Journal of neurotrauma
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Journal of neurotrauma · Jul 2016
Simulated Aeromedical Evacuation Exacerbates Experimental Brain Injury.
Aeromedical evacuation, an important component in the care of many patients with traumatic brain injury (TBI), particularly in war zones, exposes them to prolonged periods of hypobaria. The effects of such exposure on pathophysiological changes and outcome after TBI are largely unexplored. The objective of this study was to investigate whether prolonged hypobaria in rats subjected to TBI alters behavioral and histological outcomes. ⋯ Hyperoxia during hypobaric exposure or two exposures to prolonged hypobaric conditions further exacerbated spatial memory deficits. These findings indicate that exposure to prolonged hypobaria up to 7 days after TBI, even while maintaining physiological oxygen concentration, worsens long-term cognitive function and neuroinflammation. Multiple exposures or use of 100% oxygen further exacerbates these pathophysiological effects.
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Journal of neurotrauma · Jul 2016
Review Meta AnalysisCoagulopathy in Traumatic Brain Injury and its Correlation with Progressive Hemorrhagic Injury: A Systematic Review and Meta-analysis.
The association between coagulopathy and either isolated traumatic brain injury (TBI) or progressive hemorrhagic injury (PHI) remains controversial. The aims of this study were to evaluate whether isolated TBI induces pronounced coagulopathy, in comparison with non-TBI or TBI in conjunction with other injuries (TBI + other injuries), and to examine whether there is any evidence of a relationship between coagulopathy and PHI in patients who have experienced TBI. The MEDLINE(®) and Embase databases, and the Cochrane Central Register of Controlled Trials (Central), were trawled for relevant studies. ⋯ The current clinical evidence does not indicate that the prevalence of coagulopathy in TBI is significantly higher than in injuries of similar severity to other areas of the body, or in multiple injuries with TBI. With respect to the association between coagulopathy and PHI, the occurrence of coagulopathy, INR, and PLT was significantly associated with PHI, but APTT and PT were not found to be associated with PHI. In the future, high quality research will be required to further characterize the effects of coagulopathy on TBI and subsequent PHI.
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Journal of neurotrauma · Jul 2016
Smaller Dentate Gyrus and CA 2 & 3 volumes are associated with kynurenine metabolites in collegiate football athletes.
An imbalance in kynurenine pathway metabolism is hypothesized to be associated with dysregulated glutamatergic neurotransmission, which has been proposed as a mechanism underlying the hippocampal volume loss observed in a variety of neurological disorders. Pre-clinical models suggest that the CA2-3 and dentate gyrus hippocampal subfields are particularly susceptible to excitotoxicity after experimental traumatic brain injury. We tested the hypothesis that smaller hippocampal volumes in collegiate football athletes with (n = 25) and without (n = 24) a concussion history would be most evident in the dentate gyrus and CA2-3 subfields relative to nonfootball healthy controls (n = 27). ⋯ Football athletes with and without a concussion history had a trend toward lower (p < 0.10) and significantly lower (p < 0.05) kynurenine levels compared with healthy controls, while athletes with a concussion history had greater levels of quinolinic acid compared with athletes without a concussion history (p < 0.05). Finally, plasma levels of 3-hydroxykynurenine inversely correlated with bilateral hippocampal volumes in football athletes with a concussion history (p < 0.01), and left hippocampal volume was correlated with the ratio of kynurenic acid to quinolinic acid in football athletes without a concussion history (p < 0.05). Our results raise the possibility that abnormalities of the kynurenine metabolic pathway constitute a mechanism for hippocampal volume differences in the context of sports-related brain injury.
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Journal of neurotrauma · Jul 2016
Post-inpatient Brain Injury Rehabilitation Outcomes: Report from the National OutcomeInfo Database.
This study examined outcomes for intensive residential and outpatient/community-based post-inpatient brain injury rehabilitation (PBIR) programs compared with supported living programs. The goal of supported living programs was stable functioning (no change). Data were obtained for a large cohort of adults with acquired brain injury (ABI) from the OutcomeInfo national database, a web-based database system developed through National Institutes of Health (NIH) Small Business Technology Transfer (STTR) funding for monitoring progress and outcomes in PBIR programs primarily with the Mayo-Portland Adaptability Inventory (MPAI-4). ⋯ Age at injury and time in program had small effects on outcome; the effect of chronicity was small to moderate. Examination of more chronic cases (>1 year post-injury) showed significant, but smaller (approximately 0.5 SD) change on the MPAI-4 relative to supported living programs (F = 17.562, p < 0.001). Results indicate that intensive residential and outpatient/community-based PIBR programs result in substantial positive functional changes moderated by chronicity.
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Journal of neurotrauma · Jul 2016
A Multidimensional Rasch Analysis of the Functional Independence Measure based on the NIDILRR Traumatic Brain Injury Model Systems National Database.
A number of studies have evaluated the psychometric properties of the Functional Independence Measure (FIM™) using Rasch analysis, although none has done so using the National Institute on Disability, Independent Living, and Rehabilitation Research Traumatic Brain Injury Model Systems National Database, a longitudinal database that captures demographic and outcome information on persons with moderate to severe traumatic brain injury across the United States. In the current study, we examine the psychometric properties of the FIM as represented by persons within this database and demonstrate that the FIM comprises three subscales representing cognitive, self-care, and mobility domains. These subscales were analyzed simultaneously using a multivariate Rasch model in combination with a time dependent concurrent calibration scheme with the goal of creating a raw score-to-logit transformation that can be used to improve the accuracy of parametric statistical analyses. ⋯ The strong correlations (r = 0.82-0.96) among the three subscales suggest they should be modeled together. Coefficient alpha of 0.98 indicates high internal consistency. Keyform maps are provided to enhance clinical interpretation and application of study results.