Journal of neurotrauma
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Journal of neurotrauma · Feb 2014
ReviewThe Presence and Role of Iron in Mild Traumatic Brain Injury: An Imaging Perspective.
Mild traumatic brain injury (mTBI), although often presenting without the gross structural abnormalities seen in more severe forms of brain trauma, can nonetheless result in lingering cognitive and behavioral problems along with subtle alterations in brain structure and function. Repeated injuries are associated with brain atrophy and dementia in the form of chronic traumatic encephalopathy (CTE). The mechanisms underlying these dysfunctions are poorly understood. ⋯ In addition, there is evidence that iron may contribute to pathology after mTBI through a number of mechanisms, including generation of reactive oxygen species (ROS), exacerbation of oxidative stress from other sources, and encouragement of tau phosphorylation and the formation of neurofibrillary tangles. Finally, recent animal studies suggest that iron may serve as a therapeutic target in mitigating the effects of mTBI. However, research on the presence and role of iron in mTBI and CTE is still relatively sparse, and further work is necessary to elucidate issues such as the sources of increased iron and the chain of secondary injury.
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Journal of neurotrauma · Feb 2014
Hypopituitarism in Pediatric Survivors of Inflicted Traumatic Brain Injury.
Endocrine dysfunction is common after accidental traumatic brain injury (TBI). Prevalence of endocrine dysfunction after inflicted traumatic brain injury (iTBI) is not known. The aim of this study was to examine endocrinopathy in children after moderate-to-severe iTBI. ⋯ Larger, multi-center, prospective studies would provide more data to determine the extent of endocrine dysfunction in iTBI. We recommend that any child with a history of iTBI be followed closely for growth velocity and pubertal changes. If growth velocity is slow, PRL level and a full endocrine evaluation should be performed.
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Journal of neurotrauma · Feb 2014
Blockage of the Upregulation of Voltage-Gated Sodium Channel Nav1.3 Improves Outcomes after Experimental Traumatic Brain Injury.
Excessive active voltage-gated sodium channels are responsible for the cellular abnormalities associated with secondary brain injury following traumatic brain injury (TBI). We previously presented evidence that significant upregulation of Nav1.3 expression occurs in the rat cortex at 2 h and 12 h post-TBI and is correlated with TBI severity. In our current study, we tested the hypothesis that blocking upregulation of Nav1.3 expression in vivo in the acute stage post-TBI attenuates the secondary brain injury associated with TBI. ⋯ The Morris water maze memory retention test showed that both the aCSF and ODN groups took longer to find a hidden platform, compared with the sham group (p<0.01). However, latency in the aCSF group was significantly higher than in the ODN group (p<0.05). Our in vivo Nav1.3 inhibition studies suggest that therapeutic strategies to block upregulation of Nav1.3 expression in the brain may improve outcomes following TBI.
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Journal of neurotrauma · Feb 2014
Early Platelet Dysfunction in a Rodent Model of Blunt Traumatic Brain Injury Reflects the Acute Traumatic Coagulopathy Found in Humans.
Acute coagulopathy is a serious complication of traumatic brain injury (TBI) and is of uncertain etiology because of the complex nature of TBI. However, recent work has shown a correlation between mortality and abnormal hemostasis resulting from early platelet dysfunction. ⋯ Studies utilizing a highly reproducible constrained blunt-force brain injury in rats demonstrate a strong correlation with important postinjury pathological changes that are observed in human TBI patients, namely, diminished platelet responses to agonists, especially adenosine diphosphate (ADP), and subarachnoid bleeding. Additionally, administration of a direct thrombin inhibitor, preinjury, recovers platelet functionality to ADP stimulation, indicating a direct role for excess thrombin production in TBI-induced early platelet dysfunction.
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Journal of neurotrauma · Feb 2014
Erythropoietin Improved Cognitive Function and Decreased Hippocampal Caspase Activity in Rat Pups after Traumatic Brain Injury.
Traumatic brain injury (TBI) is a leading cause of acquired neurologic disability in children. Erythropoietin (EPO), an anti-apoptotic cytokine, improved cognitive outcome in adult rats after TBI. To our knowledge, EPO has not been studied in a developmental TBI model. ⋯ EPO normalized recognition memory after CCI. EPO blunted the increased hippocampal caspase activity induced by CCI at PID1, but not at PID2. EPO increased neuron fraction in CA3 at PID2. Brain levels of exogenous EPO appeared low relative to endogenous. Timing of EPO administration was associated with temporal changes in hippocampal mRNA levels of EPO and pro-apoptotic factors. Conclusion/Speculation: EPO improved recognition memory, increased regional hippocampal neuron fraction, and decreased caspase activity in P17 rats after CCI. We speculate that EPO improved cognitive outcome in rat pups after CCI as a result of improved neuronal survival via inhibition of caspase-dependent apoptosis early after injury.