ROLE OF MRI IN THE EVALUATION OF DIFFUSE AXONAL INJURY

2021 ◽  
pp. 60-61
Author(s):  
Sumit Baviskar ◽  
Sneha Mote ◽  
Vishakha Gajre ◽  
Azhar Patwe
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
White Matter ◽  
Axonal Injury ◽  
Diffuse Axonal Injury ◽  
Severe Form ◽  
Cerebral White Matter ◽  
Gradient Echo ◽  
The Brain

INTRODUCTION: Diffuse axonal injury (DAI) is a relatively less common but severe form of traumatic brain injury. It occurs due to shearing forces and is identied as one of the most important causes of morbidity and mortality in patients with traumatic brain injury. MRI is found to be diagnostic when CTndings are normal and there are persistent unexplained neurologic ndings or at subacute and chronic periods. AIM: To evaluate the role of MRI in the diagnosis of diffuse axonal injury. MATERIALAND METHODS: 9 Subjects were identied retrospectively with the diagnosis of DAI on MRI in last 2 years. The 1.5TMRI scans of the patients with DAI included: T1 and T2- weighted imaging, FLAIR imaging and T2*-weighted gradient echo (GRE) imaging. Lesions were identied and compared on all sequences. RESULTS: The lesions were in cerebral white matter location in the cases of mild DAI, whereas in the severe DAI located in basal ganglia, corpus callosum, dorsal part of the brain stem as well as the cerebral white matter. For Haemorrhagic lesions, GRE is the best tool to detect haemorrhagic DAIs. For Non-haemorrhagic lesion, FLAIR and DWI are the best current tool to detect small and non-haemorrhagic parenchymal lesions, displayed as hyperintense lesions.

A Finite Element Model for Estimating Axonal Damage in Traumatic Brain Injury

2012 ◽  
Author(s):  
Rika M. Wright ◽  
K. T. Ramesh
Keyword(s):  
Traumatic Brain Injury ◽  
Finite Element ◽  
Brain Injury ◽  
White Matter ◽  
Finite Element Model ◽  
Axonal Injury ◽  
Diffuse Axonal Injury ◽  
Element Model ◽  
Cellular Level ◽  
The Brain

There has been an ongoing effort to reduce the occurrence of sports-related traumatic brain injury. These injuries are caused by an impact to the head and often lead to the damage of neural axons in the brain. This type of damage is classified as diffuse axonal injury (DAI) or traumatic axonal injury (TAI) [1]. One of the difficulties in studying the progression of axonal injury is that the structural signature of DAI cannot be readily visualized with conventional medical imaging modalities since the damage occurs at the cellular level [2]. This also makes the injury difficult to diagnose. Many researchers have turned to finite element (FE) models to study the development of diffuse axonal injury. FE models provide a means for observing the mechanical process of injury development from the loads to the head at the macroscale to the damage that results at the cellular level. However, for a finite element model to be a viable tool for studying DAI, the model must be able to accurately represent the behavior of the brain tissue, and it must be able to accurately predict injury. In this work, we address both of these issues in an effort to improve the material models and injury criteria used in current FE models of TBI. We represent the white matter with an anisotropic, hyper-viscoelastic constitutive model, incorporate the microstructure of the white matter through the use of diffusion tensor imaging (DTI), and estimate injury using an axonal strain injury (ASI) criterion (Figure 1). We also develop a novel method to quantify the degree of axonal damage in the fiber tracts of the brain.

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 Modeling the Encephalopathy of Prematurity in Animals: The Important Role of Translational Research

2012 ◽  
Vol 2012 ◽  
pp. 1-17 ◽  
Author(s):  
Hannah C. Kinney ◽  
Joseph J. Volpe
Keyword(s):  
Brain Injury ◽  
White Matter ◽  
Animal Models ◽  
Translational Research ◽  
Developmental Trajectories ◽  
Axonal Injury ◽  
White Matter Lesions ◽  
Human Condition ◽  
Cerebral White Matter

Translational research in preterm brain injury depends upon the delineation of the human neuropathology in order that animal models faithfully reiterate it, thereby ensuring direct relevance to the human condition. The major substrate of human preterm brain injury is the encephalopathy of prematurity that is characterized by gray and white matter lesions reflecting combined acquired insults, altered developmental trajectories, and reparative phenomena. Here we highlight the key features of human preterm brain development and the encephalopathy of prematurity that are critical for modeling in animals. The complete mimicry of the complex human neuropathology is difficult in animal models. Many models focus upon mechanisms related to a specific feature, for example, loss of premyelinating oligodendrocytes in the cerebral white matter. Nevertheless, animal models that simultaneously address oligodendrocyte, neuronal, and axonal injury carry the potential to decipher shared mechanisms and synergistic treatments to ameliorate the global consequences of the encephalopathy of prematurity.

scholarly journals The importance of multidisciplinary team in the treatment of severe traumatic brain injury

2020 ◽  
Vol 11 (Vol.11, no.3) ◽  
pp. 368-371
Author(s):  
Corina ROMAN-FILIP ◽  
Maria-Gabriela CATANĂ
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Axonal Injury ◽  
Diffuse Axonal Injury ◽  
Young Patients ◽  
Neurological Status ◽  
The Past ◽  
Precise Representation ◽  
The Times ◽  
The Brain

Noticeable advances have occurred in the field of traumatic brain injury in the past ten years. Brain imagery provides a more precise representation of what occurs in the brain, diffuse axonal injury being an important cause of morbidity and mortality in patients with traumatic brain injury. We present 2 cases that were admitted and discharged from our department. Actually we want to emphasize differences and similarities between the two cases and to highlight different sequelae that traumatic brain injury can do in young patients. Both patients were admitted in a critical state – GCS 4 points and were discharged with an improved neurological status after approximately 30 days. We decided to present these cases to issue a warning about the rehabilitation for these patients which most of the times have a prolonged hospitalization. We wanted to highlight that the rehabilitation does not consist only in the motor part, but in the psychiatric and behaviour part too.

scholarly journals Pathomorphology and expert assessment of a diffuse axonal injury of the brain

2013 ◽  
Vol 17 (3 (67) p.1) ◽  
pp. 43-44
Author(s):  
O. I. Gerasimenko ◽  
Ye. G. Polivoda
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Axonal Injury ◽  
Diffuse Axonal Injury ◽  
Morphological Features ◽  
Expert Assessment ◽  
The Brain

The prevalence of diffuse axonal brain injury (DAI) among 936 people with a traumatic brain injury was investigated. Specific morphological features, permitting to diagnose DAI, and to determine the prescription of injuries have been determined by means of histological methods of research.

Simulating Diffuse Axonal Injury During Traumatic Brain Injury Events

2011 ◽  
Author(s):  
Jean-Pierre Dolle ◽  
Rene Schloss ◽  
Martin L. Yarmush
Keyword(s):  
United States ◽  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Brain Injuries ◽  
Axonal Injury ◽  
Diffuse Axonal Injury ◽  
The United States ◽  
Traumatic Brain Injuries ◽  
Inertial Forces ◽  
The Brain

Traumatic Brain Injuries (TBI) affect up to 1.5 million people annually within the United States with as many as 250,000 being hospitalized and 50,000 dying [1]. TBI events occur when the brain experiences a sudden trauma such as a rapid acc/deceleration. These events produce high inertial forces that result in a shearing or elongation of axons (commonly known as Diffuse Axonal Injury [2].

scholarly journals Diffuse axonal injury predicts neurodegeneration after moderate–severe traumatic brain injury

Brain ◽  
2020 ◽  
Author(s):  
Neil S N Graham ◽  
Amy Jolly ◽  
Karl Zimmerman ◽  
Niall J Bourke ◽  
Gregory Scott ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
White Matter ◽  
Fractional Anisotropy ◽  
Severe Traumatic Brain Injury ◽  
Brain Atrophy ◽  
Diffusion Mri ◽  
Axonal Injury ◽  
Diffuse Axonal Injury ◽  
Post Traumatic

Abstract Traumatic brain injury is associated with elevated rates of neurodegenerative diseases such as Alzheimer’s disease and chronic traumatic encephalopathy. In experimental models, diffuse axonal injury triggers post-traumatic neurodegeneration, with axonal damage leading to Wallerian degeneration and toxic proteinopathies of amyloid and hyperphosphorylated tau. However, in humans the link between diffuse axonal injury and subsequent neurodegeneration has yet to be established. Here we test the hypothesis that the severity and location of diffuse axonal injury predicts the degree of progressive post-traumatic neurodegeneration. We investigated longitudinal changes in 55 patients in the chronic phase after moderate–severe traumatic brain injury and 19 healthy control subjects. Fractional anisotropy was calculated from diffusion tensor imaging as a measure of diffuse axonal injury. Jacobian determinant atrophy rates were calculated from serial volumetric T1 scans as a measure of measure post-traumatic neurodegeneration. We explored a range of potential predictors of longitudinal post-traumatic neurodegeneration and compared the variance in brain atrophy that they explained. Patients showed widespread evidence of diffuse axonal injury, with reductions of fractional anisotropy at baseline and follow-up in large parts of the white matter. No significant changes in fractional anisotropy over time were observed. In contrast, abnormally high rates of brain atrophy were seen in both the grey and white matter. The location and extent of diffuse axonal injury predicted the degree of brain atrophy: fractional anisotropy predicted progressive atrophy in both whole-brain and voxelwise analyses. The strongest relationships were seen in central white matter tracts, including the body of the corpus callosum, which are most commonly affected by diffuse axonal injury. Diffuse axonal injury predicted substantially more variability in white matter atrophy than other putative clinical or imaging measures, including baseline brain volume, age, clinical measures of injury severity and microbleeds (>50% for fractional anisotropy versus <5% for other measures). Grey matter atrophy was not predicted by diffuse axonal injury at baseline. In summary, diffusion MRI measures of diffuse axonal injury are a strong predictor of post-traumatic neurodegeneration. This supports a causal link between axonal injury and the progressive neurodegeneration that is commonly seen after moderate/severe traumatic brain injury but has been of uncertain aetiology. The assessment of diffuse axonal injury with diffusion MRI is likely to improve prognostic accuracy and help identify those at greatest neurodegenerative risk for inclusion in clinical treatment trials.

Dynamic changes in white matter following traumatic brain injury and how diffuse axonal injury relates to cognitive domain

Brain Injury ◽  
2021 ◽  
pp. 1-10
Author(s):  
Daphine Centola Grassi ◽  
Ana Luiza Zaninotto ◽  
Fabrício Stewan Feltrin ◽  
Fabíola Bezerra Carvalho Macruz ◽  
Maria Concepción García Otaduy ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
White Matter ◽  
Axonal Injury ◽  
Diffuse Axonal Injury ◽  
Cognitive Domain ◽  
Dynamic Changes

scholarly journals Acute hemiplegia secondary to diffuse axonal injury after traumatic brain injury

2018 ◽  
Vol 20 (4) ◽  
pp. 436-438
Author(s):  
Leonardo Abdala Giacomini ◽  
Miguel San Martin Sepulveda ◽  
Rodrigo Alves de C. Cavalcante ◽  
Helder Tedeschi
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
White Matter ◽  
Vegetative State ◽  
Axonal Injury ◽  
Persistent Vegetative State ◽  
Diffuse Axonal Injury ◽  
Internal Capsule ◽  
Brain Structures ◽  
Motor Deficit

The diffuse axonal injury (DAI) is one of the main forms of traumatic brain injury, characterized by involvement of the axonal fibres of the white matter of the brain.The mechanism of such injury is the sum of forces of acceleration, deceleration and rotation, mainly in brain structures close to the middle line, including the dorsolateral superior region of the pons and midbrain, splenium of the corpus callosum, parasagittal white matter, and occasionally the internal capsule. Because of the importance of the structures commonly involved and its high incidence, close to 50 % of cases of severe brain trauma, the DAI is a major cause of cognitive impairment as well as the persistent vegetative state related to trauma. However, the occurrence of motor deficit outside of this area is uncommon in literature, and it is obviously dependant on the anatomical region involved6. The objective of this paper is to present a case of hemiplegia secondary to DAI.

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