Journal of neurotrauma
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Journal of neurotrauma · Jun 2018
Divergent Classification Methods of Post-Concussion Syndrome after Mild Traumatic Brain Injury: Prevalence Rates, Risk Factors, and Functional Outcome.
Mild traumatic brain injury (mTBI) is a common diagnosis and approximately one third of mTBI patients experience a variety of cognitive, emotional, psychosocial, and behavioral post-concussion symptoms. When a cluster of these symptoms persists for more than 3 months they are often classified as post-concussion syndrome (PCS). The objective of this study was to determine prevalence rates, risk factors, and functional outcome associated with PCS 6 months after mTBI, applying divergent classification methods. ⋯ Applying the divergent classification methods resulted in a different set of predictors being statistically significantly associated with PCS, and a different percentage of overlap with functional impairment, measured with the GOSE. In conclusion, depending on the classification method and rating score used, prevalence rates of PCS deviated considerably. For future research, consensus regarding the diagnostic criteria for PCS and the analysis of the RPQ should be reached, to enhance comparability of studies regarding PCS after mTBI.
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Journal of neurotrauma · Jun 2018
Gene Profiling of Nucleus Basalis Tau Containing Neurons in Chronic Traumatic Encephalopathy: A Chronic Effects of Neurotrauma Consortium Study.
Military personnel and athletes exposed to traumatic brain injury may develop chronic traumatic encephalopathy (CTE). Brain pathology in CTE includes intracellular accumulation of abnormally phosphorylated tau proteins (p-tau), the main constituent of neurofibrillary tangles (NFTs). Recently, we found that cholinergic basal forebrain (CBF) neurons within the nucleus basalis of Meynert (nbM), which provide the major cholinergic innervation to the cortex, display an increased number of NFTs across the pathological stages of CTE. ⋯ Specifically, downregulation of the nicotinic cholinergic receptor subunit β-2 gene (CHRNB2), monoaminergic enzymes catechol-O-methyltransferase (COMT) and dopa decarboxylase (DDC), chloride channels CLCN4 and CLCN5, scaffolding protein caveolin 1 (CAV1), cortical development/cytoskeleton element lissencephaly 1 (LIS1), and intracellular signaling cascade member adenylate cyclase 3 (ADCY3) was observed in pS422-immunreactive nbM neurons in CTE patients. By contrast, upregulation of calpain 2 (CAPN2) and microtubule-associated protein 2 (MAP2) transcript levels was found in Stage IV CTE patients. These single-population data in vulnerable neurons indicate alterations in gene expression associated with neurotransmission, signal transduction, the cytoskeleton, cell survival/death signaling, and microtubule dynamics, suggesting novel molecular pathways to target for drug discovery in CTE.
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Journal of neurotrauma · Jun 2018
Making Football Safer: Assessing the Current National Football League Policy on the Type of Helmets Allowed on the Playing Field.
In an effort to reduce concussions in football, a helmet safety-rating system was developed in 2011 that rated helmets based on their ability to reduce g-forces experienced by the head across a range of impact forces measured on the playing field. Although this was considered a major step in making the game safer, the National Football League (NFL) continues to allow players the right to choose what helmet to wear during play. This prompted us to ask: What helmets do NFL players wear and does this helmet policy make the game safer? Accordingly, we identified the helmets worn by nearly 1000 players on Week 13 of the 2015-2016 season and Week 1 of the 2016-2017 season. ⋯ Using a helmet-to-helmet impactor, we found that the g-forces experienced in the highest safety-rated helmets were roughly 30% less than that for the lowest safety-rated helmets. These results suggest that the current NFL helmet policy puts players at increased risk of receiving a concussion as many players are wearing low safety-rated helmets, which transmits more energy to the brain than higher safety-rated helmets, following collision. Thus, to reduce concussions, the NFL should mandate that players only wear helmets that receive the highest safety rating.
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Journal of neurotrauma · Jun 2018
Reduced Functional Connectivity in Adults with Persistent Post-Concussion Symptoms: A Functional Near-Infrared Spectroscopy Study.
Concussion, or mild traumatic brain injury (mTBI), accounts for ∼80% of all TBIs across North America. The majority of mTBI patients recover within days to weeks; however, 14-36% of the time, acute mTBI symptoms persist for months or even years and develop into persistent post-concussion symptoms (PPCS). There is a need to find biomarkers in patients with PPCS, to improve prognostic ability and to provide insight into the pathophysiology underlying chronic symptoms. ⋯ Specifically, we aimed to identify cortical communication patterns in prefrontal and motor areas during rest and task, in adult patients with persistent symptoms. We found that (1) the PPCS group showed reduced connectivity compared with healthy controls, (2) increased symptom severity correlated with reduced coherence, and (3) connectivity differences were best distinguishable during task and in particular during the working memory task (n-back task) in the right and left dorsolateral prefrontal cortex (DLPFC). These data show that reduced brain communication may be associated with the pathophysiology of mTBI and that fNIRS, with a relatively simple acquisition paradigm, may provide a useful biomarker of this injury.
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Journal of neurotrauma · Jun 2018
The Effects of Sex Differences and Hormonal Contraception on Outcomes after Collegiate Sports-Related Concussion.
There is conflicting evidence regarding whether females are more adversely affected after concussion than males. Further, recent research suggests that hormonal contraceptive (HC) use may affect symptom severity and duration post-concussion. The objective of this study was to examine the effects of sex and HC use on outcomes following concussion among collegiate varsity athletes. ⋯ Among females, non-HC users demonstrated higher symptom severity than HC users (F[1,47] = 5.142, p < 0.05, d = 0.70). No significant differences between female HC users and non-HC users on LOR were observed. This study provides evidence for differential concussion outcomes between male and female collegiate athletes and between HC users and nonusers among females.