Journal of neurotrauma
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Journal of neurotrauma · Nov 2017
Novel Noninvasive Method of Cerebrovascular Blood Volume Assessment Using Brain Bioimpedance.
Cerebrovascular autoregulation (CAR) is the ability of vessels to modulate their tone in response to changes in pressure. As an auto-protective mechanism, CAR is critical in preventing secondary brain injury post-trauma. Monitoring of changes in cerebral blood volume might be valuable in evaluating CAR and response to various therapies. ⋯ The dz correlated with changes in ICP, CPP, and CBF (r = -0.72 to -0.88, p < 0.0001). The receiver operating characteristic for dz at different thresholds of CPP and CBF showed high impedance performance with area under the curve between 0.80-1.00 (p < 0.003) and sensitivity and specificity varying between 83%-100% and 70%-100%, respectively. Our preliminary tests show that brain bioimpedance as measured through the ocular-brain interface tracks changes in CPP and CBF with high precision and may prove to be valuable in the future in assessing changes in cerebral blood volume and CAR.
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Journal of neurotrauma · Nov 2017
Accelerated Changes in Cortical Thickness Measurements with Age in Military Service Members with Traumatic Brain Injury.
Finding objective and quantifiable imaging markers of mild traumatic brain injury (TBI) has proven challenging, especially in the military population. Changes in cortical thickness after injury have been reported in animals and in humans, but it is unclear how these alterations manifest in the chronic phase, and it is difficult to characterize accurately with imaging. We used cortical thickness measures derived from Advanced Normalization Tools (ANTs) to predict a continuous demographic variable: age. ⋯ We then used these models to predict brain age in military Service Members with TBI (n = 92) and military Service Members without TBI (n = 34). Our results show that all four models overpredicted age in Service Members with TBI, and the predicted age difference was significantly greater compared with military controls. These data extend previous civilian findings and show that cortical thickness measures may reveal an association of accelerated changes over time with military TBI.
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Journal of neurotrauma · Nov 2017
Response Inhibition Deficits and Altered Motor Network Connectivity in the Chronic Phase of Pediatric TBI.
Poor response inhibition is a hallmark of pediatric traumatic brain injury (TBI). We assessed motor response inhibition by measuring commission error rates on Simple (minimized cognitive demands) and Motivation (monetary reward) Go/No-Go tasks, comparing 17 children with chronic TBI (>1 year post-injury) and 14 matched, uninjured peers. Using resting state functional magnetic resonance imaging (fMRI), we examined between-group differences in whole-brain intrinsic connectivity of the motor network as derived from the averaged time course of bilateral primary motor cortex seeds, to identify regions of interest (ROIs) for brain-behavior correlations. ⋯ In adolescents with TBI, lower motor network to left caudate connectivity correlated with poorer Simple task performance; lower motor network to right caudate connectivity correlated with poorer Simple and Motivation task performance. No significant brain-behavior relationships existed among controls. These results are consistent with previous pediatric TBI literature and suggest that disrupted intrinsic connectivity of a corticostriatal motor network may contribute to response inhibition deficits.
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Journal of neurotrauma · Nov 2017
Vitronectin regulates the fibrinolytic system during the repair of cerebral cortex in stab-wounded mice.
Vitronectin (VN), one of the serum proteins, is known to be involved in the regulation of blood coagulation, fibrinolysis, and cell migration. It has been proposed that the regulation of fibrinolysis by VN promotes the blood-brain barrier (BBB) recovery from brain injuries such as traumatic injury and subarachnoid hemorrhage. The effects of VN on fibrinolysis in the injured brain remain unclear, however. ⋯ The VN deficiency impaired the activity of plasminogen activator inhibitor-1, an inhibitor of the fibrinolytic system, at D3-5. Further, VN deficiency up-regulated the mRNA and protein expression levels of tissue-type plasminogen activator, and urokinase-type plasminogen activator. These results demonstrate that VN contributes to the regulation of the fibrinolytic system and recovery from BBB breakdown in the wounded brain.