Journal of neurotrauma
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Journal of neurotrauma · Aug 2017
Randomized Controlled TrialNeck collar with mild jugular vein compression ameliorates brain activation changes during a working memory task after a season of high school football.
Emerging evidence indicates that repetitive head impacts, even at a sub-concussive level, may result in exacerbated or prolonged neurological deficits in athletes. This study aimed to: 1) quantify the effect of repetitive head impacts on the alteration of neuronal activity based on functional magnetic resonance imaging (fMRI) of working memory after a high school football season; and 2) determine whether a neck collar that applies mild jugular vein compression designed to reduce brain energy absorption in head impact through "slosh" mitigation can ameliorate the altered fMRI activation during a working memory task. Participants were recruited from local high school football teams with 27 and 25 athletes assigned to the non-collar and collar group, respectively. ⋯ Areas displaying less activation change in the collar group (corrected p < 0.05) included the precuneus, inferior parietal cortex, and dorsal lateral prefrontal cortex. Additionally, BOLD response in the non-collar group increased significantly in direct association with the total number of impacts and total g-force (p < 0.05). Our data provide initial neuroimaging evidence for the effect of repetitive head impacts on the working memory related brain activity, as well as a potential protective effect that resulted from the use of the purported brain slosh reducing neck collar in contact sports.
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Journal of neurotrauma · Aug 2017
Observational StudyImpaired Cognitive Performance in Youth Athletes Exposed to Repetitive Head Impacts.
Worldwide, more than 22 million children and adolescents are exposed to repetitive head impacts (RHI) in soccer. Evidence indicates cumulative effects on brain structure, but it is not known whether exposure to RHI affects cognitive improvement in adolescents. The aim of the study was to determine whether exposure to RHI while heading the ball in soccer affects improvement in cognitive performance in adolescents over time. ⋯ Further, the more long headers performed, the slower the improvement in RT over the season. Youth athletes experience an immediate cognitive improvement after training most likely because of physical exercise. Results of this study also suggest an association between exposure to specific RHI (long headers) and lack of improvement in cognitive performance in youth athletes over time.
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Journal of neurotrauma · Aug 2017
ReviewDNA methylation: Basic biology and application to traumatic brain injury.
This article reviews the literature pertinent to epigenetic changes, and in particular, DNA methylation following traumatic brain injury (TBI). TBI is a heterogeneous disease that is a major cause of death and long-term disability. The links between TBI and epigenetics, the process by which environmental factors alter gene expression without changing the underlying DNA sequence, is an expanding area of research that may have profound consequences for understanding the disease, and for clinical care. ⋯ Here, we briefly describe the interaction of DNA methylation with the two other key epigenetic changes, and highlight key work being performed to understand the functional relevance of those mechanisms. The field of epigenetics is rapidly advancing as a result of the advent of less invasive and more versatile methods for measuring epigenetic proteins and their functional impact on cells; however, the evidence specific to TBI is limited. This review identifies several important outstanding questions that remain from the work already conducted, and highlights directions for the future.
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Journal of neurotrauma · Aug 2017
Cerebral perfusion pressure insults and associations with outcome in adult traumatic brain injury.
The definition of cerebral perfusion pressure (CPP) secondary insults in severe traumatic brain injury remains unclear. The purpose of the present study is to visualize the association of intensity and duration of episodes below or above CPP thresholds and outcome. The analysis was based on prospectively collected minute-by-minute intracranial pressure (ICP) and blood pressure data and outcome from 259 adult patients. ⋯ In the present study, the CPP pressure-time burden associated with poor outcome was visualized. A safe zone between 60 and 70 mm Hg could be identified for adults ≤65 years, provided AR was active and ICP was ≤25 mm Hg. Deficient AR reduces the tolerability for low CPP.
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Journal of neurotrauma · Aug 2017
Development of a Prediction Model for Post-Concussive Symptoms following Mild Traumatic Brain Injury: A TRACK-TBI Pilot Study.
Post-concussive symptoms occur frequently after mild traumatic brain injury (mTBI) and may be categorized as cognitive, somatic, or emotional. We aimed to: 1) assess whether patient demographics and clinical variables predict development of each of these three symptom categories, and 2) develop a prediction model for 6-month post-concussive symptoms. Patients with mTBI (Glasgow Coma Scale score 13-15) from the prospective multi-center Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) Pilot study (2010-2012) who completed the Rivermead Post Concussion Symptoms Questionnaire (RPQ) at 6 months post-injury were included. ⋯ The total set of predictors explained 21% of the variance, which decreased to 14% after bootstrap validation. Demographic and clinical variables at baseline are predictive of 6-month post-concussive symptoms following mTBI; however, these variables explain less than one-fifth of the total variance in outcome. Model refinement with larger datasets, more granular variables, and objective biomarkers are needed before implementation in clinical practice.