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
Review Meta AnalysisOlfactory dysfunction in pediatric traumatic brain injury: A systematic review.
The neuropsychological outcomes of pediatric traumatic brain injury (TBI) have received increasing study over the past 20 years and are currently well delineated in the research literature. One outcome that has received little attention is that of olfactory dysfunction after pediatric TBI. This is despite literature indicating that anosmia and olfactory dysfunction are common after adult TBI and are likely to be linked to severity of injury, neuropathology, and executive dysfunction. ⋯ The studies found were limited by methodological weaknesses, variability in measures, small sample size, and difficulty of comparison across cohorts studied. Despite this, they reported consistent findings of anosmia and olfactory dysfunction in their TBI cohorts and identified a dose-response relationship between severity of injury and olfactory dysfunction. The results of the studies are discussed in terms of relevant findings, limitations, and areas requiring further exploration.
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Journal of neurotrauma · Feb 2014
A follow-up study of neurometabolic alterations in female concussed athletes.
Athletes who sustain a concussion demonstrate a variety of symptoms and neuropsychological alterations that could be brought on by neurometabolic abnormalities. However, no study has yet investigated these aspects in female athletes using magnetic resonance spectroscopy. The present study investigated the neurometabolic and -psychological effects of a concussion in the acute (7-10 days postinjury) and chronic (6 months postinjury) phases after injury. ⋯ Concussed athletes showed neurometabolic impairment in prefrontal and motor cortices characterized by a pathological increase of glutamine/glutamate and creatine (Cr) only in the chronic phase. Also, a significant decrease in N-acetyl-aspartate/Cr ratio was observed in control athletes at the second time point. Concussed female athletes showed acute cognitive alterations and higher severity of symptoms that do not appear to be underlied by neurometabolic abnormalities, which are only present in the chronic postinjury phase.
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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
Amantadine Improves Cognitive Outcome and Increases Neuronal Survival after Fluid Percussion TBI in Rats.
This study evaluated the effects of clinically relevant concentrations of amantadine (AMT) on cognitive outcome and hippocampal cell survival in adult rats after lateral fluid percussion traumatic brain injury (TBI). AMT is an antagonist of the N-methyl-D-aspartate-type glutamate receptor, increases dopamine release, blocks dopamine reuptake, and has an inhibitory effect on microglial activation and neuroinflammation. Currently, AMT is clinically used as an antiparkinsonian drug. ⋯ Treatment with 135mg/kg/day of AMT improved acquisition of learning and terminal cognitive performance on MWM. The 135-mg/kg/day dosing of AMT increased the numbers of surviving CA2-CA3 pyramidal neurons at day 16 post-TBI. Overall, the data showed that clinically relevant dosing schedules of AMT affords neuroprotection and significantly improves cognitive outcome after experimental TBI, suggesting that it has the potential to be developed as a novel treatment of human TBI.