Journal of neurotrauma
-
Journal of neurotrauma · Apr 2014
Physiological Complexity of Acute Traumatic Brain Injury in patients treated with a Brain Oxygen Protocol: Utility of Symbolic Regression (SR) in Predictive Modeling of a Dynamical System.
Predictive modeling of emergent behavior, inherent to complex physiological systems, requires the analysis of large complex clinical data streams currently being generated in the intensive care unit. Brain tissue oxygen protocols have yielded outcome benefits in traumatic brain injury (TBI), but the critical physiological thresholds for low brain oxygen have not been established for a dynamical patho-physiological system. High frequency, multi-modal clinical data sets from 29 patients with severe TBI who underwent multi-modality neuro-clinical care monitoring and treatment with a brain oxygen protocol were analyzed. ⋯ The SR model of TBI is generalizable to known physical laws. This increase in entropy reduces uncertainty and improves predictive capacity. SR is an appropriate computational framework to enable future smart monitoring devices.
-
Journal of neurotrauma · Apr 2014
Post-traumatic hypoxia is associated with prolonged cerebral cytokine production, higher serum biomarker levels and poor outcome in patients with severe traumatic brain injury.
Secondary hypoxia is a known contributor to adverse outcomes in patients with traumatic brain injury (TBI). Based on the evidence that hypoxia and TBI in isolation induce neuroinflammation, we investigated whether TBI combined with hypoxia enhances cerebral cytokine production. We also explored whether increased concentrations of injury biomarkers discriminate between hypoxic (Hx) and normoxic (Nx) patients, correlate to worse outcome, and depend on blood-brain barrier (BBB) dysfunction. ⋯ Elevated CSF/serum albumin quotients lasted for 5 days post-TBI and displayed similar profiles in Hx and Nx patients. We demonstrate for the first time that post-TBI hypoxia is associated with prolonged neuroinflammation, amplified extravasation of biomarkers, and poor outcome. S100 and MBP could be implemented to track the occurrence of post-TBI hypoxia, and prompt adequate treatment.
-
Journal of neurotrauma · Apr 2014
Recovery of Stress Response Coincides with Responsiveness to Voluntary Exercise after Traumatic Brain Injury.
We have recently shown that there is a heightened stress response after a mild traumatic brain injury (TBI) during the first 2 post-injury weeks. This corresponds to the same post-injury period when exercise does not increase brain-derived neurotrophic factor (BDNF) and autonomic dysfunction becomes evident with exercise. Here we determined stress and autonomic responses to voluntary and forced exercise at a post-injury time window when exercise has been found to elicit beneficial effects. ⋯ This effect was more pronounced in the TBI rats. Cardiac and temperature autonomic responses to delayed exercise also recuperated. Rats with TBI that underwent forced exercise, however, had higher core body temperatures during experimental manipulations, thus suggesting that exposure to a potent stressor facilitates responsiveness to environmental stimulations.
-
Journal of neurotrauma · Apr 2014
Temporal course of changes in gene expression suggests a cytokine-related mechanism for long-term hippocampal alteration after controlled cortical impact.
Mild traumatic brain injury (mTBI) often has long-term effects on cognitive function and social behavior. Altered gene expression may be predictive of long-term psychological effects of mTBI, even when acute clinical effects are minimal or transient. Controlled cortical impact (CCI), which causes concussive, but nonpenetrant, trauma to underlying (non-cortical) brain, resulting in persistent changes in hippocampal synaptic function, was used as a model of mTBI. ⋯ Ccl2 and Ccl7 transcripts were up-regulated within 24 h after CCI, and their elevation subsided within 1 week of injury. Other transcriptional changes occurred later and were more stable, some persisting for at least 1 month, suggesting that short-term inflammatory responses trigger longer-term alteration in the expression of genes previously associated with injury, aging, and neuronal function in the brain. These transcriptional responses to mTBI may underlie long-term changes in excitatory and inhibitory neuronal imbalance in hippocampus, leading to long-term behavioral consequences of mTBI.
-
Journal of neurotrauma · Apr 2014
Contribution of psychological trauma to outcomes after traumatic brain injury: Assaults versus sporting injuries.
Clinical research into outcomes after traumatic brain injury (TBI) frequently combines injuries that have been sustained through different causes (e.g., car accidents, assaults, and falls), the effect of which is not well understood. This study examined the contribution of injury-related psychological trauma—which is more commonly associated with specific types of injuries—to outcomes after nonpenetrating TBI in order to determine whether it may be having a differential effect in samples containing mixed injuries. Data from three groups that were prospectively recruited for two larger studies were compared: one that sustained a TBI as a result of physical assaults (i.e., psychologically traumatizing) and another as a result of sporting injuries (i.e., nonpsychologically traumatizing), as well as an orthopedic control group (OC). ⋯ The TBI(assault) group reported significantly poorer psychosocial and emotional outcomes and higher rates of litigation (criminal rather than civil) than both the TBI(sport) and OC groups approximately 6 months postinjury, but there were no differences in the cognitive or functional outcomes of the three groups. The findings suggest that the cause of a TBI may assist in explaining some of the differences in outcomes of people who have seemingly comparable injuries. Involvement in litigation and the cause of an injury may also be confounded, which may lead to the erroneous conclusion that litigants have poorer outcomes.