Journal of neurotrauma
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Journal of neurotrauma · Aug 2020
White matter changes caused by mild traumatic brain injury in mice evaluated using neurite orientation dispersion and density imaging.
Mild traumatic brain injury (mTBI) is common and can lead to persistent cognitive and behavioral symptoms. Although diffusion tensor imaging (DTI) has demonstrated some sensitivity to changes in white matter following mTBI, recent studies have suggested that more complex geometric models of diffusion, including the neurite orientation dispersion and density imaging (NODDI) model, may be more sensitive and specific. Here, we evaluate microstructural changes in white matter following mTBI using DTI and NODDI in a mouse model, and compare the time course of these changes to behavioral impairment and recovery. ⋯ A transient impairment in working memory was observed, which resolved by 6 weeks, whereas increased ODI, GFAP, and Iba1 persisted to 18 weeks post-injury. We conclude that the optic tracts are particularly vulnerable to damage from the closed-skull impact model used in this study, and that ODI may be a more sensitive metric to this damage than FA. Differences in ODI and in histological measures of astrogliosis, neuroinflammation, and axonal degeneration persist beyond behavioral impairment in this model.
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Journal of neurotrauma · Aug 2020
Sleep disruption exacerbates and prolongs the inflammatory response to traumatic brain injury.
Traumatic brain injury (TBI) alters stress responses, which may influence neuroinflammation and behavioral outcome. Sleep disruption (SD) is an understudied post-injury environmental stressor that directly engages stress-immune pathways. Thus, we predicted that maladaptive changes in the hypothalamic-pituitary-adrenal (HPA) axis after TBI compromise the neuroendocrine response to SD and exacerbate neuroinflammation. ⋯ Strikingly, TBI SD mice displayed an increased number of CD45+ cells near the site of injury, enhanced cortical glial fibrillary acidic protein (GFAP) immunolabeling, and persistent expression of Trem2 and Tlr4 7 DPI compared with TBI mice. These results support the hypothesis that post-injury SD alters stress-immune pathways and inflammatory outcomes after TBI. These data provide new insight to the dynamic interplay between TBI, stress, and inflammation.
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Journal of neurotrauma · Aug 2020
Magnetic resonance imaging biomarkers of brain connectivity in predicting outcome after mild traumatic brain injury: a systematic review.
There is growing interest in developing magnetic resonance imaging (MRI) biomarkers of brain connectivity from resting-state functional (rs-fMRI) and diffusion tensor imaging (DTI) to aid in the diagnosis and management of patients with mild traumatic brain injury (mTBI). To determine whether early MRI biomarkers of brain connectivity are useful in predicting outcome after mTBI, we conducted a systematic review using the following inclusion criteria: 1) patients aged >16 years with mTBI, 2) MRI performed during the first month post-injury, 3) outcome measure available, 4) control group, and 5) original article published in a peer-reviewed journal. Of the 1351 citations identified, 14 studies met inclusion criteria (5 rs-fMRI and 10 DTI; 680 patients with mTBI vs. 436 controls) including those where MRI was performed from <12 h to 1 month post-injury. ⋯ The most frequently studied brain connectivity MRI biomarkers were global functional connectivity, default-mode network, and fractional anisotropy (FA). Despite the scant evidence and considerable methodological heterogeneity observed among studies, we conclude that brain connectivity MRI biomarkers obtained within 1 month of injury may be potentially useful in predicting outcome in mTBI. Further longitudinal studies are needed to evaluate the effect of mTBI on MRI-based brain connectivity biomarkers and examine how incorporation of these tests can inform the clinical care of individual mTBI patients.
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Journal of neurotrauma · Aug 2020
Multicenter Study Comparative StudyComparison of care system and treatment approaches for patients with Traumatic Brain Injury in China versus Europe: a CENTER-TBI survey study.
Traumatic brain injury (TBI) poses a huge public health and societal problem worldwide. Uncertainty exists on how care system and treatment approaches for TBI worked in China may differ from those in Europe. Better knowledge on this is important to facilitate interpretation of findings reported by Chinese researchers and to inform opportunities for collaborative studies. ⋯ For treatment of refractory intracranial hypertension, a decompressive craniectomy was more frequently regarded as general policy in China compared with in Europe (89% vs. 45%). We observed both concordance and substantial variations with regard to the various aspects of TBI care between Chinese and European centers. These findings are fundamental to guide future research and offer opportunities for collaborative comparative effectiveness research to identify best practices.
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Journal of neurotrauma · Aug 2020
Multiple object tracking scores predict post-concussion status years after mild traumatic brain injury.
The diagnosis of concussion remains challenging, particularly in cases where several months have passed between a traumatic brain injury (TBI) and clinical assessment. Tracking multiple moving objects in three-dimensional (3D) space engages many of the same cognitive processes that are affected by concussion, a form of mild TBI (mTBI), suggesting that tests of 3D multiple object tracking (3D-MOT) may be sensitive to post-concussion syndrome (PCS) after a brain injury has occurred. ⋯ Persons with a history of concussion in the past 37 days were predicted to have pPCS if they were ≥35 years of age, or if they were <35 years of age but achieved scores below 1.2 on the 3D-MOT. These results demonstrate the potential of 3D-MOT for pPCS diagnosis and highlight the increased vulnerability to concussion symptoms that comes with age.