Biomechanics Injury Analysis of Brain White Matter Using Cohesive Zone Method

2009 ◽  
Author(s):  
N. Abolfathi ◽  
A. R. Syed ◽  
G. Karami ◽  
M. Ziejewski
Keyword(s):  
White Matter ◽  
Brain Tissue ◽  
Cohesive Zone ◽  
Axonal Injury ◽  
Diffuse Axonal Injury ◽  
Severe Disabilities ◽  
Cohesive Zone Modeling ◽  
Zone Method ◽  
Brain White Matter ◽  
The Impact

Diffuse Axonal Injury (DAI) can happen due to sudden motion of the head and loading and is a major cause of fatality and severe disabilities. This injury can be biomechanically translated in terms of change in axon geometry and its separation and distortion from the surrounding cells and the extra cellular matrix (ECM). To study DAI, a microscale biomechanical modeling of tissue is forwarded. This modeling benefits from the studies on fibrous composite modeling procedure to examine the tissue and the fibrous axonal injury. Employing a developed micromechanics failure analysis for fibrous composites, the white mater of the brain is assumed as the composite with axon as the fiber and ECM as the matrix. The focus here is on the interface and adhesion of the axon and ECM on the material characteristics of the tissue. The cohesive zone modeling (CZM) is employed to model the interface. The impact due to interface is studied in detail on the characteristics of the white matter tissue. This modeling method enhances the previously proposed micromechanics modeling of brain tissue and enable one to predict the impact due to sliding, and separation of the axons and ECM on the load transfer, stress and strain distribution of axon, ECM and tissue for a microstructural examination of DAI and tissue failure. This can improve the understanding of injury from mechanical perspective and help in detail predicting of any injuries in cellular level in brain tissue.

Diffuse Axonal Injury and Degradation in Mechanical Characteristics of Brain White Matter

2008 ◽  
Author(s):  
Nabi Abolfathi ◽  
Abhai Naik ◽  
Mahdi Sotudeh ◽  
Ghodrat Karami ◽  
Mariusz Ziejewski
Keyword(s):  
Brain Tissue ◽  
Fibrous Composite ◽  
Axonal Injury ◽  
Diffuse Axonal Injury ◽  
Viscoelastic Behavior ◽  
Severe Disabilities ◽  
Post Injury ◽  
Brain White Matter ◽  
Injured Brain

Diffuse Axonal Injury (DAI) can happen due to sudden motions of head and is one of the major causes of fatality and severe disabilities. To study DAI, any change in material characteristics of brain tissue post injury needs to be well understood. In this study, the focus will be on changes in the viscoelastic material properties of white mater in the brain due to DAI resulting in axonal disconnections. Using a micromechanics fibrous composite modeling for white mater, we have developed an algorithm to analyze the effect of discontinuity due to breakage of axons inside the surrounded matrix. Repeated unit cell (RUC) was assumed to represent the axonal distribution within the extracellular matrix. Relaxation test were conducted for characterization of the viscoelastic behavior. The result of this study provides a modeling technique for characterization of injured brain tissue in white mater and proposes necessity of including the appropriate post injury axonal mechanical properties. These findings can improve the understanding of injury from mechanical perspective and help in predicting vulnerability of any such injured tissue against further injuries.

A study of the blast‐induced brain white‐matter damage and the associated diffuse axonal injury

2012 ◽  
Vol 8 (2) ◽  
pp. 213-245 ◽  
Author(s):  
M. Grujicic ◽  
B. d'Entremont ◽  
B. Pandurangan ◽  
A. Grujicic ◽  
M. LaBerge ◽  
...  
Keyword(s):  
White Matter ◽  
Axonal Injury ◽  
Diffuse Axonal Injury ◽  
White Matter Damage ◽  
Brain White Matter

Changes in Viscoelastic Properties of Brain Tissue Due to Traumatic Injury

2004 ◽  
Author(s):  
Kurosh Darvish ◽  
James Stone
Keyword(s):  
Brain Tissue ◽  
Material Properties ◽  
Computational Models ◽  
Axonal Injury ◽  
Traumatic Injury ◽  
Diffuse Axonal Injury ◽  
Elastic Response ◽  
Tissue Properties ◽  
The Impact ◽  
The Brain

In this study, changes in viscoelastic material properties of brain tissue due to traumatic axonal injury (TAI) were investigated. The impact acceleration model was used to generate diffuse axonal injury in rat brain. TAI in the corticospinal (CSpT) tract in the brain stem was quantified using amyloid precursor protein immunostaining. Material properties along the CSpT were determined using an indentation technique. The results showed that the number of injured axons at the pyramidal decussation (PDx) was approximated 10 times higher than in the ponto-medullary junction (PmJ). The instantaneous elastic response was reduced approximately 70% at PDx compared to 40% at PmJ and the relaxation was uniformly reduced approximately 30%, which were attributed to the effect of injury on tissue properties. Application of a visco-elastic-plastic model that changes due to TAI can significantly alter the results of computational models of brain injury.

Microstructural Hyperelastic Characterization of Brain White Matter in Tension

2019 ◽  
Author(s):  
Mohammadreza Ramzanpour ◽  
Mohammad Hosseini-Farid ◽  
Mariusz Ziejewski ◽  
Ghodrat Karami
Keyword(s):  
Finite Element ◽  
White Matter ◽  
Human Brain ◽  
Volume Fraction ◽  
Fibrous Composite ◽  
Diffuse Axonal Injury ◽  
Stiffness Ratio ◽  
Fibrous Composite Material ◽  
Brain White Matter ◽  
The Brain

Abstract Axons as microstructural constituent elements of brain white matter are highly oriented in extracellular matrix (ECM) in one direction. Therefore, it is possible to model the human brain white matter as a unidirectional fibrous composite material. A micromechanical finite element model of the brain white matter is developed to indirectly measure the brain white matter constituents’ properties including axon and ECM under tensile loading. Experimental tension test on corona radiata conducted by Budday et al. 2017 [1] is used in this study and one-term Ogden hyperelastic constitutive model is applied to characterize its behavior. By the application of genetic algorithm (GA) as a black box optimization method, the Ogden hyperelastic parameters of axon and ECM minimizing the error between numerical finite element simulation and experimental results are measured. Inverse analysis is conducted on the resultant optimized parameters shows high correlation of coefficient (>99%) between the numerical and experimental data which verifies the accuracy of the optimization procedure. The volume fraction of axons in porcine brain white matter is taken to be 52.7% and the stiffness ratio of axon to ECM is perceived to be 3.0. As these values are not accurately known for human brain white matter, we study the material properties of axon and ECM for different stiffness ratio and axon volume fraction values. The results of this study helps to better understand the micromechanical structure of the brain and micro-level injuries such as diffuse axonal injury.

scholarly journals A Conceptual Overview of Axonopathy in Infants and Children with Allegedly Inflicted Head Trauma

2016 ◽  
Vol 6 (4) ◽  
pp. 608-621
Author(s):  
Vivian S. Snyder ◽  
Lawrence A. Hansen
Keyword(s):  
White Matter ◽  
Head Trauma ◽  
Forensic Pathology ◽  
Axonal Injury ◽  
Diffuse Axonal Injury ◽  
Infants And Children ◽  
Post Injury ◽  
Controversial Topic ◽  
Definition Of ◽  
Medical Disciplines

Fatal, allegedly inflicted pediatric head trauma remains a controversial topic in forensic pathology. Recommendations for systematic neuropathologic evaluation of the brains of supposedly injured infants and children usually include the assessment of long white matter tracts in search of axonopathy — specifically, diffuse axonal injury. The ability to recognize, document, and interpret injuries to axons has significant academic and medicolegal implications. For example, more than two decades of inconsistent nosology have resulted in confusion about the definition of diffuse axonal injury between various medical disciplines including radiology, neurosurgery, pediatrics, neuropathology, and forensic pathology. Furthermore, in the pediatric setting, acceptance that “pure” shaking can cause axonal shearing in infants and young children is not widespread. Additionally, controversy abounds whether or not axonal trauma can be identified within regions of white matter ischemia — a debate with very significant implications. Immunohistochemistry is often used not only to document axonal injury, but also to estimate the time since injury. As a result, the estimated post-injury interval may then be used by law enforcement officers and prosecutors to narrow “exclusive opportunity” and thus, identify potential suspects. Fundamental to these highly complicated and controversial topics is a philosophical understanding of the diffuse axonal injury spectrum disorders.

281 Predicting neurodegeneration after traumatic brain injury

2018 ◽  
Vol 89 (10) ◽  
pp. A42.1-A42
Author(s):  
Graham Neil SN ◽  
Jolly Amy E ◽  
Bourke Niall J ◽  
Scott Gregory ◽  
Cole James H ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
White Matter ◽  
Brain Atrophy ◽  
Diffusion Tensor ◽  
Chronic Traumatic Encephalopathy ◽  
Axonal Injury ◽  
Diffuse Axonal Injury ◽  
Jacobian Determinant ◽  
Post Injury

BackgroundDementia rates are elevated after traumatic brain injury (TBI) and a subgroup develops chronic traumatic encephalopathy. Post-traumatic neurodegeneration can be measured by brain atrophy rates derived from neuroimaging, but it is unclear how atrophy relates to the initial pattern of injury.ObjectivesTo investigate the relationship between baseline TBI patterns and subsequent neurodegeneration measured by progressive brain atrophy.Methods55 patients after moderate-severe TBI (mean 3 years post-injury) and 20 controls underwent longitudinal MRI. Brain atrophy was quantified using the Jacobian determinant defined from volumetric T1 scans approximately one year apart. Diffuse axonal injury was measured using diffusion tensor imaging and focal injuries defined from T1 and FLAIR. Neuropsychological assessment was performed.ResultsAbnormal progressive brain atrophy was seen after TBI (~1.8%/year in white matter). This was accompanied by widespread reductions in fractional anisotropy, in keeping with the presence of diffuse axonal injury. There was a strong negative correlation between FA and brain atrophy, whereby areas of greater white matter damage showed greater atrophy over time.ConclusionsThe results show a strong relationship between the location of diffuse axonal injury and subsequent neurodegeneration. This suggests that TBI triggers progressive neurodegeneration through the long-lasting effects of diffuse axonal injury.

scholarly journals Widespread and dynamic changes in the white matter in moderate and severe TBI victims - how diffuse axonal injury relates to different cognitive domains after trauma

2020 ◽  
Author(s):  
Celi Santos Andrade ◽  
Daphine Centola Grassi ◽  
Ana Luiza Costa Zaninotto ◽  
Fabrício Stewan Feltrin ◽  
Fabíola Bezerra de Carvalho Macruz ◽  
...  
Keyword(s):  
White Matter ◽  
Axonal Injury ◽  
Diffuse Axonal Injury ◽  
Dynamic Changes ◽  
Cognitive Domains ◽  
Severe Tbi

Proton magnetic resonance spectroscopy for detection of axonal injury in the splenium of the corpus callosum of brain-injured patients

1998 ◽  
Vol 88 (5) ◽  
pp. 795-801 ◽  
Author(s):  
Kim M. Cecil ◽  
Everett C. Hills ◽  
M. Elizabeth Sandel ◽  
Douglas H. Smith ◽  
Tracy K. McIntosh ◽  
...  
Keyword(s):  
White Matter ◽  
Proton Magnetic Resonance ◽  
Axonal Injury ◽  
Diffuse Axonal Injury ◽  
Resonance Spectroscopy ◽  
Proton Mrs ◽  
Content Type ◽  
Brain Injured ◽  
Injured Patients ◽  
Fine Print

Object. This study was conducted to determine whether proton magnetic resonance spectroscopy (MRS) is a sensitive method for detecting diffuse axonal injury, which is a primary sequela of traumatic brain injury (TBI). Diffuse axonal injury is characterized by selective damage to white matter tracts that is caused in part by the severe inertial strain created by rotational acceleration and deceleration, which is often associated with motor vehicle accidents. This axonal injury is typically difficult to detect by using conventional imaging techniques because it is microscopic in nature. The splenium was selected because it is a site vulnerable to shearing forces that produce diffuse axonal injury. Methods. The authors used proton MRS to evaluate the splenium, the posterior commissure of the corpus callosum, in normal control volunteers and in patients with TBI. Proton MRS provided an index of neuronal and axonal viability by measuring levels of N-acetyl aspartate (NAA). Conclusions. A majority of mildly brain injured patients, as well as those more severely injured, showed diminished NAA/creatine (Cr) levels in the splenium compared with normal control volunteers. The patients displaying lowered NAA/Cr in the splenium were also likely to exhibit lowered NAA/Cr in lobar white matter. Also, the levels of NAA/Cr in the splenium of normal volunteers were higher compared with those found in lobar white matter. Decreases in NAA/Cr levels in the splenium may be a marker for diffuse injury. A proton MRS examination may be particularly useful in evaluating mildly injured patients with unexplained neurological and cognitive deficits. It is concluded that MRS is a sensitive tool in detecting axonal injury.

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