Journal of neurotrauma
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Journal of neurotrauma · Nov 2017
A prospective transcranial Doppler ultrasound-based evaluation of the acute and cumulative effects of sport-related concussion on neurovascular coupling response dynamics.
Sport-related concussion has been shown to alter cerebral blood flow (CBF) both acutely and chronically, and may exert cumulative effects across multiple injuries. Such dysfunction may be mediated by trauma-induced deficits to CBF control mechanisms, though our understanding of these effects is limited, including dynamics of neurovascular coupling (NVC) responses (i.e., CBF responses to neurologic demand). A total of 179 junior-level contact sport athletes completed preseason testing; 42 reported never having experienced a concussion (Hx-) while 31 had endured three or more (Hx3+). ⋯ No NVC metric differences were observed between the Hx- and Hx3+ groups at preseason. Via multiple potential mechanisms, acute sport-related concussion may induce compensatory alterations in NVC response dynamics that may be related to clinical recovery. Such effects do not appear to be persistent across multiple injuries.
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Journal of neurotrauma · Nov 2017
IL-33 promotes recruitment of microglia/macrophages in response to traumatic brain injury.
Traumatic brain injury (TBI) is a devastating condition, often leading to life-long consequences for patients. Even though modern neurointensive care has improved functional and cognitive outcomes, efficient pharmacological therapies are still lacking. Targeting peripherally derived, or resident inflammatory, cells that are rapid responders to brain injury is promising, but complex, given that the contribution of inflammation to exacerbation versus improved recovery varies with time post-injury. ⋯ Astrocytes and oligodendrocytes were the main producers of IL-33. Post-TBI, brains of mice deficient in the IL-33 receptor, ST2, contained fewer microglia/macrophages in the injured region than wild-type mice and had an altered cytokine/chemokine profile in response to injury. These observations indicate that IL-33 plays a role in neuroinflammation with microglia/macrophages being cellular targets for this interleukin post-TBI.
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Journal of neurotrauma · Nov 2017
Monitoring of optimal cerebral perfusion pressure in traumatic brain injured patients using a multi-window weighting algorithm.
Methods to identify an autoregulation guided "optimal" cerebral perfusion pressure (CPPopt) for traumatic brain injury patients (TBI) have been reported through several studies. An important drawback of existing methodology is that CPPopt can be calculated only in ∼50-60% of the monitoring time. In this study, we hypothesized that the CPPopt yield and the continuity can be improved significantly through application of a multi-window and weighting calculation algorithm, without adversely affecting preservation of its prognostic value. ⋯ The relationship between ΔCPP according to the multi-window algorithm and outcome was similar to that for CPPopt calculated on the basis of a single window. In conclusion, this study validates the use of a new multi-window and weighting algorithm for significant improvement of CPPopt yield in TBI patients. This methodological improvement is essential for its clinical application in future CPPopt trials.
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Journal of neurotrauma · Nov 2017
Expression of Caspase Signaling Components in the Outer Membranes of Chronic Subdural Hematomas.
Chronic subdural hematoma (CSDH) is fundamentally treatable through surgery, although CSDH recurs in some cases. We have observed several cases of spontaneous resolution of CSDH outer membranes, including in trabecular CSDH, after trepanation surgery. In this study, we examined the expression of molecules involved in caspase signaling in CSDH outer membranes. ⋯ Thus, during the growth of CSDH outer membranes, the caspase signaling pathway may be restrained. Once the pathway is activated, gradual resolution of CSDH outer membranes may occur. Therefore, these molecules may be novel therapeutic targets for intractable CSDH.
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Journal of neurotrauma · Nov 2017
Effect of Cerebrospinal Fluid Drainage on Brain Tissue Oxygenation in Traumatic Brain Injury.
The effectiveness of cerebrospinal fluid (CSF) drainage in lowering high intracranial pressure (ICP) is well established in severe traumatic brain injury (TBI). Recently, however, the use of external ventricular drains (EVDs) and ICP monitors in TBI has come under question. The aim of this retrospective study was to investigate the effect of CSF drainage on brain tissue oxygenation (PbtO2). ⋯ During the 4 min of opened EVD, ICP decreased by 5.7 ± 0.6 mm Hg, CPP increased by 4.1 ± 1.2 mm Hg, and PbtO2 increased by 1.15 ± 0.26 mm Hg. ICP, CPP, and PbtO2 all improved with CSF drainage at ICP EVD-opening values above 25 mm Hg. Although the average PbtO2 changes were small, a clinically significant change in PbtO2 of 5 mm Hg or greater occurred in 12% of CSF drainage events, which was correlated with larger decreases in ICP, displaying a complex relationship between ICP and PbtO2 that warrants further studies.