Journal of neurotrauma
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Journal of neurotrauma · Sep 2017
Evaluation of touchscreen chambers to assess cognition in adult mice: Effect of training and mild traumatic brain injury.
Cognitive impairments are often experienced after a mild traumatic brain injury (mTBI). In the clinical arena, neuropsychological assessments are used frequently to detect cognitive deficits. Animal models of mTBI, however, rely on an assortment of behavioral tasks to assess cognitive outcome. ⋯ Alternatively, mice demonstrated some capacity to learn in the LD paradigm, but only with the easier stages of the task. The mTBI did not affect performance in the LD paradigm, however. Thus, we concluded that under the conditions presented here, the PAL and LD touchscreen tasks are not robust outcome measures for the evaluation of cognitive performance in C57BL/6 mice after a single impact-acceleration mTBI.
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Journal of neurotrauma · Sep 2017
Modeling the Long-Term Consequences of Repeated Blast-Induced Mild Traumatic Brain Injuries.
Repeated mild traumatic brain injury (rmTBI) caused by playing collision sports or by exposure to blasts during military operations can lead to late onset, chronic diseases such as chronic traumatic encephalopathy (CTE), a progressive neurodegenerative condition that manifests in increasingly severe neuropsychiatric abnormalities years after the last injury. Currently, because of the heterogeneity of the clinical presentation, confirmation of a CTE diagnosis requires post-mortem examination of the brain. ⋯ Modeling the long-term consequences of blast rmTBI in animals is especially challenging because of the complexities of blast physics and animal-to-human scaling issues. This review summarizes current knowledge about the pathobiologies of CTE and rmbTBI and discusses problems as well as potential solutions related to high-fidelity modeling of rmbTBI and determining its long-term consequences.
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Journal of neurotrauma · Sep 2017
Randomized Controlled TrialRed blood cell transfusion guided by near infrared spectroscopy in neurocritically ill patients with moderate or severe anaemia.
In neurocritically ill patients (NCPs), the use of hemoglobin level as the sole indicator for red blood cell transfusion (RBCT) can result in under- or over-transfusion. This randomized controlled trial was conducted to ascertain whether a transcranial oxygen saturation (rSO2) threshold, as measured by near-infrared spectroscopy, reduces RBCT requirements in anemic NCPs (closed traumatic brain injury, subarachnoid, or intracerebral hemorrhage), compared with a hemoglobin threshold alone. Patients with hemoglobin 70-100 g/L received RBCTs to attain an rSO2 > 60% (rSO2 arm) or to maintain hemoglobin between 85 and 100 g/L (hemoglobin arm). ⋯ There were no differences between the study arms regarding the percentage of transfused patents (59% vs. 71%; relative risk 0.83 [95% CI 0.62-1.11]), stay on neurocritical care unit (21 vs. 20 days), unfavorable Glasgow Outcome Scale scores on hospital discharge (57% vs. 71%), in-hospital mortality (6% vs. 10%), or 1 year mortality (24% vs. 24%). Among NCPs with hemoglobin concentrations of 70-85 g/L, withholding transfusion until rSO2 is <60% may result in reduced RBCs requirements compared with routinely transfusing to attain a hemoglobin level >85 g/L. Further studies are required to confirm this finding and its possible impact on clinically significant outcomes.
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Journal of neurotrauma · Sep 2017
Characterization of Differences in Functional Connectivity Associated with Close-Range Blast Exposure.
Despite the prevalence of blast injuries in recent overseas conflicts, knowledge of their impact on neural health is lacking. We have recently published work demonstrating differences in functional magnetic resonance imaging (fMRI) connectivity that were specific to close-range blast exposure (CBE), as opposed to other prevalent military-related factors. Here, we replicate this finding in an independent sample of 135 veterans, again finding that CBE, regardless of concussion, is predictive of persistent changes in brain physiology. ⋯ These findings are not consistent with expected results from damaged white matter or impaired neural function. Rather, potential biological interpretations include disrupted cerebral blood flow or impaired neurovascular coupling, which have each been observed in animal models of blast exposure. Further targeted work will be necessary to distinguish the contribution of each of these mechanisms to producing changes in brain function associated with CBE.