Journal of neurotrauma
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Journal of neurotrauma · Jun 2015
Comparative StudyLactate: Brain Fuel in Human Traumatic Brain Injury. A Comparison to Normal Healthy Control Subjects.
We evaluated the hypothesis that lactate shuttling helps support the nutritive needs of injured brains. To that end, we utilized dual isotope tracer [6,6-(2)H2]glucose, that is, D2-glucose, and [3-(13)C]lactate techniques involving arm vein tracer infusion along with simultaneous cerebral (arterial [art] and jugular bulb [JB]) blood sampling. Traumatic brain injury (TBI) patients with nonpenetrating brain injuries (n=12) were entered into the study following consent of patients' legal representatives. ⋯ Comparisons of isotopic enrichments of lactate oxidation from infused [3-(13)C]lactate tracer and (13)C-glucose produced during hepatic and renal gluconeogenesis (GNG) showed that 75-80% of (13)CO2 released into the JB was from lactate and that the remainder was from the oxidation of glucose secondarily labeled from lactate. Hence, either directly as lactate uptake, or indirectly via GNG, peripheral lactate production accounted for ∼70% of carbohydrate (direct lactate uptake+uptake of glucose from lactate) consumed by the injured brain. Undiminished cerebral lactate fractional extraction and uptake suggest that arterial lactate supplementation may be used to compensate for decreased CMRgluc following TBI.
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Journal of neurotrauma · Jun 2015
Observational StudyImpact of depression and posttraumatic stress disorder on functional outcome and health-related quality of life of patients with mild traumatic brain injury.
The impact of disability following traumatic brain injury (TBI), assessed by functional measurement scales for TBI or by health-related quality of life (HRQoL), may vary because of a number of factors, including presence of depression or post-traumatic stress disorder (PTSD). The aim of this study was to assess prevalence and impact of depression and PTSD on functional outcome and HRQoL six and 12 months following mild TBI. We selected a sample of 1919 TBI patients who presented to the emergency department (ED) followed by either hospital admission or discharge to the home environment. ⋯ Living alone was an independent predictor of depression and/or PTSD at six- and 12-month follow-up. Depression and PTSD were associated with a significantly decreased functional outcome (measured with Glasgow Outcome Scale Extended) and HRQoL (measured using the SF-36 and the PQoL). We conclude that depression and/or PTSD are relatively common in our sample of TBI patients and associated with a considerable decrease in functional outcome and HRQoL.
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Journal of neurotrauma · Jun 2015
Long-lasting suppression of acoustic startle response following mild traumatic brain injury.
Acoustic startle response (ASR) is a defensive reflex that is largely ignored unless greatly exaggerated. ASR is suppressed after moderate and severe traumatic brain injury (TBI), but the effect of mild TBI (mTBI) on ASR has not been investigated. Because the neural circuitry for ASR resides in the pons in all mammals, ASR may be a good measure of brainstem function after mTBI. ⋯ In contrast to the suppression of ASR, working memory impairment was transient; memory was impaired 1 and 7 days after injury, but recovered by 21 days. The long-lasting suppression of ASR suggests long-term dysfunction of brainstem neural circuits at a time when forebrain neural circuits responsible for spatial working memory have recovered. These results have important implications for return-to-activity decisions because recovery of cognitive impairments plays an important role in these decisions.
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Journal of neurotrauma · Jun 2015
Endogenous neural stem/progenitor cells stabilize the cortical microenvironment following traumatic brain injury.
Although a myriad of pathological responses contribute to traumatic brain injury (TBI), cerebral dysfunction has been closely linked to cell death mechanisms. A number of therapeutic strategies have been studied in an attempt to minimize or ameliorate tissue damage; however, few studies have evaluated the inherent protective capacity of the brain. Endogenous neural stem/progenitor cells (NSPCs) reside in distinct brain regions and have been shown to respond to tissue damage by migrating to regions of injury. ⋯ Two weeks after CCI injury, mice deficient in NSPCs had reduced neuronal survival in the perilesional cortex and fewer Iba-1-positive and glial fibrillary acidic protein-positive glial cells but increased glial hypertrophy at the injury site. These findings suggest that the presence of NSPCs play a supportive role in the cortex to promote neuronal survival and glial cell expansion after TBI injury, which corresponds with improvements in motor function. We conclude that enhancing this endogenous response may have acute protective roles after TBI.
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Journal of neurotrauma · Jun 2015
Functional Near-Infrared Spectroscopy Reveals Reduced Inter-hemispheric Cortical Communication Following Pediatric Concussion.
Concussion, or mild traumatic brain injury (mTBI), is a growing concern, especially among the pediatric population. By age 25, as many as 30% of the population are likely to have had a concussion. Many result in long-term disability, with some evolving to postconcussion syndrome. ⋯ Pediatric patients (ages 12-18) had symptoms for 31-473 days, compared to controls, who have not had reported a previous concussion. We detected differences between patients and controls in coherence between the contralateral motor cortices using measurements of total hemoglobin and oxy-hemoglobin with a p<0.01 (n=8, control; n=12 mTBI). Given the critical need for a quantitative biomarker for recovery after a concussion, we present these data to highlight the potential of fNIRS coupled with interhemispheric coherence analysis as a biomarker of concussion injury.