Journal of neurotrauma
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Journal of neurotrauma · Nov 2012
Blast exposure induces post-traumatic stress disorder-related traits in a rat model of mild traumatic brain injury.
Blast related traumatic brain injury (TBI) has been a major cause of injury in the wars in Iraq and Afghanistan. A striking feature of the mild TBI (mTBI) cases has been the prominent association with post-traumatic stress disorder (PTSD). However, because of the overlapping symptoms, distinction between the two disorders has been difficult. ⋯ We also found elevation in the amygdala of the protein stathmin 1, which is known to influence the generation of fear responses. Because the blast overpressure injuries occurred while animals were under general anesthesia, our results suggest that a blast-related mTBI exposure can, in the absence of any psychological stressor, induce PTSD-related traits that are chronic and persistent. These studies have implications for understanding the relationship of PTSD to mTBI in the population of veterans returning from the wars in Iraq and Afghanistan.
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Journal of neurotrauma · Nov 2012
Calpastatin overexpression protects axonal transport in an in vivo model of traumatic axonal injury.
Traumatic brain injury (TBI) causes substantial morbidity and mortality worldwide. A key component of both mild and severe TBI is diffuse axonal injury. Except in cases of extreme mechanical strain, when axons are torn at the moment of trauma, axonal stretch injury is characterized by early cytoskeletal proteolysis, transport disruption, and secondary axotomy. ⋯ Both hCAST and ZsGreen were detected in axons throughout the optic nerve to the chiasm. Calpastatin overexpression partially preserved axonal transport after stretch injury (58.3±15.6% reduction in Fluoro-Gold labeling relative to uninjured contralateral controls in ZsGreen-expressing RGCs, versus 33.8±23.9% in hCAST-expressing RGCs; p=0.038). These results provide direct evidence that axonal calpains play a causal role in transport disruption after in vivo stretch injury.
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Journal of neurotrauma · Nov 2012
ReviewA systematic review of diffusion tensor imaging findings in sports-related concussion.
Sports-related concussion (SRC) is typically associated with functional, as opposed to structural, injury. The results of traditional structural neuroimaging techniques used to assess SRC tend to be normal in many athletes, and are only clinically helpful in ruling out a more serious injury. Diffusion tensor imaging (DTI) has increasingly been touted as a method offering greater clinical potential in mild traumatic brain injury (mTBI). ⋯ Seven of eight studies reported some type of DTI abnormality, although the neuroanatomical sites involved varied. Although considerable methodological variations exist across studies, the current review suggests that DTI may possess adequate diagnostic sensitivity to detect SRC in affected athletes. Further longitudinal studies are required to demonstrate its discriminate validity and prognostic capacity within this field.
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Journal of neurotrauma · Nov 2012
Functional recovery ten years after pediatric traumatic brain injury: outcomes and predictors.
Functional impairments (adaptive, behavioral, educational) are common after preschool traumatic brain injury (TBI). In comparison with cognitive outcome, functional outcomes have received limited attention, with little evidence to determine whether these difficulties persist in the long term. The aim of this study was to examine functional outcomes at 10 years post-injury and identify predictors of outcome. ⋯ Post-injury, arithmetic skills were the most compromised in the longer term. Pre-injury status, interventions accessed, and acute intellectual function were significant predictors of outcome. These results highlight the importance of monitoring functional skills in the long term, especially for those children presenting with risk factors.
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Journal of neurotrauma · Nov 2012
Gracile neurons contribute to the maintenance of neuropathic pain in peripheral and central neuropathic models.
In the present study, we compared the roles of gracile neurons in mechanically-induced neuropathic pain caused by spinal injury and L5 spinal nerve ligation in rats. Behavioral and electrophysiological methods were used to measure mechanical allodynia in the hindpaws, and excitability of the gracile neurons in the medulla, respectively. In the spinal hemisection and spinal contusion models, mechanical allodynia developed in both hindpaws and lasted over a month. ⋯ In addition, WDR neuronal activity at the ipsilateral gracile neurons showed a significant increase with non-noxious mechanical stimuli, whereas the LT neurons did not show significant changes (*p<0.05). Similarly to the hemisection model, a lesion of the gracile nucleus attenuated the mechanical allodynia in spinal nerve ligation models. The present data suggest that gracile neurons contribute to the maintenance of non-noxious mechanically-induced neuropathic pain in both hemisection- and ligation-induced neuropathic pain in rats.