ratio, and the hippocampus in a ventral position; these attributes facilitate comparison with the human brain. In this study, ferrets received compressed air shock waves and subsequent evaluation of glia and forms of tau following survival of up to 12 weeks. Immunohistochemistry and Western blot demonstrated altered distributions of astrogliosis and tau expression after blast exposure. Many aspects of the astrogliosis corresponded to human pathology: increased subpial reactivity, gliosis at gray-white matter interfaces, and extensive outlining of blood vessels. MRI analysis showed numerous hypointensities occurring in the 12-week survival animals, appearing to correspond to luminal expansions of blood vessels. Changes in forms of tau, including phosphorylated tau, and the isoforms 3R and 4R were noted using immunohistochemistry and Western blot in specific regions of the cerebral cortex. Of particular interest were the 3R and 4R isoforms, which modified their ratio after blast. Our data strongly support the ferret as an animal model with highly translational features to study blast injury.
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Affiliation(s)
- Susan C Schwerin
- From the Department of Anatomy Physiology and Genetics, Uniformed Services University of Health Sciences, Bethesda, Maryland, USA
| | | | - Elizabeth B Hutchinson
- Quantitative Medical Imaging Section, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland, USA
| | - Francis T Djankpa
- From the Department of Anatomy Physiology and Genetics, Uniformed Services University of Health Sciences, Bethesda, Maryland, USA.,Program in Neuroscience, Uniformed Services University of Health Sciences, Bethesda, Maryland, USA.,Department of Physiology, School of Medical Sciences, University of Cape Coast, Ghana
| | - Regina C Armstrong
- From the Department of Anatomy Physiology and Genetics, Uniformed Services University of Health Sciences, Bethesda, Maryland, USA.,Program in Neuroscience, Uniformed Services University of Health Sciences, Bethesda, Maryland, USA
| | - Joseph T McCabe
- From the Department of Anatomy Physiology and Genetics, Uniformed Services University of Health Sciences, Bethesda, Maryland, USA.,Program in Neuroscience, Uniformed Services University of Health Sciences, Bethesda, Maryland, USA
| | - Daniel P Perl
- Program in Neuroscience, Uniformed Services University of Health Sciences, Bethesda, Maryland, USA.,Department of Pathology, Uniformed Services University of Health Sciences, Bethesda, Maryland, USA
| | - Sharon L Juliano
- From the Department of Anatomy Physiology and Genetics, Uniformed Services University of Health Sciences, Bethesda, Maryland, USA.,Program in Neuroscience, Uniformed Services University of Health Sciences, Bethesda, Maryland, USA
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11
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Testing the blast response of foam inserts for helmets. Heliyon 2021; 7:e06990. [PMID: 34036190 PMCID: PMC8134979 DOI: 10.1016/j.heliyon.2021.e06990] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/25/2021] [Accepted: 04/29/2021] [Indexed: 11/20/2022] Open
Abstract
Modern era combat helmets have different iterations and configurations to offer greater protection from blunt impact or ballistic penetration to suit the theatre of operation, although there are currently no standards for blast protection. Moreover, incorporation of blast protection into the same constrained mass-volume envelope is extremely challenging as there is very little space for a material to absorb or dissipate the shockwave. Foam padding is fitted in contemporary combat helmet designs for comfort and standoff purposes. Examples were subjected to blastwaves generated from an air-driven shocktube, along with open cell polyurethane foam specimens of varying pores per inch and thicknesses to. Whilst the range of samples tested did not afford any superior blast mitigation behaviour over the foam already present in helmets, they exhibited comparable performance with a lower mass. There also appears to be positive correlation between increased mass and increased impulse transmitted through the foam. The literature suggests that multiple mechanisms of damage for blast induced mild Traumatic Brain Injury (bTBI) can be caused by the helmet itself, therefore additional protection from a blunt or ballistic impact may increase the risk of damage from a blast insult.
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12
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Marsh JL, Bentil SA. Cerebrospinal Fluid Cavitation as a Mechanism of Blast-Induced Traumatic Brain Injury: A Review of Current Debates, Methods, and Findings. Front Neurol 2021; 12:626393. [PMID: 33776887 PMCID: PMC7994250 DOI: 10.3389/fneur.2021.626393] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 02/18/2021] [Indexed: 11/15/2022] Open
Abstract
Cavitation has gained popularity in recent years as a potential mechanism of blast-induced traumatic brain injury (bTBI). This review presents the most prominent debates on cavitation; how bubbles can form or exist within the cerebrospinal fluid (CSF) and brain vasculature, potential mechanisms of cellular, and tissue level damage following the collapse of bubbles in response to local pressure fluctuations, and a survey of experimental and computational models used to address cavitation research questions. Due to the broad and varied nature of cavitation research, this review attempts to provide a necessary synthesis of cavitation findings relevant to bTBI, and identifies key areas where additional work is required. Fundamental questions about the viability and likelihood of CSF cavitation during blast remain, despite a variety of research regarding potential injury pathways. Much of the existing literature on bTBI evaluates cavitation based off its prima facie plausibility, while more rigorous evaluation of its likelihood becomes increasingly necessary. This review assesses the validity of some of the common assumptions in cavitation research, as well as highlighting outstanding questions that are essential in future work.
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Affiliation(s)
- Jenny L Marsh
- The Bentil Group, Department of Mechanical Engineering, Iowa State University, Ames, IA, United States
| | - Sarah A Bentil
- The Bentil Group, Department of Mechanical Engineering, Iowa State University, Ames, IA, United States
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13
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Hasan F, Al Mahmud KAH, Khan MI, Patil S, Dennis BH, Adnan A. Cavitation Induced Damage in Soft Biomaterials. ACTA ACUST UNITED AC 2021. [DOI: 10.1007/s42493-021-00060-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Traumatic Brain Injury and Inflammation: The Role of Local and Peripheral Participants in Short- and Long-Term Outcomes. J Head Trauma Rehabil 2020; 35:297-299. [PMID: 32881762 DOI: 10.1097/htr.0000000000000623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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15
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Chen Y, O'Shaughnessy TJ, Kamimori GH, Horner DM, Egnoto MJ, Bagchi A. Role of Interfacial Conditions on Blast Overpressure Propagation Into the Brain. Front Neurol 2020; 11:323. [PMID: 32411085 PMCID: PMC7198757 DOI: 10.3389/fneur.2020.00323] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 04/03/2020] [Indexed: 11/13/2022] Open
Abstract
The complex interfacial condition between the human brain and the skull has been difficult to emulate in a surrogate system. Surrogate head models have typically been built using a homogeneous viscoelastic material to represent the brain, but the effect of different interfacial conditions between the brain and the skull on pressure transduction into the brain during blast has not been studied. In the present work, three interfacial conditions were generated in physical surrogate human head models. The first surrogate consisted of a gel brain separated from the skull by a layer of saline solution similar in thickness to the cerebrospinal fluid (CSF) layer in the human head: the fluid interface head model. The second surrogate head had the entire cranial cavity filled with the gel: the fixed interface head model. The third surrogate head contained a space-filling gel brain wrapped in a thin plastic film: the stick-slip interface head model. The human head surrogates were evaluated in a series of frontal blast tests to characterize the effect of skull-brain interfacial conditions on overpressure propagation into the gel brains. The fixed and the stick-slip interface head models showed nearly equal peak brain overpressures. In contrast, the fluid interface head model had much higher in-brain peak overpressures than the other two models, thus representing the largest transmission of forces into the gel brain. Given that the elevated peak overpressures occurred only in the fluid interface head model, the presence of the saline layer is likely responsible for this increase. This phenomenon is hypothesized to be attributed to the incompressibility of the saline and/or the impedance differences between the materials. The fixed interface head model showed pronounced high frequency energy content relative to the other two models, implying that the fluid and the stick-slip conditions provided better dampening. The cumulative impulse energy entering the three brain models were similar, suggesting that the interface conditions do not affect the total energy transmission over the positive phase duration of a blast event. This study shows that the fidelity of the surrogate human head models would improve with a CSF-emulating liquid layer.
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Affiliation(s)
- YungChia Chen
- Multifunctional Materials Branch, US Naval Research Laboratory, Washington, DC, United States
| | - Thomas J O'Shaughnessy
- Multifunctional Materials Branch, US Naval Research Laboratory, Washington, DC, United States
| | - Gary H Kamimori
- Blast Induced Neurotrauma, Walter Reed Army Institute of Research, Silver Springs, MD, United States
| | | | - Michael J Egnoto
- Blast Induced Neurotrauma, Walter Reed Army Institute of Research, Silver Springs, MD, United States
| | - Amit Bagchi
- Multifunctional Materials Branch, US Naval Research Laboratory, Washington, DC, United States
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16
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Venkatasubramanian PN, Keni P, Gastfield R, Li L, Aksenov D, Sherman SA, Bailes J, Sindelar B, Finan JD, Lee J, Bailes JE, Wyrwicz AM. Diffusion Tensor Imaging Detects Acute and Subacute Changes in Corpus Callosum in Blast-Induced Traumatic Brain Injury. ASN Neuro 2020; 12:1759091420922929. [PMID: 32403948 PMCID: PMC7238783 DOI: 10.1177/1759091420922929] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
There is a critical need for understanding the progression of neuropathology in blast-induced traumatic brain injury using valid animal models to develop diagnostic approaches. In the present study, we used diffusion imaging and magnetic resonance (MR) morphometry to characterize axonal injury in white matter structures of the rat brain following a blast applied via blast tube to one side of the brain. Diffusion tensor imaging was performed on acute and subacute phases of pathology from which fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity were calculated for corpus callosum (CC), cingulum bundle, and fimbria. Ventricular volume and CC thickness were measured. Blast-injured rats showed temporally varying bilateral changes in diffusion metrics indicating persistent axonal pathology. Diffusion changes in the CC suggested vasogenic edema secondary to axonal injury in the acute phase. Axonal pathology persisted in the subacute phase marked by cytotoxic edema and demyelination which was confirmed by ultrastructural analysis. The evolution of pathology followed a different pattern in the cingulum bundle: axonal injury and demyelination in the acute phase followed by cytotoxic edema in the subacute phase. Spatially, structures close to midline were most affected. Changes in the genu were greater than in the body and splenium; the caudal cingulum bundle was more affected than the rostral cingulum. Thinning of CC and ventriculomegaly were greater only in the acute phase. Our results reveal the persistent nature of blast-induced axonal pathology and suggest that diffusion imaging may have potential for detecting the temporal evolution of blast injury.
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Affiliation(s)
- Palamadai N Venkatasubramanian
- Center for Basic M.R. Research, Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, United States
| | - Prachi Keni
- Department of Neurosurgery, NorthShore University HealthSystem, Evanston, Illinois, United States
| | - Roland Gastfield
- Center for Basic M.R. Research, Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, United States
| | - Limin Li
- Center for Basic M.R. Research, Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, United States
| | - Daniil Aksenov
- Center for Basic M.R. Research, Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, United States
| | - Sydney A Sherman
- Department of Neurosurgery, NorthShore University HealthSystem, Evanston, Illinois, United States
| | - Julian Bailes
- Department of Neurosurgery, NorthShore University HealthSystem, Evanston, Illinois, United States
| | - Brian Sindelar
- Department of Neurosurgery, NorthShore University HealthSystem, Evanston, Illinois, United States
| | - John D Finan
- Department of Neurosurgery, NorthShore University HealthSystem, Evanston, Illinois, United States
| | - John Lee
- Department of Pathology, NorthShore University HealthSystem, Evanston, Illinois, United States
| | - Julian E Bailes
- Department of Neurosurgery, NorthShore University HealthSystem, Evanston, Illinois, United States
| | - Alice M Wyrwicz
- Center for Basic M.R. Research, Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, United States
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Hartnell D, Gillespie-Jones K, Ciornei C, Hollings A, Thomas A, Harrild E, Reinhardt J, Paterson DJ, Alwis D, Rajan R, Hackett MJ. Characterization of Ionic and Lipid Gradients within Corpus Callosum White Matter after Diffuse Traumatic Brain Injury in the Rat. ACS Chem Neurosci 2020; 11:248-257. [PMID: 31850738 DOI: 10.1021/acschemneuro.9b00257] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
There is increased recognition of the effects of diffuse traumatic brain injury (dTBI), which can initiate yet unknown biochemical cascades, resulting in delayed secondary brain degeneration and long-term neurological sequela. There is limited availability of therapies that minimize the effect of secondary brain damage on the quality of life of people who have suffered TBI, many of which were otherwise healthy adults. Understanding the cascade of biochemical events initiated in specific brain regions in the acute phase of dTBI and how this spreads into adjacent brain structures may provide the necessary insight into drive development of improved therapies. In this study, we have used direct biochemical imaging techniques (Fourier transform infrared spectroscopic imaging) and elemental mapping (X-ray fluorescence microscopy) to characterize biochemical and elemental alterations that occur in corpus callosum white matter in the acute phase of dTBI. The results provide direct visualization of differential biochemical and ionic changes that occur in the highly vulnerable medial corpus callosum white matter relative to the less vulnerable lateral regions of the corpus callosum. Specifically, the results suggest that altered ionic gradients manifest within mechanically damaged medial corpus callosum, potentially spreading to and inducing lipid alterations to white matter structures in lateral brain regions.
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Affiliation(s)
- David Hartnell
- Curtin Institute for Functional Molecules and Interfaces, School of Molecular and Life Sciences, Curtin University, Perth, Western Australia, Australia 6845
- Curtin Health Innovation Research Institute, Curtin University, Perth, AUS 6102
| | - Kate Gillespie-Jones
- Neuroscience Program, Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, Victoria, Australia 3168
| | - Cristina Ciornei
- Neuroscience Program, Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, Victoria, Australia 3168
| | - Ashley Hollings
- Curtin Institute for Functional Molecules and Interfaces, School of Molecular and Life Sciences, Curtin University, Perth, Western Australia, Australia 6845
- Curtin Health Innovation Research Institute, Curtin University, Perth, AUS 6102
| | - Alexander Thomas
- Curtin Institute for Functional Molecules and Interfaces, School of Molecular and Life Sciences, Curtin University, Perth, Western Australia, Australia 6845
- Curtin Health Innovation Research Institute, Curtin University, Perth, AUS 6102
| | - Elizabeth Harrild
- Curtin Institute for Functional Molecules and Interfaces, School of Molecular and Life Sciences, Curtin University, Perth, Western Australia, Australia 6845
- Curtin Health Innovation Research Institute, Curtin University, Perth, AUS 6102
| | - Juliane Reinhardt
- Australian Nuclear Science and Technology Organisation, 800 Blackburn Road, Clayton, Victoria, Australia 3168
- Department of Chemistry and Physics, ARC Centre of Excellence for Advanced Molecular Imaging, Institute for Molecular Sciences, La Trobe University, Melbourne, Victoria, Australia 3086
| | - David J. Paterson
- Australian Nuclear Science and Technology Organisation, 800 Blackburn Road, Clayton, Victoria, Australia 3168
| | - Dasuni Alwis
- Neuroscience Program, Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, Victoria, Australia 3168
| | - Ramesh Rajan
- Neuroscience Program, Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, Victoria, Australia 3168
| | - Mark J. Hackett
- Curtin Institute for Functional Molecules and Interfaces, School of Molecular and Life Sciences, Curtin University, Perth, Western Australia, Australia 6845
- Curtin Health Innovation Research Institute, Curtin University, Perth, AUS 6102
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18
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Bryden DW, Tilghman JI, Hinds SR. Blast-Related Traumatic Brain Injury: Current Concepts and Research Considerations. J Exp Neurosci 2019; 13:1179069519872213. [PMID: 31548796 PMCID: PMC6743194 DOI: 10.1177/1179069519872213] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 08/02/2019] [Indexed: 01/12/2023] Open
Abstract
Traumatic brain injury (TBI) is a well-known consequence of participation in
activities such as military combat or collision sports. But the wide variability
in eliciting circumstances and injury severities makes the study of TBI as a
uniform disease state impossible. Military Service members are under additional,
unique threats such as exposure to explosive blast and its unique effects on the
body. This review is aimed toward TBI researchers, as it covers important
concepts and considerations for studying blast-induced head trauma. These
include the comparability of blast-induced head trauma to other mechanisms of
TBI, whether blast overpressure induces measureable biomarkers, and whether a
biodosimeter can link blast exposure to health outcomes, using acute radiation
exposure as a corollary. This examination is contextualized by the understanding
of concussive events and their psychological effects throughout the past
century’s wars, as well as the variables that predict sustaining a TBI and those
that precipitate or exacerbate psychological conditions. Disclaimer: The views expressed in this article are solely the views of the
authors and not those of the Department of Defense Blast Injury Research
Coordinating Office, US Army Medical Research and Development Command, US Army
Futures Command, US Army, or the Department of Defense.
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Affiliation(s)
- Daniel W Bryden
- Booz Allen Hamilton, contract support to DoD Blast Injury Research Coordinating Office, US Army Medical Research and Development Command, Fort Detrick, MD, USA
| | - Jessica I Tilghman
- Booz Allen Hamilton, contract support to DoD Blast Injury Research Coordinating Office, US Army Medical Research and Development Command, Fort Detrick, MD, USA
| | - Sidney R Hinds
- DoD Blast Injury Research Coordinating Office, US Army Medical Research and Development Command, Fort Detrick, MD, USA
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19
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Przekwas A, Garimella HT, Tan XG, Chen ZJ, Miao Y, Harrand V, Kraft RH, Gupta RK. Biomechanics of Blast TBI With Time-Resolved Consecutive Primary, Secondary, and Tertiary Loads. Mil Med 2019; 184:195-205. [DOI: 10.1093/milmed/usy344] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 10/29/2018] [Indexed: 12/29/2022] Open
Abstract
Abstract
Blast-induced traumatic brain injury (bTBI) has become a signature casualty of recent military operations. In spite of significant clinical and preclinical TBI research, current understanding of injury mechanisms and short- and long-term outcomes is limited. Mathematical models of bTBI biomechanics may help in better understanding of injury mechanisms and in the development of improved neuroprotective strategies. Until present, bTBI has been analyzed as a single event of a blast pressure wave propagating through the brain. In many bTBI events, the loads on the body and the head are spatially and temporarily distributed, involving the primary intracranial pressure wave, followed by the head rotation and then by head impact on the ground. In such cases, the brain microstructures may experience time/space distributed (consecutive) damage and recovery events. The paper presents a novel multiscale simulation framework that couples the body/brain scale biomechanics with micro-scale mechanobiology to study the effects of micro-damage to neuro-axonal structures. Our results show that the micro-mechanical responses of neuro-axonal structures occur sequentially in time with “damage” and “relaxation” periods in different parts of the brain. A new integrated computational framework is described coupling the brain-scale biomechanics with micro-mechanical damage to axonal and synaptic structures.
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Affiliation(s)
| | | | - X Gary Tan
- US Naval Research Laboratory, 4555 Overlook Ave., Washington, DC
| | - Z J Chen
- CFD Research Corp., 701 McMillan Way NW, Huntsville, AL
| | - Yuyang Miao
- CFD Research Corp., 701 McMillan Way NW, Huntsville, AL
| | | | - Reuben H Kraft
- Pennsylvania State University, 320 Leonhard Building, University Park, PA
| | - Raj K Gupta
- DoD Blast Program Coordinating Office, US Army MRMC, 504 Scott Street, Fort Detrick, MD
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20
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BERTUCCI ROBBIN, PRABHU RAJ, HORSTEMEYER MF, MAO YUXIONG, GILBRECH RYAN, SHENG JAMES, WILLIAMS LAKIESHAN, LIAO JUN. AN ANATOMICALLY-RELEVANT COMPUTATIONAL MODEL FOR PRIMARY BLAST EFFECTS ON THE HUMAN LOWER EXTREMITY. J MECH MED BIOL 2018. [DOI: 10.1142/s0219519418500574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Explosions pose serious threats to US soldiers and civilians, often resulting in disability and death. Due to its direct contact with the ground, the lower extremity is commonly injured, and the blast loading often results in traumatic amputations and soft tissue rupture. The exact overpressure signatures that induce these primary blast injuries are still unknown. A high fidelity FE model of the lower extremity blast condition is thus essential to reveal the underlying injury mechanism. In this study, we created an anatomically-relevant lower extremity model and analyzed several different blast cases using Abaqus/Explicit. Pressures, impulses, stresses, and maximum principal strains were evaluated and compared to previous results in the literature. Our FE model and simulation were able to capture the detailed structural responses to a blast wave in the lower extremity; moreover, we showed that the injury patterns could be correlated to biomechanical metrics that may have incited pathologies such as amputations and compartment syndrome. The lower extremity FE model developed in this project allows for a cost-effective and reproducible analysis of blast events and has the potential to improve injury metrics and personal protective equipment design by accurately evaluating the damage imposed on the lower extremity.
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Affiliation(s)
- ROBBIN BERTUCCI
- Department of Biological Engineering, Mississippi State University, Mississippi State, MS 39762, USA
| | - RAJ PRABHU
- Department of Biological Engineering, Mississippi State University, Mississippi State, MS 39762, USA
| | - M. F. HORSTEMEYER
- Center for Advanced Vehicular Systems, Mississippi State University, Mississippi State, MS 39762, USA
| | - YUXIONG MAO
- Center for Advanced Vehicular Systems, Mississippi State University, Mississippi State, MS 39762, USA
| | - RYAN GILBRECH
- Department of Biological Engineering, Mississippi State University, Mississippi State, MS 39762, USA
| | - JAMES SHENG
- U. S. Army Tank Automotive Research, Development and Engineering Center (TARDEC), USA
| | - LAKIESHA N. WILLIAMS
- Department of Biological Engineering, Mississippi State University, Mississippi State, MS 39762, USA
| | - JUN LIAO
- Department of Biological Engineering, Mississippi State University, Mississippi State, MS 39762, USA
- Department of Bioengineering, University of Texas, Arlington, TX 79010, USA
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21
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Brady RD, Casillas-Espinosa PM, Agoston DV, Bertram EH, Kamnaksh A, Semple BD, Shultz SR. Modelling traumatic brain injury and posttraumatic epilepsy in rodents. Neurobiol Dis 2018; 123:8-19. [PMID: 30121231 DOI: 10.1016/j.nbd.2018.08.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Revised: 07/25/2018] [Accepted: 08/13/2018] [Indexed: 12/14/2022] Open
Abstract
Posttraumatic epilepsy (PTE) is one of the most debilitating and understudied consequences of traumatic brain injury (TBI). It is challenging to study the effects, underlying pathophysiology, biomarkers, and treatment of TBI and PTE purely in human patients for a number of reasons. Rodent models can complement human PTE studies as they allow for the rigorous investigation into the causal relationship between TBI and PTE, the pathophysiological mechanisms of PTE, the validation and implementation of PTE biomarkers, and the assessment of PTE treatments, in a tightly controlled, time- and cost-efficient manner in experimental subjects known to be experiencing epileptogenic processes. This article will review several common rodent models of TBI and/or PTE, including their use in previous studies and discuss their relative strengths, limitations, and avenues for future research to advance our understanding and treatment of PTE.
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Affiliation(s)
- Rhys D Brady
- Departments of Neuroscience and Medicine, Central Clinical School, Monash University, VIC 3004, Australia; Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, VIC 3052, Australia.
| | - Pablo M Casillas-Espinosa
- Departments of Neuroscience and Medicine, Central Clinical School, Monash University, VIC 3004, Australia; Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, VIC 3052, Australia.
| | - Denes V Agoston
- Anatomy, Physiology & Genetics, Uniformed Services University, Bethesda, MD 20814, USA
| | - Edward H Bertram
- Department of Neurology, University of Virginia, P.O. Box 800394, Charlottesville, VA 22908-0394, USA
| | - Alaa Kamnaksh
- Anatomy, Physiology & Genetics, Uniformed Services University, Bethesda, MD 20814, USA
| | - Bridgette D Semple
- Departments of Neuroscience and Medicine, Central Clinical School, Monash University, VIC 3004, Australia; Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, VIC 3052, Australia
| | - Sandy R Shultz
- Departments of Neuroscience and Medicine, Central Clinical School, Monash University, VIC 3004, Australia; Department of Medicine, The Royal Melbourne Hospital, The University of Melbourne, VIC 3052, Australia
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22
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Agoston DV. Modeling the Long-Term Consequences of Repeated Blast-Induced Mild Traumatic Brain Injuries. J Neurotrauma 2018; 34:S44-S52. [PMID: 28937952 DOI: 10.1089/neu.2017.5317] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Repeated mild traumatic brain injury (rmTBI) caused by playing collision sports or by exposure to blasts during military operations can lead to late onset, chronic diseases such as chronic traumatic encephalopathy (CTE), a progressive neurodegenerative condition that manifests in increasingly severe neuropsychiatric abnormalities years after the last injury. Currently, because of the heterogeneity of the clinical presentation, confirmation of a CTE diagnosis requires post-mortem examination of the brain. The hallmarks of CTE are abnormal accumulation of phosphorylated tau protein, TDP-43 immunoreactive neuronal cytoplasmic inclusions, and astroglial abnormalities, but the pathomechanism leading to these terminal findings remains unknown. Animal modeling can play an important role in the identification of CTE pathomechanisms, the development of early stage diagnostic and prognostic biomarkers, and pharmacological interventions. Modeling the long-term consequences of blast rmTBI in animals is especially challenging because of the complexities of blast physics and animal-to-human scaling issues. This review summarizes current knowledge about the pathobiologies of CTE and rmbTBI and discusses problems as well as potential solutions related to high-fidelity modeling of rmbTBI and determining its long-term consequences.
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Affiliation(s)
- Denes V Agoston
- Department of Anatomy, Physiology and Genetics, Uniformed Services University , Bethesda, Maryland; Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
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23
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Do blast induced skull flexures result in axonal deformation? PLoS One 2018; 13:e0190881. [PMID: 29547663 PMCID: PMC5856259 DOI: 10.1371/journal.pone.0190881] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 12/21/2017] [Indexed: 12/28/2022] Open
Abstract
Subject-specific computer models (male and female) of the human head were used to investigate the possible axonal deformation resulting from the primary phase blast-induced skull flexures. The corresponding axonal tractography was explicitly incorporated into these finite element models using a recently developed technique based on the embedded finite element method. These models were subjected to extensive verification against experimental studies which examined their pressure and displacement response under a wide range of loading conditions. Once verified, a parametric study was developed to investigate the axonal deformation for a wide range of loading overpressures and directions as well as varying cerebrospinal fluid (CSF) material models. This study focuses on early times during a blast event, just as the shock transverses the skull (< 5 milliseconds). Corresponding boundary conditions were applied to eliminate the rotation effects and the resulting axonal deformation. A total of 138 simulations were developed– 128 simulations for studying the different loading scenarios and 10 simulations for studying the effects of CSF material model variance–leading to a total of 10,702 simulation core hours. Extreme strains and strain rates along each of the fiber tracts in each of these scenarios were documented and presented here. The results suggest that the blast-induced skull flexures result in strain rates as high as 150–378 s-1. These high-strain rates of the axonal fiber tracts, caused by flexural displacement of the skull, could lead to a rate dependent micro-structural axonal damage, as pointed by other researchers.
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Song H, Cui J, Simonyi A, Johnson CE, Hubler GK, DePalma RG, Gu Z. Linking blast physics to biological outcomes in mild traumatic brain injury: Narrative review and preliminary report of an open-field blast model. Behav Brain Res 2018; 340:147-158. [DOI: 10.1016/j.bbr.2016.08.037] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 08/13/2016] [Accepted: 08/19/2016] [Indexed: 12/14/2022]
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Abstract
Blast injuries affect millions of lives across the globe due to its traumatic after effects on the brain and the whole body. To date, military grade armour materials are designed to mitigate ballistic and shrapnel attacks but are less effective in resisting blast impacts. In order to improve blast absorption characteristics of armours, the first key step is thoroughly understands the effects of blasts on the human body itself. In the last decade, a plethora of experimental and computational work has been carried out to investigate the mechanics and pathophysiology of Traumatic Brain Injury (TBI). However, very few attempts have been made so far to study the effect of blasts on the various other parts of the body such as the sensory organs (eyes and ears), nervous system, thorax, extremities, internal organs (such as the lungs) and the skeletal system. While an experimental evaluation of blast effects on such physiological systems is difficult, developing finite element (FE) models could allow the recreation of realistic blast scenarios on full scale human models and simulate the effects. The current article reviews the state-of-the-art in computational research in blast induced whole-body injury modelling, which would not only help in identifying the areas in which further research is required, but would also be indispensable for understanding body location specific armour design criteria for improved blast injury mitigation.
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Affiliation(s)
- Arnab Chanda
- a Department of Aerospace Engineering and Mechanics , University of Alabama , Tuscaloosa , AL , USA
| | - Christian Callaway
- b Department of Mechanical Engineering , University of Alabama , Tuscaloosa , AL , USA
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26
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Yamamoto S, DeWitt DS, Prough DS. Impact & Blast Traumatic Brain Injury: Implications for Therapy. Molecules 2018; 23:E245. [PMID: 29373501 PMCID: PMC6017013 DOI: 10.3390/molecules23020245] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Revised: 01/22/2018] [Accepted: 01/24/2018] [Indexed: 12/23/2022] Open
Abstract
Traumatic brain injury (TBI) is one of the most frequent causes of combat casualties in Operations Iraqi Freedom (OIF), Enduring Freedom (OEF), and New Dawn (OND). Although less common than combat-related blast exposure, there have been significant numbers of blast injuries in civilian populations in the United States. Current United States Department of Defense (DoD) ICD-9 derived diagnoses of TBI in the DoD Health Care System show that, for 2016, severe and moderate TBIs accounted for just 0.7% and 12.9%, respectively, of the total of 13,634 brain injuries, while mild TBIs (mTBIs) accounted for 86% of the total. Although there is a report that there are differences in the frequency of long-term complications in mTBI between blast and non-blast TBIs, clinical presentation is classified by severity score rather than mechanism because severity scoring is associated with prognosis in clinical practice. Blast TBI (bTBI) is unique in its pathology and mechanism, but there is no treatment specific for bTBIs-these patients are treated similarly to TBIs in general and therapy is tailored on an individual basis. Currently there is no neuroprotective drug recommended by the clinical guidelines based on evidence.
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Affiliation(s)
- Satoshi Yamamoto
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX 77555, USA.
| | - Douglas S DeWitt
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX 77555, USA.
| | - Donald S Prough
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX 77555, USA.
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27
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Somayaji MR, Przekwas AJ, Gupta RK. Combination Therapy for Multi-Target Manipulation of Secondary Brain Injury Mechanisms. Curr Neuropharmacol 2018; 16:484-504. [PMID: 28847295 PMCID: PMC6018188 DOI: 10.2174/1570159x15666170828165711] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 02/10/2017] [Accepted: 03/28/2017] [Indexed: 12/14/2022] Open
Abstract
Traumatic brain injury (TBI) is a major healthcare problem that affects millions of people worldwide. Despite advances in understanding and developing preventative and treatment strategies using preclinical animal models, clinical trials to date have failed, and a 'magic bullet' for effectively treating TBI-induced damage does not exist. Thus, novel pharmacological strategies to effectively manipulate the complex and heterogeneous pathophysiology of secondary injury mechanisms are needed. Given that goal, this paper discusses the relevance and advantages of combination therapies (COMTs) for 'multi-target manipulation' of the secondary injury cascade by administering multiple drugs to achieve an optimal therapeutic window of opportunity (e.g., temporally broad window) and compares these regimens to monotherapies that manipulate a single target with a single drug at a given time. Furthermore, we posit that integrated mechanistic multiscale models that combine primary injury biomechanics, secondary injury mechanobiology/neurobiology, physiology, pharmacology and mathematical programming techniques could account for vast differences in the biological space and time scales and help to accelerate drug development, to optimize pharmacological COMT protocols and to improve treatment outcomes.
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Affiliation(s)
| | | | - Raj K. Gupta
- Department of Defense Blast Injury Research Program Coordinating Office, U.S. Army Medical Research and Materiel Command, Fort Detrick, MD, USA
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28
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Pak J, Chen ZJ, Sun K, Przekwas A, Walenga R, Fan J. Computational modeling of drug transport across the in vitro cornea. Comput Biol Med 2017; 92:139-146. [PMID: 29175100 DOI: 10.1016/j.compbiomed.2017.11.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 11/09/2017] [Accepted: 11/12/2017] [Indexed: 12/12/2022]
Abstract
A novel quasi-3D (Q3D) modeling approach was developed to model networks of one dimensional structures like tubes and vessels common in human anatomy such as vascular and lymphatic systems, neural networks, and respiratory airways. Instead of a branching network of the same tissue type, this approach was extended to model an interconnected stack of different corneal tissue layers with membrane junction conditions assigned between the tissues. The multi-laminate structure of the cornea presents a unique barrier design and opportunity for investigation using Q3D modeling. A Q3D model of an in vitro rabbit cornea was created to simulate the drug transport across the cornea, accounting for transcellular and paracellular pathways of passive and convective drug transport as well as physicochemistry of lipophilic partitioning and protein binding. Lipophilic Rhodamine B and hydrophilic fluorescein were used as drug analogs. The model predictions for both hydrophilic and lipophilic tracers were able to match the experimental measurements along with the sharp discontinuities at the epithelium-stroma and stroma-endothelium interfaces. This new modeling approach was successfully applied towards pharmacokinetic modeling for use in topical ophthalmic drug design.
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Affiliation(s)
- Joseph Pak
- CFD Research Corporation, 701 McMillian Way NW, Suite D, Huntsville, AL 35806, USA
| | - Z J Chen
- CFD Research Corporation, 701 McMillian Way NW, Suite D, Huntsville, AL 35806, USA
| | - Kay Sun
- CFD Research Corporation, 701 McMillian Way NW, Suite D, Huntsville, AL 35806, USA.
| | - Andrzej Przekwas
- CFD Research Corporation, 701 McMillian Way NW, Suite D, Huntsville, AL 35806, USA
| | - Ross Walenga
- Office of Generic Drugs, Food and Drug Administration, Silver Spring, MD, USA
| | - Jianghong Fan
- Office of Generic Drugs, Food and Drug Administration, Silver Spring, MD, USA
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29
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Cernak I. Understanding blast-induced neurotrauma: how far have we come? Concussion 2017; 2:CNC42. [PMID: 30202583 PMCID: PMC6093818 DOI: 10.2217/cnc-2017-0006] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 05/08/2017] [Indexed: 12/14/2022] Open
Abstract
Blast injuries, including blast-induced neurotrauma (BINT), are caused by blast waves generated during an explosion. Accordingly, their history coincides with that of explosives. Hence, it is intriguing that, after more than 1000 years of using explosives, our understanding of the pathological consequences of blast and body/brain interactions is extremely limited. Postconflict recovery mechanisms seemingly include the suppression of painful experiences, such as explosive injuries. Unfortunately, ignoring the knowledge generated by previous generations of scientists retards research progress, leading to superfluous and repetitive studies. This article summarizes clinical and experimental findings published about blast injuries and BINT following the wars of the 20th and 21th centuries. Moreover, it offers a personal view on potential factors interfering with the progress of BINT research working toward providing better diagnosis, treatment and rehabilitation for military personnel affected by blast exposure.
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Affiliation(s)
- Ibolja Cernak
- Faculty of Rehabilitation Medicine, University of Alberta, Corbett Hall 3–48, Edmonton Alberta, T6G 2G4, Canada
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30
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Singh K, Trivedi R, Verma A, D'souza MM, Koundal S, Rana P, Baishya B, Khushu S. Altered metabolites of the rat hippocampus after mild and moderate traumatic brain injury - a combined in vivo and in vitro 1 H-MRS study. NMR IN BIOMEDICINE 2017; 30:e3764. [PMID: 28759166 DOI: 10.1002/nbm.3764] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 05/13/2017] [Accepted: 05/28/2017] [Indexed: 06/07/2023]
Abstract
Traumatic brain injury (TBI) has been shown to affect hippocampus-associated learning, memory and higher cognitive functions, which may be a consequence of metabolic alterations. Hippocampus-associated disorders may vary depending on the severity of injury [mild TBI (miTBI) and moderate TBI (moTBI)] and time since injury. The underlying hippocampal metabolic irregularities may provide an insight into the pathological process following TBI. In this study, in vivo and in vitro proton magnetic resonance spectroscopy (1 H-MRS) data were acquired from the hippocampus region of controls and TBI groups (miTBI and moTBI) at D0 (pre-injury), 4 h, Day 1 and Day 5 post-injury (PI). In vitro MRS results indicated trauma-induced changes in both miTBI and moTBI; however, in vivo MRS showed metabolic alterations in moTBI only. miTBI and moTBI showed elevated levels of osmolytes indicating injury-induced edema. Altered levels of citric acid cycle intermediates, glutamine/glutamate and amino acid metabolism indicated injury-induced aberrant bioenergetics, excitotoxicity and oxidative stress. An overall similar pattern of pathological process was observed in both miTBI and moTBI, with the distinction of depleted N-acetylaspartate levels (indicating neuronal loss) at 4 h and Day 1 and enhanced lactate production (indicating heightened energy depletion leading to the commencement of the anaerobic pathway) at Day 5 in moTBI. To the best of our knowledge, this is the first study to investigate the hippocampus metabolic profile in miTBI and moTBI simultaneously using in vivo and in vitro MRS.
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Affiliation(s)
- Kavita Singh
- NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences, Delhi, India
| | - Richa Trivedi
- NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences, Delhi, India
| | - Ajay Verma
- Centre for Biomedical Magnetic Resonance (CBMR), SGPGIMS Campus, Lucknow, Uttar Pradesh, India
| | - Maria M D'souza
- NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences, Delhi, India
| | - Sunil Koundal
- NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences, Delhi, India
| | - Poonam Rana
- NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences, Delhi, India
| | - Bikash Baishya
- Centre for Biomedical Magnetic Resonance (CBMR), SGPGIMS Campus, Lucknow, Uttar Pradesh, India
| | - Subash Khushu
- NMR Research Centre, Institute of Nuclear Medicine and Allied Sciences, Delhi, India
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31
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Ng LJ, Volman V, Gibbons MM, Phohomsiri P, Cui J, Swenson DJ, Stuhmiller JH. A Mechanistic End-to-End Concussion Model That Translates Head Kinematics to Neurologic Injury. Front Neurol 2017; 8:269. [PMID: 28663736 PMCID: PMC5471336 DOI: 10.3389/fneur.2017.00269] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 05/26/2017] [Indexed: 11/13/2022] Open
Abstract
Past concussion studies have focused on understanding the injury processes occurring on discrete length scales (e.g., tissue-level stresses and strains, cell-level stresses and strains, or injury-induced cellular pathology). A comprehensive approach that connects all length scales and relates measurable macroscopic parameters to neurological outcomes is the first step toward rationally unraveling the complexity of this multi-scale system, for better guidance of future research. This paper describes the development of the first quantitative end-to-end (E2E) multi-scale model that links gross head motion to neurological injury by integrating fundamental elements of tissue and cellular mechanical response with axonal dysfunction. The model quantifies axonal stretch (i.e., tension) injury in the corpus callosum, with axonal functionality parameterized in terms of axonal signaling. An internal injury correlate is obtained by calculating a neurological injury measure (the average reduction in the axonal signal amplitude) over the corpus callosum. By using a neurologically based quantity rather than externally measured head kinematics, the E2E model is able to unify concussion data across a range of exposure conditions and species with greater sensitivity and specificity than correlates based on external measures. In addition, this model quantitatively links injury of the corpus callosum to observed specific neurobehavioral outcomes that reflect clinical measures of mild traumatic brain injury. This comprehensive modeling framework provides a basis for the systematic improvement and expansion of this mechanistic-based understanding, including widening the range of neurological injury estimation, improving concussion risk correlates, guiding the design of protective equipment, and setting safety standards.
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Affiliation(s)
- Laurel J Ng
- Simulation Engineering and Testing, L-3 Applied Technologies, Inc., San Diego, CA, United States
| | - Vladislav Volman
- Simulation Engineering and Testing, L-3 Applied Technologies, Inc., San Diego, CA, United States
| | - Melissa M Gibbons
- Simulation Engineering and Testing, L-3 Applied Technologies, Inc., San Diego, CA, United States
| | - Pi Phohomsiri
- Simulation Engineering and Testing, L-3 Applied Technologies, Inc., San Diego, CA, United States
| | - Jianxia Cui
- Simulation Engineering and Testing, L-3 Applied Technologies, Inc., San Diego, CA, United States
| | - Darrell J Swenson
- Cardiac Rhythm and Heart Failure Numerical Modeling, Medtronic, Mounds View, MN, United States
| | - James H Stuhmiller
- Simulation Engineering and Testing, L-3 Applied Technologies, Inc., San Diego, CA, United States
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32
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Boothe DL, Yu AB, Kudela P, Anderson WS, Vettel JM, Franaszczuk PJ. Impact of Neuronal Membrane Damage on the Local Field Potential in a Large-Scale Simulation of Cerebral Cortex. Front Neurol 2017. [PMID: 28638364 PMCID: PMC5461262 DOI: 10.3389/fneur.2017.00236] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Within multiscale brain dynamics, the structure–function relationship between cellular changes at a lower scale and coordinated oscillations at a higher scale is not well understood. This relationship may be particularly relevant for understanding functional impairments after a mild traumatic brain injury (mTBI) when current neuroimaging methods do not reveal morphological changes to the brain common in moderate to severe TBI such as diffuse axonal injury or gray matter lesions. Here, we created a physiology-based model of cerebral cortex using a publicly released modeling framework (GEneral NEural SImulation System) to explore the possibility that performance deficits characteristic of blast-induced mTBI may reflect dysfunctional, local network activity influenced by microscale neuronal damage at the cellular level. We operationalized microscale damage to neurons as the formation of pores on the neuronal membrane based on research using blast paradigms, and in our model, pores were simulated by a change in membrane conductance. We then tracked changes in simulated electrical activity. Our model contained 585 simulated neurons, comprised of 14 types of cortical and thalamic neurons each with its own compartmental morphology and electrophysiological properties. Comparing the functional activity of neurons before and after simulated damage, we found that simulated pores in the membrane reduced both action potential generation and local field potential (LFP) power in the 1–40 Hz range of the power spectrum. Furthermore, the location of damage modulated the strength of these effects: pore formation on simulated axons reduced LFP power more strongly than did pore formation on the soma and the dendrites. These results indicate that even small amounts of cellular damage can negatively impact functional activity of larger scale oscillations, and our findings suggest that multiscale modeling provides a promising avenue to elucidate these relationships.
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Affiliation(s)
- David L Boothe
- U.S. Army Research Laboratory, Aberdeen Proving Ground, Aberdeen, MD, United States.,Altus Engineering, Churchville, MD, United States
| | - Alfred B Yu
- U.S. Army Research Laboratory, Aberdeen Proving Ground, Aberdeen, MD, United States
| | - Pawel Kudela
- Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, MD, United States.,The Johns Hopkins Institute for Clinical and Translational Research, Baltimore, MD, United States
| | - William S Anderson
- Department of Neurosurgery, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Jean M Vettel
- U.S. Army Research Laboratory, Aberdeen Proving Ground, Aberdeen, MD, United States.,Psychological & Brain Sciences, University of California, Santa Barbara, CA, United States.,Department of Engineering, University of Pennsylvania, Philadelphia, PA, United States
| | - Piotr J Franaszczuk
- U.S. Army Research Laboratory, Aberdeen Proving Ground, Aberdeen, MD, United States.,Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
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33
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Ivanov I, Fernandez C, Mitsis EM, Dickstein DL, Wong E, Tang CY, Simantov J, Bang C, Moshier E, Sano M, Elder GA, Hazlett EA. Blast Exposure, White Matter Integrity, and Cognitive Function in Iraq and Afghanistan Combat Veterans. Front Neurol 2017; 8:127. [PMID: 28484418 PMCID: PMC5399028 DOI: 10.3389/fneur.2017.00127] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 03/17/2017] [Indexed: 01/01/2023] Open
Abstract
The long-term effects of blast exposure are a major health concern for combat veterans returning from the recent conflicts in Iraq and Afghanistan. We used an optimized diffusion tensor imaging tractography algorithm to assess white matter (WM) fractional anisotropy (FA) in blast-exposed Iraq and Afghanistan veterans (n = 40) scanned on average 3.7 years after deployment/trauma exposure. Veterans diagnosed with a blast-related mild traumatic brain injury (mTBI) were compared to combat veterans with blast exposure but no TBI diagnosis. Blast exposure was associated with decreased FA in several WM tracts. However, total blast exposure did not correlate well with neuropsychological testing performance and there were no differences in FA based on mTBI diagnosis. Yet, veterans with mTBI performed worse on every neurocognitive test administered. Multiple linear regression across all blast-exposed veterans using a six-factor prediction model indicated that the amount of blast exposure accounted for 11–15% of the variability in composite FA scores such that as blast exposure increased, FA decreased. Education accounted for 10% of the variability in composite FA scores and 25–32% of FA variability in the right cingulum, such that as level of education increased, FA increased. Total blast exposure, age, and education were significant predictors of FA in the left cingulum. We did not find any effect of post-traumatic stress disorder on cognition or composite FA. In summary, our findings suggest that greater total blast exposure is a contributing factor to poor WM integrity. While FA was not associated with neurocognitive performance, we hypothesize that FA changes in the cingulum in veterans with multiple combat exposures and no head trauma prior to deployment may represent a marker of vulnerability for future deficits. Future work needs to examine this longitudinally.
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Affiliation(s)
- Iliyan Ivanov
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Corey Fernandez
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Research & Development, James J. Peters Veterans Affairs Medical Center, Bronx, NY, USA
| | - Effie M Mitsis
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Rehabilitation Medicine Service, James J. Peters Veterans Affairs Medical Center, Bronx, NY, USA
| | - Dara L Dickstein
- Department of Pathology, Uniformed Service University of Health Science, Bethesda, MD, USA.,Fishberg Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Edmund Wong
- Department of Radiology, Icahn School of Medicine at Mount Sinai, Translational and Molecular Imaging Institute, New York, NY, USA
| | - Cheuk Y Tang
- Department of Radiology, Icahn School of Medicine at Mount Sinai, Translational and Molecular Imaging Institute, New York, NY, USA
| | - Jessie Simantov
- Rehabilitation Medicine Service, James J. Peters Veterans Affairs Medical Center, Bronx, NY, USA.,Department of Rehabilitation Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Charlene Bang
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Rehabilitation Medicine Service, James J. Peters Veterans Affairs Medical Center, Bronx, NY, USA
| | - Erin Moshier
- Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Mary Sano
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Research & Development, James J. Peters Veterans Affairs Medical Center, Bronx, NY, USA
| | - Gregory A Elder
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Neurology Service, James J. Peters Veterans Affairs Medical Center, Bronx, NY, USA
| | - Erin A Hazlett
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Research & Development, James J. Peters Veterans Affairs Medical Center, Bronx, NY, USA.,Fishberg Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Mental Illness Research, Education, and Clinical Center (MIRECC VISN 2 South), James J. Peters Veterans Affairs Medical Center, Bronx, NY, USA
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34
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Protection against Blast-Induced Traumatic Brain Injury by Increase in Brain Volume. BIOMED RESEARCH INTERNATIONAL 2017; 2017:2075463. [PMID: 28553646 PMCID: PMC5434276 DOI: 10.1155/2017/2075463] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 02/13/2017] [Accepted: 03/23/2017] [Indexed: 11/18/2022]
Abstract
Blast-induced traumatic brain injury (bTBI) is a leading cause of injuries in recent military conflicts and it is responsible for an increased number of civilian casualties by terrorist attacks. bTBI includes a variety of neuropathological changes depending on the intensity of blast overpressure (BOP) such as brain edema, neuronal degeneration, diffuse axonal damage, and vascular dysfunction with neurological manifestations of psychological and cognitive abnormalities. Internal jugular vein (IJV) compression is known to reduce intracranial compliance by causing an increase in brain volume and was shown to reduce brain damage during closed impact-induced TBI. We investigated whether IJV compression can attenuate signs of TBI in rats after exposure to BOP. Animals were exposed to three 110 ± 5 kPa BOPs separated by 30 min intervals. Exposure to BOP resulted in a significant decrease of neuronal nuclei (NeuN) together with upregulation of aquaporin-4 (AQP-4), 3-nitrotyrosine (3-NT), and endothelin 1 receptor A (ETRA) expression in frontal cortex and hippocampus one day following exposures. IJV compression attenuated this BOP-induced increase in 3-NT in cortex and ameliorated the upregulation of AQP-4 in hippocampus. These results suggest that elevated intracranial pressure and intracerebral volume have neuroprotective potential in blast-induced TBI.
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35
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Yan W, Sossou G, Rajan R. A multi-body dynamics study on a weight-drop test of rat brain injury. Comput Methods Biomech Biomed Engin 2017; 20:602-616. [PMID: 28090780 DOI: 10.1080/10255842.2017.1280733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Traumatic brain injury (TBI), induced by impact of an object with the head, is a major health problem worldwide. Rats are a well-established animal analogue for study of TBI and the weight-drop impact-acceleration (WDIA) method is a well-established model in rats for creating diffuse TBI, the most common form of TBI seen in humans. However, little is known of the biomechanics of the WDIA method and, to address this, we have developed a four-degrees-of-freedom multi-body mass-spring-damper model for the WDIA test in rats. An analytical expression of the maximum skull acceleration, one of the important head injury predictor, was derived and it shows that the maximum skull acceleration is proportional to the impact velocity but independent of the impactor mass. Furthermore, a dimensional analysis disclosed that the maximum force on the brain and maximum relative displacement between brain and skull are also linearly proportional to impact velocity. Additionally, the effects of the impactor mass were examined through a parametric study from the developed multi-body dynamics model. It was found that increasing impactor mass increased these two brain injury predictors.
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Affiliation(s)
- Wenyi Yan
- a Department of Mechanical & Aerospace Engineering , Monash University , Clayton , Australia
| | - Germain Sossou
- b École Nationale Supérieure de Mécanique et d'Aérotechnique , Futuroscope Chasseneuil Cedex , France
| | - Ramesh Rajan
- c Department of Physiology , Monash University , Clayton , Australia
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36
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KURTOGLU E, NAKADATE H, KIKUTA K, AOMURA S, KAKUTA A. Uniaxial stretch-induced axonal injury thresholds for axonal dysfunction and disruption and strain rate effects on thresholds for mouse neuronal stem cells. ACTA ACUST UNITED AC 2017. [DOI: 10.1299/jbse.16-00598] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Evrim KURTOGLU
- Graduate School of System Design, Tokyo Metropolitan University
| | | | - Kazuhiro KIKUTA
- Graduate School of System Design, Tokyo Metropolitan University
| | - Shigeru AOMURA
- Graduate School of System Design, Tokyo Metropolitan University
| | - Akira KAKUTA
- Advanced Course of Mechanical and Computer Systems Engineering, Tokyo National College of Technology
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37
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Lucke-Wold BP, Phillips M, Turner RC, Logsdon AF, Smith KE, Huber JD, Rosen CL, Regele JD. Elucidating the role of compression waves and impact duration for generating mild traumatic brain injury in rats. Brain Inj 2017; 31:98-105. [PMID: 27880054 PMCID: PMC5247354 DOI: 10.1080/02699052.2016.1218547] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND In total, 3.8 million concussions occur each year in the US leading to acute functional deficits, but the underlying histopathologic changes that occur are relatively unknown. In order to improve understanding of acute injury mechanisms, appropriately designed pre-clinical models must be utilized. METHODS The clinical relevance of compression wave injury models revolves around the ability to produce consistent histopathologic deficits. Mild traumatic brain injuries activate similar neuroinflammatory cascades, cell death markers and increases in amyloid precursor protein in both humans and rodents. Humans, however, infrequently succumb to mild traumatic brain injuries and, therefore, the intensity and magnitude of impacts must be inferred. Understanding compression wave properties and mechanical loading could help link the histopathologic deficits seen in rodents to what might be happening in human brains following concussions. RESULTS While the concept of linking duration and intensity of impact to subsequent histopathologic deficits makes sense, numerical modelling of compression waves has not been performed in this context. In this interdisciplinary work, numerical simulations were performed to study the creation of compression waves in an experimental model. CONCLUSION This work was conducted in conjunction with a repetitive compression wave injury paradigm in rats in order to better understand how the wave generation correlates with histopathologic deficits.
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Affiliation(s)
- Brandon P Lucke-Wold
- a Department of Neurosurgery
- b Center for Neuroscience, School of Medicine , West Virginia University , Morgantown , WV , USA
| | - Michael Phillips
- c Department of Aerospace Engineering , College of Engineering, Iowa State University , Ames , IA , USA
| | | | - Aric F Logsdon
- b Center for Neuroscience, School of Medicine , West Virginia University , Morgantown , WV , USA
- d Department of Pharmaceutical Sciences , School of Pharmacy, West Virginia University , Morgantown , WV , USA
| | - Kelly E Smith
- b Center for Neuroscience, School of Medicine , West Virginia University , Morgantown , WV , USA
- d Department of Pharmaceutical Sciences , School of Pharmacy, West Virginia University , Morgantown , WV , USA
| | - Jason D Huber
- d Department of Pharmaceutical Sciences , School of Pharmacy, West Virginia University , Morgantown , WV , USA
| | | | - Jonathan D Regele
- c Department of Aerospace Engineering , College of Engineering, Iowa State University , Ames , IA , USA
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38
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Yeh P, Guan Koay C, Wang B, Morissette J, Sham E, Senseney J, Joy D, Kubli A, Yeh C, Eskay V, Liu W, French LM, Oakes TR, Riedy G, Ollinger J. Compromised Neurocircuitry in Chronic Blast-Related Mild Traumatic Brain Injury. Hum Brain Mapp 2017; 38:352-369. [PMID: 27629984 PMCID: PMC6867097 DOI: 10.1002/hbm.23365] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 08/16/2016] [Accepted: 08/23/2016] [Indexed: 12/20/2022] Open
Abstract
The aim of this study was to apply recently developed automated fiber segmentation and quantification methods using diffusion tensor imaging (DTI) and DTI-based deterministic and probabilistic tractography to access local and global diffusion changes in blast-induced mild traumatic brain injury (bmTBI). Two hundred and two (202) male active US service members who reported persistent post-concussion symptoms for more than 6 months after injury were recruited. An additional forty (40) male military controls were included for comparison. DTI results were examined in relation to post-concussion and post-traumatic stress disorder (PTSD) symptoms. No significant group difference in DTI metrics was found using voxel-wise analysis. However, group comparison using tract profile analysis and tract specific analysis, as well as single subject analysis using tract profile analysis revealed the most prominent white matter microstructural injury in chronic bmTBI patients over the frontal fiber tracts, that is, the front-limbic projection fibers (cingulum bundle, uncinate fasciculus), the fronto-parieto-temporal association fibers (superior longitudinal fasciculus), and the fronto-striatal pathways (anterior thalamic radiation). Effects were noted to be sensitive to the number of previous blast exposures, with a negative association between fractional anisotropy (FA) and time since most severe blast exposure in a subset of the multiple blast-exposed group. However, these patterns were not observed in the subgroups classified using macrostructural changes (T2 white matter hyperintensities). Moreover, post-concussion symptoms and PTSD symptoms, as well as neuropsychological function were associated with low FA in the major nodes of compromised neurocircuitry. Hum Brain Mapp 38:352-369, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Ping‐Hong Yeh
- Henry Jackson Foundation for the Advancement of Military MedicineRockledgeMaryland
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
| | - Cheng Guan Koay
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
| | - Binquan Wang
- Henry Jackson Foundation for the Advancement of Military MedicineRockledgeMaryland
| | - John Morissette
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
| | - Elyssa Sham
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
| | - Justin Senseney
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
| | - David Joy
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
| | - Alex Kubli
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
| | - Chen‐Haur Yeh
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
| | - Victora Eskay
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
| | - Wei Liu
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
| | - Louis M. French
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
- Center for Neuroscience and Regenerative Medicine (CNRM)Uniformed Services University of the Health Sciences (USUHS)BethesdaMaryland
| | - Terrence R. Oakes
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
| | - Gerard Riedy
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
- Center for Neuroscience and Regenerative Medicine (CNRM)Uniformed Services University of the Health Sciences (USUHS)BethesdaMaryland
| | - John Ollinger
- National Intrepid Center of Excellence (NICoE)Walter Reed National Military Medical CenterBethesdaMaryland
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39
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Feng K, Zhang L, Jin X, Chen C, Kallakuri S, Saif T, Cavanaugh J, King A. Biomechanical Responses of the Brain in Swine Subject to Free-Field Blasts. Front Neurol 2016; 7:179. [PMID: 27822197 PMCID: PMC5075707 DOI: 10.3389/fneur.2016.00179] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 10/04/2016] [Indexed: 01/05/2023] Open
Abstract
Blast-induced traumatic brain injury (bTBI) is a signature wound of modern warfare. The current incomplete understanding of its injury mechanism impedes the development of strategies for effective protection of bTBI. Despite a considerable amount of experimental animal studies focused on the evaluation of brain neurotrauma caused by blast exposure, there is very limited knowledge on the biomechanical responses of the gyrenecephalic brain subjected to primary free-field blast waves imposed in vivo. This study aims to evaluate the external and internal mechanical responses of the brain against different levels of blast loading with Yucatan swine in free field. The incident overpressure (IOP) was generated using 3.6 kg of C4 charge placed at three standoff distances from the swine. Five swine were exposed to a total of 19 blasts. The three average peak IOP pressure levels in this study were 148.8, 278.9, and 409.2 kPa as measured by a pencil probe. The duration of the first positive wave was in the range of 2.1–3 ms. Pressure changes in the brain and head kinematics were recorded with intracranial pressure (ICP) sensors, linear accelerometers, and angular rate sensors. The corresponding average peak ICPs were in the range of 79–143, 210–281, and 311–414 kPa designated as low, medium, and high blast level, respectively. Peak head linear accelerations were in the range of 120–412 g. A positive correlation between IOP and its corresponding biomechanical responses of the brain was also observed. These experimental data can be used to validate computer models of bTBI.
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Affiliation(s)
- Ke Feng
- Department of Biomedical Engineering, Wayne State University , Detroit, MI , USA
| | - Liying Zhang
- Department of Biomedical Engineering, Wayne State University , Detroit, MI , USA
| | - Xin Jin
- Department of Biomedical Engineering, Wayne State University , Detroit, MI , USA
| | - Chaoyang Chen
- Department of Biomedical Engineering, Wayne State University , Detroit, MI , USA
| | - Srinivasu Kallakuri
- Department of Biomedical Engineering, Wayne State University , Detroit, MI , USA
| | - Tal Saif
- Department of Biomedical Engineering, Wayne State University , Detroit, MI , USA
| | - John Cavanaugh
- Department of Biomedical Engineering, Wayne State University , Detroit, MI , USA
| | - Albert King
- Department of Biomedical Engineering, Wayne State University , Detroit, MI , USA
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Bu W, Ren H, Deng Y, Del Mar N, Guley NM, Moore BM, Honig MG, Reiner A. Mild Traumatic Brain Injury Produces Neuron Loss That Can Be Rescued by Modulating Microglial Activation Using a CB2 Receptor Inverse Agonist. Front Neurosci 2016; 10:449. [PMID: 27766068 PMCID: PMC5052277 DOI: 10.3389/fnins.2016.00449] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 09/20/2016] [Indexed: 12/12/2022] Open
Abstract
We have previously reported that mild TBI created by focal left-side cranial blast in mice produces widespread axonal injury, microglial activation, and a variety of functional deficits. We have also shown that these functional deficits are reduced by targeting microglia through their cannabinoid type-2 (CB2) receptors using 2-week daily administration of the CB2 inverse agonist SMM-189. CB2 inverse agonists stabilize the G-protein coupled CB2 receptor in an inactive conformation, leading to increased phosphorylation and nuclear translocation of the cAMP response element binding protein (CREB), and thus bias activated microglia from a pro-inflammatory M1 to a pro-healing M2 state. In the present study, we showed that SMM-189 boosts nuclear pCREB levels in microglia in several brain regions by 3 days after TBI, by using pCREB/CD68 double immunofluorescent labeling. Next, to better understand the basis of motor deficits and increased fearfulness after TBI, we used unbiased stereological methods to characterize neuronal loss in cortex, striatum, and basolateral amygdala (BLA) and assessed how neuronal loss was affected by SMM-189 treatment. Our stereological neuron counts revealed a 20% reduction in cortical and 30% reduction in striatal neurons bilaterally at 2-3 months post blast, with SMM-189 yielding about 50% rescue. Loss of BLA neurons was restricted to the blast side, with 33% of Thy1+ fear-suppressing pyramidal neurons and 47% of fear-suppressing parvalbuminergic (PARV) interneurons lost, and Thy1-negative fear-promoting pyramidal neurons not significantly affected. SMM-189 yielded 50-60% rescue of Thy1+ and PARV neuron loss in BLA. Thus, fearfulness after mild TBI may result from the loss of fear-suppressing neuron types in BLA, and SMM-189 may reduce fearfulness by their rescue. Overall, our findings indicate that SMM-189 rescues damaged neurons and thereby alleviates functional deficits resulting from TBI, apparently by selectively modulating microglia to the beneficial M2 state. CB2 inverse agonists thus represent a promising therapeutic approach for mitigating neuroinflammation and neurodegeneration.
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Affiliation(s)
- Wei Bu
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center Memphis, TN, USA
| | - Huiling Ren
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center Memphis, TN, USA
| | - Yunping Deng
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center Memphis, TN, USA
| | - Nobel Del Mar
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center Memphis, TN, USA
| | - Natalie M Guley
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center Memphis, TN, USA
| | - Bob M Moore
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center Memphis, TN, USA
| | - Marcia G Honig
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center Memphis, TN, USA
| | - Anton Reiner
- Department of Anatomy and Neurobiology, University of Tennessee Health Science CenterMemphis, TN, USA; Department of Ophthalmology, University of Tennessee Health Science CenterMemphis, TN, USA
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Shively SB, Horkayne-Szakaly I, Jones RV, Kelly JP, Armstrong RC, Perl DP. Characterisation of interface astroglial scarring in the human brain after blast exposure: a post-mortem case series. Lancet Neurol 2016; 15:944-953. [DOI: 10.1016/s1474-4422(16)30057-6] [Citation(s) in RCA: 129] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 04/07/2016] [Accepted: 04/18/2016] [Indexed: 01/23/2023]
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Dorsett CR, McGuire JL, DePasquale EAK, Gardner AE, Floyd CL, McCullumsmith RE. Glutamate Neurotransmission in Rodent Models of Traumatic Brain Injury. J Neurotrauma 2016; 34:263-272. [PMID: 27256113 DOI: 10.1089/neu.2015.4373] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Traumatic brain injury (TBI) is a leading cause of death and disability in people younger than 45 and is a significant public health concern. In addition to primary mechanical damage to cells and tissue, TBI involves additional molecular mechanisms of injury, termed secondary injury, that continue to evolve over hours, days, weeks, and beyond. The trajectory of recovery after TBI is highly unpredictable and in many cases results in chronic cognitive and behavioral changes. Acutely after TBI, there is an unregulated release of glutamate that cannot be buffered or cleared effectively, resulting in damaging levels of glutamate in the extracellular space. This initial loss of glutamate homeostasis may initiate additional changes in glutamate regulation. The excitatory amino acid transporters (EAATs) are expressed on both neurons and glia and are the principal mechanism for maintaining extracellular glutamate levels. Diffusion of glutamate outside the synapse due to impaired uptake may lead to increased extrasynaptic glutamate signaling, secondary injury through activation of cell death pathways, and loss of fidelity and specificity of synaptic transmission. Coordination of glutamate release and uptake is critical to regulating synaptic strength, long-term potentiation and depression, and cognitive processes. In this review, we will discuss dysregulation of extracellular glutamate and glutamate uptake in the acute stage of TBI and how failure to resolve acute disruptions in glutamate homeostatic mechanisms may play a causal role in chronic cognitive symptoms after TBI.
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Affiliation(s)
- Christopher R Dorsett
- 1 Biological and Biomedical Sciences Doctoral Program, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
| | - Jennifer L McGuire
- 2 Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati , Cincinnati, Ohio
| | - Erica A K DePasquale
- 2 Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati , Cincinnati, Ohio
| | - Amanda E Gardner
- 2 Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati , Cincinnati, Ohio
| | - Candace L Floyd
- 3 Department of Physical Medicine and Rehabilitation, University of Alabama at Birmingham , Birmingham, Alabama
| | - Robert E McCullumsmith
- 2 Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati , Cincinnati, Ohio
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Carron SF, Yan EB, Alwis DS, Rajan R. Differential susceptibility of cortical and subcortical inhibitory neurons and astrocytes in the long term following diffuse traumatic brain injury. J Comp Neurol 2016; 524:3530-3560. [PMID: 27072754 DOI: 10.1002/cne.24014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2015] [Revised: 04/01/2016] [Accepted: 04/04/2016] [Indexed: 02/02/2023]
Abstract
Long-term diffuse traumatic brain injury (dTBI) causes neuronal hyperexcitation in supragranular layers in sensory cortex, likely through reduced inhibition. Other forms of TBI affect inhibitory interneurons in subcortical areas but it is unknown if this occurs in cortex, or in any brain area in dTBI. We investigated dTBI effects on inhibitory neurons and astrocytes in somatosensory and motor cortex, and hippocampus, 8 weeks post-TBI. Brains were labeled with antibodies against calbindin (CB), parvalbumin (PV), calretinin (CR) and neuropeptide Y (NPY), and somatostatin (SOM) and glial fibrillary acidic protein (GFAP), a marker for astrogliosis during neurodegeneration. Despite persistent behavioral deficits in rotarod performance up to the time of brain extraction (TBI = 73.13 ± 5.23% mean ± SEM, Sham = 92.29 ± 5.56%, P < 0.01), motor cortex showed only a significant increase, in NPY neurons in supragranular layers (mean cells/mm2 ± SEM, Sham = 16 ± 0.971, TBI = 25 ± 1.51, P = 0.001). In somatosensory cortex, only CR+ neurons showed changes, being decreased in supragranular (TBI = 19 ± 1.18, Sham = 25 ± 1.10, P < 0.01) and increased in infragranular (TBI = 28 ± 1.35, Sham = 24 ± 1.07, P < 0.05) layers. Heterogeneous changes were seen in hippocampal staining: CB+ decreased in dentate gyrus (TBI = 2 ± 0.382, Sham = 4 ± 0.383, P < 0.01), PV+ increased in CA1 (TBI = 39 ± 1.26, Sham = 33 ± 1.69, P < 0.05) and CA2/3 (TBI = 26 ± 2.10, Sham = 20 ± 1.49, P < 0.05), and CR+ decreased in CA1 (TBI = 10 ± 1.02, Sham = 14 ± 1.14, P < 0.05). Astrogliosis significantly increased in corpus callosum (TBI = 6.7 ± 0.69, Sham = 2.5 ± 0.38; P = 0.007). While dTBI effects on inhibitory neurons appear region- and type-specific, a common feature in all cases of decrease was that changes occurred in dendrite targeting interneurons involved in neuronal integration. J. Comp. Neurol. 524:3530-3560, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Simone F Carron
- Department of Physiology, Monash University, Melbourne, VIC, Australia
| | - Edwin B Yan
- Department of Physiology, Monash University, Melbourne, VIC, Australia
| | - Dasuni S Alwis
- Department of Physiology, Monash University, Melbourne, VIC, Australia
| | - Ramesh Rajan
- Department of Physiology, Monash University, Melbourne, VIC, Australia.
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Dura-Bernal S, Li K, Neymotin SA, Francis JT, Principe JC, Lytton WW. Restoring Behavior via Inverse Neurocontroller in a Lesioned Cortical Spiking Model Driving a Virtual Arm. Front Neurosci 2016; 10:28. [PMID: 26903796 PMCID: PMC4746359 DOI: 10.3389/fnins.2016.00028] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 01/25/2016] [Indexed: 01/08/2023] Open
Abstract
Neural stimulation can be used as a tool to elicit natural sensations or behaviors by modulating neural activity. This can be potentially used to mitigate the damage of brain lesions or neural disorders. However, in order to obtain the optimal stimulation sequences, it is necessary to develop neural control methods, for example by constructing an inverse model of the target system. For real brains, this can be very challenging, and often unfeasible, as it requires repeatedly stimulating the neural system to obtain enough probing data, and depends on an unwarranted assumption of stationarity. By contrast, detailed brain simulations may provide an alternative testbed for understanding the interactions between ongoing neural activity and external stimulation. Unlike real brains, the artificial system can be probed extensively and precisely, and detailed output information is readily available. Here we employed a spiking network model of sensorimotor cortex trained to drive a realistic virtual musculoskeletal arm to reach a target. The network was then perturbed, in order to simulate a lesion, by either silencing neurons or removing synaptic connections. All lesions led to significant behvaioral impairments during the reaching task. The remaining cells were then systematically probed with a set of single and multiple-cell stimulations, and results were used to build an inverse model of the neural system. The inverse model was constructed using a kernel adaptive filtering method, and was used to predict the neural stimulation pattern required to recover the pre-lesion neural activity. Applying the derived neurostimulation to the lesioned network improved the reaching behavior performance. This work proposes a novel neurocontrol method, and provides theoretical groundwork on the use biomimetic brain models to develop and evaluate neurocontrollers that restore the function of damaged brain regions and the corresponding motor behaviors.
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Affiliation(s)
- Salvador Dura-Bernal
- Department of Physiology and Pharmacology, State University of New York Downstate Medical Center Brooklyn, NY, USA
| | - Kan Li
- Department of Electrical and Computer Engineering, University of Florida Gainesville, FL, USA
| | - Samuel A Neymotin
- Department of Physiology and Pharmacology, State University of New York Downstate Medical Center Brooklyn, NY, USA
| | - Joseph T Francis
- Department of Physiology and Pharmacology, State University of New York Downstate Medical CenterBrooklyn, NY, USA; BME Cullen College of Engineering, University of HoustonHouston, TX, USA
| | - Jose C Principe
- Department of Electrical and Computer Engineering, University of Florida Gainesville, FL, USA
| | - William W Lytton
- Department of Physiology and Pharmacology, State University of New York Downstate Medical CenterBrooklyn, NY, USA; Department of Neurology, State University of New York Downstate Medical CenterBrooklyn, NY, USA; Department of Neurology, Kings County Hospital CenterBrooklyn, NY, USA
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45
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Tasissa AF, Hautefeuille M, Fitek JH, Radovitzky RA. On the formation of Friedlander waves in a compressed-gas-driven shock tube. Proc Math Phys Eng Sci 2016; 472:20150611. [PMID: 27118888 DOI: 10.1098/rspa.2015.0611] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Compressed-gas-driven shock tubes have become popular as a laboratory-scale replacement for field blast tests. The well-known initial structure of the Riemann problem eventually evolves into a shock structure thought to resemble a Friedlander wave, although this remains to be demonstrated theoretically. In this paper, we develop a semi-analytical model to predict the key characteristics of pseudo blast waves forming in a shock tube: location where the wave first forms, peak over-pressure, decay time and impulse. The approach is based on combining the solutions of the two different types of wave interactions that arise in the shock tube after the family of rarefaction waves in the Riemann solution interacts with the closed end of the tube. The results of the analytical model are verified against numerical simulations obtained with a finite volume method. The model furnishes a rational approach to relate shock tube parameters to desired blast wave characteristics, and thus constitutes a useful tool for the design of shock tubes for blast testing.
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Affiliation(s)
- Abiy F Tasissa
- Institute for Solider Nanotechnologies , Department of Aeronautics and Astronautics, Massachusetts Institute of Technology , Cambridge, MA 02139, USA
| | - Martin Hautefeuille
- Institute for Solider Nanotechnologies , Department of Aeronautics and Astronautics, Massachusetts Institute of Technology , Cambridge, MA 02139, USA
| | - John H Fitek
- US Army Natick Soldier Research , Development and Engineering Center , Natick, MA 01760, USA
| | - Raúl A Radovitzky
- Institute for Solider Nanotechnologies , Department of Aeronautics and Astronautics, Massachusetts Institute of Technology , Cambridge, MA 02139, USA
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46
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Przekwas A, Somayaji MR, Gupta RK. Synaptic Mechanisms of Blast-Induced Brain Injury. Front Neurol 2016; 7:2. [PMID: 26834697 PMCID: PMC4720734 DOI: 10.3389/fneur.2016.00002] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 01/04/2016] [Indexed: 01/08/2023] Open
Abstract
Blast wave-induced traumatic brain injury (TBI) is one of the most common injuries to military personnel. Brain tissue compression/tension due to blast-induced cranial deformations and shear waves due to head rotation may generate diffuse micro-damage to neuro-axonal structures and trigger a cascade of neurobiological events culminating in cognitive and neurodegenerative disorders. Although diffuse axonal injury is regarded as a signature wound of mild TBI (mTBI), blast loads may also cause synaptic injury wherein neuronal synapses are stretched and sheared. This synaptic injury may result in temporary disconnect of the neural circuitry and transient loss in neuronal communication. We hypothesize that mTBI symptoms such as loss of consciousness or dizziness, which start immediately after the insult, could be attributed to synaptic injury. Although empirical evidence is beginning to emerge; the detailed mechanisms underlying synaptic injury are still elusive. Coordinated in vitro-in vivo experiments and mathematical modeling studies can shed light into the synaptic injury mechanisms and their role in the potentiation of mTBI symptoms.
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Affiliation(s)
- Andrzej Przekwas
- Computational Medicine and Biology Division, CFD Research Corporation, Huntsville, AL, USA
| | | | - Raj K. Gupta
- Department of Defense Blast Injury Research Program Coordinating Office, U.S. Army Medical Research and Materiel Command, Fort Detrick, MD, USA
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Sliozberg Y, Chantawansri T. Damage in spherical cellular membrane generated by the shock waves: coarse-grained molecular dynamics simulation of lipid vesicle. J Chem Phys 2015; 141:184904. [PMID: 25399159 DOI: 10.1063/1.4901130] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Traumatic Brain Injury is a major health issue that is hard to diagnose since it often occurs without signs of external injuries. While it is well known that exposure of biological cells to shock waves causes damage to the cell membrane, it is currently unknown by which mechanisms damage is caused, and how it depends on physical parameters such as shock wave velocity, shock pulse duration, or shock pulse shape. In this computational study, we use a coarse-grained model of the lipid vesicle as a generic model of a cell membrane to elucidate the general principles of the cellular damage induced by the shock wave direct passage through the cranium. Results indicate that the extent of the liposome compression does not strongly depend on the pressure pulse and that liposome extension is very sensitive to the change in the negative pressure phase. The structural integrity of the vesicle is altered as pores form in the lipid membrane at overall pressure impulses generated by supersonic shock waves, which are greater than 5 Pa·s at single or repetitive exposure. Consequently, these permeability changes may lead to changes in the influx of sodium, potassium, and calcium ions.
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Affiliation(s)
- Yelena Sliozberg
- TKC Global at U.S. Army Research Laboratory, 4600 Deer Creek Loop, Aberdeen Proving Ground, Maryland 21005-5069, USA
| | - Tanya Chantawansri
- U.S. Army Research Laboratory, 4600 Deer Creek Loop, Aberdeen Proving Ground, Maryland 21005-5069, USA
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Goriely A, Geers MGD, Holzapfel GA, Jayamohan J, Jérusalem A, Sivaloganathan S, Squier W, van Dommelen JAW, Waters S, Kuhl E. Mechanics of the brain: perspectives, challenges, and opportunities. Biomech Model Mechanobiol 2015; 14:931-65. [PMID: 25716305 PMCID: PMC4562999 DOI: 10.1007/s10237-015-0662-4] [Citation(s) in RCA: 181] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Accepted: 02/14/2015] [Indexed: 12/24/2022]
Abstract
The human brain is the continuous subject of extensive investigation aimed at understanding its behavior and function. Despite a clear evidence that mechanical factors play an important role in regulating brain activity, current research efforts focus mainly on the biochemical or electrophysiological activity of the brain. Here, we show that classical mechanical concepts including deformations, stretch, strain, strain rate, pressure, and stress play a crucial role in modulating both brain form and brain function. This opinion piece synthesizes expertise in applied mathematics, solid and fluid mechanics, biomechanics, experimentation, material sciences, neuropathology, and neurosurgery to address today’s open questions at the forefront of neuromechanics. We critically review the current literature and discuss challenges related to neurodevelopment, cerebral edema, lissencephaly, polymicrogyria, hydrocephaly, craniectomy, spinal cord injury, tumor growth, traumatic brain injury, and shaken baby syndrome. The multi-disciplinary analysis of these various phenomena and pathologies presents new opportunities and suggests that mechanical modeling is a central tool to bridge the scales by synthesizing information from the molecular via the cellular and tissue all the way to the organ level.
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Affiliation(s)
- Alain Goriely
- Mathematical Institute, University of Oxford, Oxford, OX2 6GG, UK,
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Newman AJ, Hayes SH, Rao AS, Allman BL, Manohar S, Ding D, Stolzberg D, Lobarinas E, Mollendorf JC, Salvi R. Low-cost blast wave generator for studies of hearing loss and brain injury: blast wave effects in closed spaces. J Neurosci Methods 2015; 242:82-92. [PMID: 25597910 DOI: 10.1016/j.jneumeth.2015.01.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 12/12/2014] [Accepted: 01/07/2015] [Indexed: 01/24/2023]
Abstract
BACKGROUND Military personnel and civilians living in areas of armed conflict have increased risk of exposure to blast overpressures that can cause significant hearing loss and/or brain injury. The equipment used to simulate comparable blast overpressures in animal models within laboratory settings is typically very large and prohibitively expensive. NEW METHOD To overcome the fiscal and space limitations introduced by previously reported blast wave generators, we developed a compact, low-cost blast wave generator to investigate the effects of blast exposures on the auditory system and brain. RESULTS The blast wave generator was constructed largely from off the shelf components, and reliably produced blasts with peak sound pressures of up to 198dB SPL (159.3kPa) that were qualitatively similar to those produced from muzzle blasts or explosions. Exposure of adult rats to 3 blasts of 188dB peak SPL (50.4kPa) resulted in significant loss of cochlear hair cells, reduced outer hair cell function and a decrease in neurogenesis in the hippocampus. COMPARISON TO EXISTING METHODS Existing blast wave generators are typically large, expensive, and are not commercially available. The blast wave generator reported here provides a low-cost method of generating blast waves in a typical laboratory setting. CONCLUSIONS This compact blast wave generator provides scientists with a low cost device for investigating the biological mechanisms involved in blast wave injury to the rodent cochlea and brain that may model many of the damaging effects sustained by military personnel and civilians exposed to intense blasts.
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Affiliation(s)
- Andrew J Newman
- Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, NY, United States.
| | - Sarah H Hayes
- Center for Hearing & Deafness, Department of Communicative Disorders and Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States.
| | - Abhiram S Rao
- Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, NY, United States.
| | - Brian L Allman
- Center for Hearing & Deafness, Department of Communicative Disorders and Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States.
| | - Senthilvelan Manohar
- Center for Hearing & Deafness, Department of Communicative Disorders and Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States.
| | - Dalian Ding
- Center for Hearing & Deafness, Department of Communicative Disorders and Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States.
| | - Daniel Stolzberg
- Center for Hearing & Deafness, Department of Communicative Disorders and Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States.
| | - Edward Lobarinas
- Center for Hearing & Deafness, Department of Communicative Disorders and Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States.
| | - Joseph C Mollendorf
- Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, NY, United States.
| | - Richard Salvi
- Center for Hearing & Deafness, Department of Communicative Disorders and Sciences, University at Buffalo, The State University of New York, Buffalo, NY, United States.
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50
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Elder GA, Stone JR, Ahlers ST. Effects of low-level blast exposure on the nervous system: is there really a controversy? Front Neurol 2014; 5:269. [PMID: 25566175 PMCID: PMC4271615 DOI: 10.3389/fneur.2014.00269] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 11/29/2014] [Indexed: 12/20/2022] Open
Abstract
High-pressure blast waves can cause extensive CNS injury in human beings. However, in combat settings, such as Iraq and Afghanistan, lower level exposures associated with mild traumatic brain injury (mTBI) or subclinical exposure have been much more common. Yet controversy exists concerning what traits can be attributed to low-level blast, in large part due to the difficulty of distinguishing blast-related mTBI from post-traumatic stress disorder (PTSD). We describe how TBI is defined in human beings and the problems posed in using current definitions to recognize blast-related mTBI. We next consider the problem of applying definitions of human mTBI to animal models, in particular that TBI severity in human beings is defined in relation to alteration of consciousness at the time of injury, which typically cannot be assessed in animals. However, based on outcome assessments, a condition of "low-level" blast exposure can be defined in animals that likely approximates human mTBI or subclinical exposure. We review blast injury modeling in animals noting that inconsistencies in experimental approach have contributed to uncertainty over the effects of low-level blast. Yet, animal studies show that low-level blast pressure waves are transmitted to the brain. In brain, low-level blast exposures cause behavioral, biochemical, pathological, and physiological effects on the nervous system including the induction of PTSD-related behavioral traits in the absence of a psychological stressor. We review the relationship of blast exposure to chronic neurodegenerative diseases noting the paradoxical lowering of Abeta by blast, which along with other observations suggest that blast-related TBI is pathophysiologically distinct from non-blast TBI. Human neuroimaging studies show that blast-related mTBI is associated with a variety of chronic effects that are unlikely to be explained by co-morbid PTSD. We conclude that abundant evidence supports low-level blast as having long-term effects on the nervous system.
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Affiliation(s)
- Gregory A. Elder
- Neurology Service, James J. Peters Department of Veterans Affairs Medical Center, Bronx, NY, USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - James R. Stone
- Department of Radiology, University of Virginia, Charlottesville, VA, USA
- Department of Neurosurgery, University of Virginia, Charlottesville, VA, USA
| | - Stephen T. Ahlers
- Department of Neurotrauma, Operational and Undersea Medicine Directorate, Naval Medical Research Center, Silver Spring, MD, USA
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