Journal of neurotrauma
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Journal of neurotrauma · Feb 2016
Transition from initial hypoactivity to hyperactivity in cortical layer V pyramidal neurons following traumatic brain injury in vivo.
Traumatic brain injury (TBI) often results in structural damage and a loss of neurons that is commonly accompanied by early changes in neuronal electrical activity. Loss of neuronal activity has been hypothesized to contribute to post-traumatic epileptogenesis through the regulation of homeostatic plasticity. The existence of activity loss in cortical neurons after TBI and its subsequent transition into hyperactivity over time is not well characterized, however, particularly in models of TBI in vivo. ⋯ The firing frequencies recovered to the normal level at 1 day and 7 days post-CCI, but became significantly higher at 3 days and 14 days post-CCI. The results suggest that TBI caused initial loss of activity in neurons of the perilesional cortical region, which was followed by compensatory recovery and enhancement of activity. These time-dependent changes in neuronal activity may contribute to the development of hyperexcitability through homeostatic activity regulation.
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Journal of neurotrauma · Feb 2016
Cavum Septi Pellucidi in Symptomatic Former Professional Football Players.
Post-mortem studies reveal a high rate of cavum septi pellucidi (CSP) in chronic traumatic encephalopathy (CTE). It remains, however, to be determined whether or not the presence of CSP may be a potential in vivo imaging marker in populations at high risk to develop CTE. The aim of this study was to evaluate CSP in former professional American football players presenting with cognitive and behavioral symptoms compared with noncontact sports athletes. ⋯ In addition, a greater length of CSP was associated with decreased performance on a list learning task (Neuropsychological Assessment Battery List A Immediate Recall, p = 0.04) and decreased test scores on a measure of estimate verbal intelligence (Wide Range Achievement Test Fourth Edition Reading Test, p = 0.02). Given the high prevalence of CSP in neuropathologically confirmed CTE in addition to the results of this study, CSP may serve as a potential early in vivo imaging marker to identify those at high risk for CTE. Future research is needed to investigate the pathomechanism underlying the development of CSP after repetitive head impacts, and its potential association with neuropathologically confirmed CTE.
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Journal of neurotrauma · Feb 2016
Acute Alcohol Intoxication in Patients with Mild Traumatic Brain Injury: Characteristics, Recovery and Outcome.
A substantial number of patients (30% to 50%) sustains a mild traumatic brain injury (mTBI) while they are under the influence of alcohol. An acute alcohol intoxication (AAI) at the time of injury has been subject of research in severe TBI, but little is known about the relation between AAI and mTBI. This study aimed to describe the characteristics of this intoxicated subgroup and evaluate recovery and outcome in comparison to sober mTBI patients. ⋯ The intoxicated group was assessed with a lower GCS score and had a higher hospital admission rate. However, at 2 weeks post-injury, intoxicated patients reported less complaints than the non-alcohol group and showed a better recovery at 6 months (average GOSE scores 7 vs. 7.3; p = 0.030). We conclude that AAI in mTBI represents a characteristically different group, which has implications for prevention measures, as well as the course of recovery.
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Journal of neurotrauma · Feb 2016
Thinner cortex in collegiate football players with, but not without, a self-reported history of concussion.
Emerging evidence suggests that a history of sports-related concussions can lead to long-term neuroanatomical changes. The extent to which similar changes are present in young athletes is undetermined at this time. Here, we tested the hypothesis that collegiate football athletes with (n = 25) and without (n = 24) a self-reported history of concussion would have cortical thickness differences and altered white matter integrity relative to healthy controls (n = 27) in fronto-temporal regions that appear particularly susceptible to traumatic brain injury. ⋯ Further, football athletes with a history of concussion had significantly thinner cortex in the right central sulcus and precentral gyrus relative to football athletes without a history of concussion (p = 0.03, d = -0.71). No differences were observed between football athletes without a history of concussion and healthy controls. These results suggest that previous concussions, but not necessarily football exposure, may be associated with cortical thickness differences in collegiate football athletes.
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N-acetylaspartate (NAA) is an amino acid derivative primarily located in the neurons of the adult brain. The function of NAA is incompletely understood. Decrease in brain tissue NAA is presently considered symptomatic and a potential biomarker of acute and chronic neuropathological conditions. ⋯ Here, we show that the temporal profile of microdialysate eNAA was characterized by highest levels in the earliest time-points post-injury, followed by a steady decline; beyond 70 h post-injury, average levels were 40% lower than those measured in non-TBI patients. There was a significant inverse correlation between concentrations of eNAA and pyruvate; eNAA showed significant positive correlations with glycerol and the lactate/pyruvate (L/P) ratio measured in microdialysates. The results of this on-going study suggest that changes in eNAA after TBI relate to the release of intracellular components, possibly due to neuronal death or injury, as well as to adverse brain energy metabolism.