Blast Traumatic Brain Injury Mechanisms

Blast traumatic brain injury (bTBI) is a leading cause of head injury in soldiers returning from the battlefield. Primary blast brain injury remains controversial with little evidence to support a primary mechanism of injury. The four main theories described herein include blast wave transmission through skull orifices, direct cranial transmission, thoracic surge, and skull flexure dynamics. It is possible that these mechanisms do not occur exclusively from each other, but rather that several of them lead to primary blast brain injury. Biomechanical investigation with in-vivo, cadaver, and finite element models would greatly increase our understanding of bTBI mechanisms.

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Primary Blast Brain Injury Mechanisms: Current Knowledge, Limitations, and Future Directions

Journal of Biomechanical Engineering ◽

10.1115/1.4038710 ◽

2018 ◽

Vol 140 (2) ◽

Cited By ~ 14

Author(s):

Elizabeth Fievisohn ◽

Zachary Bailey ◽

Allison Guettler ◽

Pamela VandeVord

Keyword(s):

Brain Injury ◽

Current Knowledge ◽

Future Research ◽

Primary Blast ◽

Injury Criteria ◽

Blast Traumatic Brain Injury ◽

Injury Mechanisms ◽

Combination Of Theories ◽

Injury Research

Mild blast traumatic brain injury (bTBI) accounts for the majority of brain injury in United States service members and other military personnel worldwide. The mechanisms of primary blast brain injury continue to be disputed with little evidence to support one or a combination of theories. The main hypotheses addressed in this review are blast wave transmission through the skull orifices, direct cranial transmission, skull flexure dynamics, thoracic surge, acceleration, and cavitation. Each possible mechanism is discussed using available literature with the goal of focusing research efforts to address the limitations and challenges that exist in blast injury research. Multiple mechanisms may contribute to the pathology of bTBI and could be dependent on magnitudes and orientation to blast exposure. Further focused biomechanical investigation with cadaver, in vivo, and finite element models would advance our knowledge of bTBI mechanisms. In addition, this understanding could guide future research and contribute to the greater goal of developing relevant injury criteria and mandates to protect our soldiers on the battlefield.

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Embedded axonal fiber tracts improve finite element model predictions of traumatic brain injury

Biomechanics and Modeling in Mechanobiology ◽

10.1007/s10237-019-01273-8 ◽

2019 ◽

Vol 19 (3) ◽

pp. 1109-1130 ◽

Cited By ~ 3

Author(s):

Marzieh Hajiaghamemar ◽

Taotao Wu ◽

Matthew B. Panzer ◽

Susan S. Margulies

Keyword(s):

Traumatic Brain Injury ◽

Finite Element ◽

Brain Injury ◽

Strain Rate ◽

Brain Tissue ◽

Brain Injuries ◽

Characteristic Curve ◽

Strain And Strain Rate

AbstractWith the growing rate of traumatic brain injury (TBI), there is an increasing interest in validated tools to predict and prevent brain injuries. Finite element models (FEM) are valuable tools to estimate tissue responses, predict probability of TBI, and guide the development of safety equipment. In this study, we developed and validated an anisotropic pig brain multi-scale FEM by explicitly embedding the axonal tract structures and utilized the model to simulate experimental TBI in piglets undergoing dynamic head rotations. Binary logistic regression, survival analysis with Weibull distribution, and receiver operating characteristic curve analysis, coupled with repeated k-fold cross-validation technique, were used to examine 12 FEM-derived metrics related to axonal/brain tissue strain and strain rate for predicting the presence or absence of traumatic axonal injury (TAI). All 12 metrics performed well in predicting of TAI with prediction accuracy rate of 73–90%. The axonal-based metrics outperformed their rival brain tissue-based metrics in predicting TAI. The best predictors of TAI were maximum axonal strain times strain rate (MASxSR) and its corresponding optimal fraction-based metric (AF-MASxSR7.5) that represents the fraction of axonal fibers exceeding MASxSR of 7.5 s−1. The thresholds compare favorably with tissue tolerances found in in–vitro/in–vivo measurements in the literature. In addition, the damaged volume fractions (DVF) predicted using the axonal-based metrics, especially MASxSR (DVF = 0.05–4.5%), were closer to the actual DVF obtained from histopathology (AIV = 0.02–1.65%) in comparison with the DVF predicted using the brain-related metrics (DVF = 0.11–41.2%). The methods and the results from this study can be used to improve model prediction of TBI in humans.

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Primary Blast-induced Traumatic Brain Injury : Current Understandings and Translational Research(Traumatic Head Injury Update)

Japanese Journal of Neurosurgery ◽

10.7887/jcns.20.896 ◽

2011 ◽

Vol 20 (12) ◽

pp. 896-902

Author(s):

Atsuhiro Nakagawa ◽

Teiji Tominaga

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

Head Injury ◽

Translational Research ◽

Special Issue ◽

Traumatic Head Injury ◽

Primary Blast ◽

Traumatic Head

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An Experimental Study of Blast Traumatic Brain Injury

ASME 2008 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2008-192338 ◽

2008 ◽

Author(s):

Jiangyue Zhang ◽

Narayan Yoganandan ◽

Frank A. Pintar ◽

Steven F. Son ◽

Thomas A. Gennarelli

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

Armed Forces ◽

Head Model ◽

Trauma Studies ◽

Injury Biomechanics ◽

Blast Traumatic Brain Injury ◽

Injury Mechanisms ◽

Explosive Devices ◽

Complicated Nature

Traumatic brain injury from explosive devices has become the signature wound of the U.S. armed forces in Iraq and Afghanistan [1–4]. However, due to the complicated nature of this specific form of brain injury, little is known about the injury mechanisms. Physical head models have been used in blunt and penetrating head trauma studies to obtain biomechanical data and correlate to mechanisms of injury [5–8]. The current study is designed to investigate intracranial head/brain injury biomechanics under blast loading using a physical head model.

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SOME CONSIDERATIONS ON THE THRESHOLD AND INTER-SPECIES SCALING LAW FOR PRIMARY BLAST-INDUCED TRAUMATIC BRAIN INJURY: A SEMI-ANALYTICAL APPROACH

Journal of Mechanics in Medicine and Biology ◽

10.1142/s0219519413500656 ◽

2013 ◽

Vol 13 (04) ◽

pp. 1350065 ◽

Cited By ~ 7

Author(s):

FENG ZHU ◽

CLIFF C. CHOU ◽

KING H. YANG ◽

ALBERT I. KING

Keyword(s):

Traumatic Brain Injury ◽

Brain Injury ◽

Injury Risk ◽

Scaling Law ◽

Protective Equipment ◽

Primary Blast ◽

Injury Mechanisms ◽

Military Conflicts ◽

Risk Curve ◽

Risk Curves

Blast-induced traumatic brain injury (bTBI) has become a signature injury in recent military conflicts and terrorist attacks. However, the mechanisms and thresholds for such injury are still unknown. In this paper, effort has been made toward establishing the threshold due to primary blast based on the published injury data in the rat. Peak incident overpressure and pulse duration of the incident wave were used as predictors and the injury risk curves for the rat were derived via a linear logistic regression analysis. A scaling law based on body mass was then used to scale the tolerance curves from the rat to the pig and the human. The injury risk curve for bTBI was compared with that for the lung. The results reveal different injury mechanisms between these two organs. The developed injury curves can be used in the design of personal protective equipment against primary bTBI.

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