Journal of neurotrauma
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We used magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) to evaluate the effects of boxing on brain structure and cognition in 10 boxers (8 retired, 2 active; mean age = 45.7 years; standard deviation [SD] = 9.71) and 9 participants (mean age = 43.44; SD = 9.11) in noncombative sports. Evans Index (maximum width of the anterior horns of the lateral ventricles/maximal width of the internal diameter of the skull) was significantly larger in the boxers (F = 4.52; p = 0.050; Cohen's f = 0.531). Word list recall was impaired in the boxers (F(1,14) = 10.70; p = 0.006; f = 0.84), whereas implicit memory measured by faster reaction time (RT) to a repeating sequence of numbers than to a random sequence was preserved (t = 2.52; p < 0.04). ⋯ Years of boxing was negatively related to the number of words consistently recalled over trials (r = -0.74; p = 0.02), delayed recall (r = -0.83; p = 0.003), and serial RT (r = 0.66; p = 0.05). We conclude that microstructural integrity of white matter tracts is related to declarative memory and response speed in boxers and to the extent of boxing exposure. Implications for chronic traumatic encephalopathy are discussed.
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Hyponatremia is frequent in patients suffering from traumatic brain injury, subarachnoid hemorrhage, or following intracranial procedures, with approximately 20% having a decreased serum sodium concentration to <125 mmol/L. The pathophysiology of hyponatremia in neurotrauma is not completely understood, but in large part is explained by the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). The abnormal water and/or sodium handling creates an osmotic gradient promoting the shift of water into brain cells, thereby worsening cerebral edema and precipitating neurological deterioration. ⋯ Current options for the management of hyponatremia include fluid restriction, hypertonic saline, mineralocorticoids, and osmotic diuretics. However, the recent development of vasopressin receptor antagonists provides a more physiological tool for the management of excess water retention and consequent hyponatremia, such as occurs in SIADH. This review summarizes the existing literature on the pathophysiology, clinical features, and management of hyponatremia in the setting of neurotrauma.
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Journal of neurotrauma · Apr 2016
Clinical TrialImprovement of neuroenergetics by hypertonic lactate therapy in patients with traumatic brain injury is dependent on baseline cerebral lactate/pyruvate ratio.
Energy dysfunction is associated with worse prognosis after traumatic brain injury (TBI). Recent data suggest that hypertonic sodium lactate infusion (HL) improves energy metabolism after TBI. ⋯ In contrast, CMD glucose increase was independent from baseline CBF (coefficient +0.13 [0.04-0.21] mmol/L when global CBF was <32.5 mL/100 g/min vs. +0.09 [0.04-0.14] mmol/L at normal CBF, both p < 0.005) and systemic glucose. Our data suggest that improvement of brain energetics upon HL seems predominantly dependent on baseline cerebral metabolic state and support the concept that CMD LPR - rather than CBF - could be used as a diagnostic indication for systemic lactate supplementation following TBI.
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Journal of neurotrauma · Apr 2016
Manganese-Enhanced MRI as a diagnostic and dispositional tool after mild-moderate blast TBI.
Traumatic brain injury (TBI) caused by explosive munitions, known as blast TBI, is the signature injury in recent military conflicts in Iraq and Afghanistan. Diagnostic evaluation of TBI, including blast TBI, is based on clinical history, symptoms, and neuropsychological testing, all of which can result in misdiagnosis or underdiagnosis of this condition, particularly in the case of TBI of mild-to-moderate severity. Prognosis is currently determined by TBI severity, recurrence, and type of pathology, and also may be influenced by promptness of clinical intervention when more effective treatments become available. ⋯ Interestingly, when mice were protected with a polycarbonate body shield during blast exposure, the marked increase in contrast was prevented. We conclude that manganese uptake can serve as a quantitative biomarker for TBI and that MEMRI is a minimally-invasive quantitative approach that can aid in the accurate diagnosis and management of blast TBI. In addition, the prevention of the increased uptake of manganese by body protection strongly suggests that the exposure of an individual to blast risk could benefit from the design of improved body armor.
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Journal of neurotrauma · Apr 2016
Repetitive mild traumatic brain injury in the developing brain: effects on long-term functional outcome and neuropathology.
Although accumulating evidence suggests that repetitive mild TBI (rmTBI) may cause long-term cognitive dysfunction in adults, whether rmTBI causes similar deficits in the immature brain is unknown. Here we used an experimental model of rmTBI in the immature brain to answer this question. Post-natal day (PND) 18 rats were subjected to either one, two, or three mild TBIs (mTBI) or an equivalent number of sham insults 24 h apart. ⋯ In conclusion, mTBI results in traumatic axonal injury and microglial activation in the immature brain with repeated impact exacerbating axonal injury. The rmTBI in the immature brain leads to long-term associative learning deficit in adulthood. Defining the mechanisms damage from rmTBI in the developing brain could be vital for identification of therapies for children.