Neuroimaging of Traumatic Brain Injury

Douglas, David; Ro, Tae H.; Toffoli, Thomas; Krawchuk, Bennet; Muldermans, Jonathan; Gullo, James; Dulberger, Adam; Anderson, Ariana; Douglas, Pamela K.; Wintermark, Max

doi:10.3390/medsci7010002

Cited by 25 publications

(26 citation statements)

References 129 publications

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“…Due to its wide availability and sensitivity to microstructural injury, diffusion tensor imaging (DTI) is at the forefront of quantitative magnetic resonance-based methods applied thus far to TBI. 9 The main DTI metrics are the fractional anisotropy (FA), a scalar value that describes the anisotropy of water diffusion, and the apparent diffusion coefficient (ADC), a measure of the average diffusion. Unfortunately, there are often contradictory results in regard to the presence, direction, anatomical location and causative aetiology of the reported diffusional changes.…”

Section: Introductionmentioning

confidence: 99%

Global decrease in brain sodium concentration after mild traumatic brain injury

Gerhalter

Chen

Dehkharghani

et al. 2021

Brain Communications

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The pathological cascade of tissue damage in mild traumatic brain injury is set forth by a perturbation in ionic homeostasis. However, whether this class of injury can be detected in vivo and serve as a surrogate marker of clinical outcome is unknown. We employ sodium MRI to test the hypotheses that regional and global total sodium concentrations: (i) are higher in patients than in controls; and (ii) correlate with clinical presentation and neuropsychological function. Given the novelty of sodium imaging in traumatic brain injury, effect sizes from (i), and correlation types and strength from (ii), were compared to those obtained using standard diffusion imaging metrics. 27 patients (20 female, age 35.9 ± 12.2 years) within two months after injury and 19 controls were scanned with proton and sodium MRI at 3 Tesla. Total sodium concentration, fractional anisotropy and apparent diffusion coefficient were obtained with voxel averaging across 12 grey and white matter regions. Linear regression was used to obtain global grey and white matter total sodium concentrations. Patient outcome was assessed with global functioning, symptom profiles, and neuropsychological function assessments. In the regional analysis, there were no statistically significant differences between patients and controls in apparent diffusion coefficient, while differences in sodium concentration and fractional anisotropy were found only in single regions. However, for each of the 12 regions, sodium concentration effect sizes were uni-directional, due to lower mean sodium concentration in patients compared to controls. Consequently, linear regression analysis found statistically significant lower global grey and white matter sodium concentrations in patients compared to controls. The strongest correlation with outcome was between global grey matter sodium concentration and the composite z-score from the neuropsychological testing. In conclusion, both sodium concentration and diffusion showed poor utility in differentiating patients from controls, and weak correlations with clinical presentation, when using a region-based approach. In contrast, sodium linear regression, capitalizing on partial volume correction and high sensitivity to global changes, revealed high effect sizes and associations with patient outcome. This suggests that well-recognized sodium imbalances in traumatic brain injury are: (i) detectable non-invasively, (ii) non-focal, (iii) occur even when the antecedent injury is clinically mild. Finally, in contrast to our principle hypothesis, patients’ sodium concentrations were lower than controls, indicating that the biological effect of traumatic brain injury on the sodium homeostasis may differ from that in other neurological disorders.

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Section: Introductionmentioning

confidence: 99%

Global decrease in brain sodium concentration after mild traumatic brain injury

Gerhalter

Chen

Dehkharghani

et al. 2021

Brain Communications

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“…The injuries are seldom visible on computed tomography (CT) and conventional MRI scans, besides the fact that not many approaches are available to assess the WM damage [27]. Previous studies have suggested that the DAI is only visible by using advanced neuroimaging techniques that can distinguish microstructural tissue damages [28]; [29]. Using Diffusion tensor imaging (DTI), WM connectivity, and integrity changes can be identified by several measures of diffusion anisotropy along fiber tracts [30].…”

Section: Introductionmentioning

confidence: 99%

Graph-theoretical Analysis of EEG Functional Connectivity during Balance Perturbation in Traumatic Brain Injury: A Pilot Study

Handiru

Alivar

Hoxha

et al. 2020

Preprint

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Traumatic Brain Injury (TBI) often results in balance impairment, increasing the risk for falls and further injuries. In this study, we investigated the postural instability in a group of 12 TBI patients vs 9 healthy controls (HC) by studying their brain’s response to an external perturbation of the computerized dynamic posturography platform. A 64-channel EEG was used to noninvasively record the brain’s anticipatory response while the participant was performing the dynamic posturography task. We used the global graph-theoretic network measures (global efficiency and modularity) derived from source-space EEG connectivity in different frequency bands as quantitative measures of the functional integration and segregation of the brain network during the task. The center of pressure (COP) displacement and the Berg Balance Scale (BBS) were used as balance outcomes. Furthermore, we used the Diffusion Tensor Imaging (DTI) data from all the participants to explore the association between the measures of the structural integrity of the white matter (Fractional Anisotropy, Mean Diffusivity, and Mode of Anisotropy) and the balance outcomes.Our findings revealed significant changes in functional segregation between the TBI group and controls during the task and also group-level differences in DTI measures. Also, we observed significant differences between theta-band modularity and global efficiency during rest vs. task within both the groups (TBI and HC). In terms of the neural correlates, we observed a distinct role played by different frequency bands; increase in theta-band modularity during the task was shown to be highly correlated with the poorer COP displacement and BBS in the TBI group; alpha-band and beta-band graph-theoretic measures were correlated with the measures of structural integrity. In terms of the regions of interest pertaining to the postural control, we noticed a significant cortical activity during the task in the paracentral lobule, post-central gyrus, cingulate gyrus, superior parietal gyrus, and other regions often reported to be involved in postural stability.Our study, although limited by small sample size, provides insights into the neural correlates of the balance deficits due to brain injury. Our future studies will focus on the larger sample size and also the effect of stabilometry platform training on the functional brain network modulation in TBI.

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“…Because of its rapid acquisition time and sensitivity to intracranial hemorrhage, computed tomography (CT) is the imaging modality of choice in traumatic brain injury (TBI). 1 , 2 There are, however, instances in which the severity of a patient's neurological condition does not coincide with CT findings, a phenomenon that is indicative of traumatic axonal injuries (TAI). Th17e TAI, also referred to as diffuse axonal injuries (DAI), occur as a consequence of angular acceleration-deceleration forces that are exerted on the brain at the time of injury, leading to a shearing of axons.…”

Section: Introductionmentioning

confidence: 99%

Extended Analysis of Axonal Injuries Detected Using Magnetic Resonance Imaging in Critically Ill Traumatic Brain Injury Patients

Tjerkaski

Nyström

Raj

et al. 2022

Journal of Neurotrauma

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Studies show conflicting results regarding the prognostic significance of traumatic axonal injuries (TAI) in patients with traumatic brain injury (TBI). Therefore, we documented the presence of TAI in several brain regions, using different magnetic resonance imaging (MRI) sequences, and assessed their association to patient outcomes using machine learning. Further, we created a novel MRI-based TAI grading system with the goal of improving outcome prediction in TBI. We subsequently evaluated the performance of several TAI grading systems. We used a genetic algorithm to identify TAI that distinguish favorable from unfavorable outcomes. We assessed the discriminatory performance (area under the curve [AUC]) and goodness-of-fit (Nagelkerke pseudo-R 2 ) of the novel Stockholm MRI grading system and the TAI grading systems of Adams and associates, Firsching and coworkers. and Abu Hamdeh and colleagues, using both univariate and multi-variate logistic regression. The dichotomized Glasgow Outcome Scale was considered the primary outcome. We examined the MRI scans of 351 critically ill patients with TBI. The TAI in several brain regions, such as the midbrain tegmentum, were strongly associated with unfavorable outcomes. The Stockholm MRI grading system exhibited the highest AUC (0.72 vs. 0.68–0.69) and Nagelkerke pseudo-R 2 (0.21 vs. 0.14–0.15) values of all TAI grading systems. These differences in model performance, however, were not statistically significant (DeLong test, p > 0.05). Further, all included TAI grading systems improved outcome prediction relative to established outcome predictors of TBI, such as the Glasgow Coma Scale (likelihood-ratio test, p < 0.001). Our findings suggest that the detection of TAI using MRI is a valuable addition to prognostication in TBI.

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Neuroimaging of Traumatic Brain Injury

Cited by 25 publications

References 129 publications

Global decrease in brain sodium concentration after mild traumatic brain injury

Global decrease in brain sodium concentration after mild traumatic brain injury

Graph-theoretical Analysis of EEG Functional Connectivity during Balance Perturbation in Traumatic Brain Injury: A Pilot Study

Extended Analysis of Axonal Injuries Detected Using Magnetic Resonance Imaging in Critically Ill Traumatic Brain Injury Patients

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