Journal of neurotrauma
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Journal of neurotrauma · Jan 2010
Neurometabolic changes in the acute phase after sports concussions correlate with symptom severity.
Sports concussion is a major problem that affects thousands of people in North America every year. Despite negative neuroimaging findings, many athletes display neurophysiological alterations and post-concussion symptoms such as headaches and sensitivity to light and noise. It is suspected that neurometabolic changes may underlie these changes. ⋯ No changes were observed in the hippocampus. Furthermore, the metabolic changes in M1 correlated with self-reported symptom severity despite equivalent neuropsychological performance. These results confirm cortical neurometabolic changes in the acute post-concussion phase, and demonstrate for the first time a correlation between subjective self-reported symptoms and objective physical changes that may be related to increased vulnerability of the concussed brain.
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Magnetic resonance imaging (MRI) is widely used to evaluate the consequences of traumatic brain injury (TBI) in both experimental and clinical studies. Improved assessment of experimental TBI using the same methods as those used in clinical investigations would help to translate laboratory research into clinical advances. Here our goal was to characterize lateral fluid percussion-induced TBI, with special emphasis on differentiating the contused cortex from the pericontusional subcortical tissue. ⋯ At the same site, NAA/Cr was decreased and Lac/Cr elevated during the first week after TBI. In the ipsilateral subcortical area, NAA/Cr was markedly decreased and Lac/Cr was elevated during the first week, although MRI showed no evidence of edema, suggesting that (1)H-MRS detected "invisible" damage. (1)H-MRS combined with MRI may improve the detection of brain injury. Extensive assessments of animal models may increase the chances of developing successful neuroprotective strategies.
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Journal of neurotrauma · Jan 2010
Brain natriuretic peptide improves long-term functional recovery after acute CNS injury in mice.
There is emerging evidence to suggest that brain natriuretic peptide (BNP) is elevated after acute brain injury, and that it may play an adaptive role in recovery through augmentation of cerebral blood flow (CBF). Through a series of experiments, we tested the hypothesis that the administration of BNP after different acute mechanisms of central nervous system (CNS) injury could improve functional recovery by improving CBF. C57 wild-type mice were exposed to either pneumatic-induced closed traumatic brain injury (TBI) or collagenase-induced intracerebral hemorrhage (ICH). ⋯ After ICH, mRNA polymerase chain reaction (PCR) and histochemical staining were performed during the acute injury phase (<24 h) to determine the effects on inflammation. Following TBI and ICH, administration of hBNP was associated with improved functional performance as assessed by rotorod and Morris water maze latencies (p < 0.01). CBF was increased (p < 0.05), and inflammatory markers (TNF-alpha and IL-6; p < 0.05), activated microglial (F4/80; p < 0.05), and neuronal degeneration (Fluoro-Jade B; p < 0.05) were reduced in mice receiving hBNP. hBNP improves neurological function in murine models of TBI and ICH, and was associated with enhanced CBF and downregulation of neuroinflammatory responses. hBNP may represent a novel therapeutic strategy after acute CNS injury.
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Journal of neurotrauma · Jan 2010
Multicenter Study Clinical TrialClinical algorithm for improved prediction of ambulation and patient stratification after incomplete spinal cord injury.
The extent of ambulatory recovery after motor incomplete spinal cord injury (miSCI) differs considerably amongst affected persons. This makes individual outcome prediction difficult and leads to increased within-group variation in clinical trials. The aims of this study on subjects with miSCI were: (1) to rank the strongest single predictors and predictor combinations of later walking capacity; (2) to develop a reliable algorithm for clinical prediction; and (3) to identify subgroups with only limited recovery of walking function. ⋯ For individuals with paraparesis, prediction was less distinct, mainly due to low prediction rates for individuals with poor walking outcome. A clinical algorithm was generated that allowed for the identification of a subgroup composed of individuals with tetraparesis and poor ambulatory recovery. These data provide evidence that a combination of predictors enables a reliable prediction of walking function and early patient stratification for clinical trials in miSCI.
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Journal of neurotrauma · Jan 2010
Effect of secondary insults upon aquaporin-4 water channels following experimental cortical contusion in rats.
Although secondary insults of hypoxia and hypotension (HH) are generally considered to cause fulminant brain edema in traumatic brain injury (TBI), the combined effect of TBI with HH on brain edema and specifically the expression of aquaporin-4 (AQP4) have not been fully elucidated. The goal of this study was to document the effect of secondary insults on brain water, AQP4 expression, electrolytes, and blood-brain barrier (BBB) permeability during the acute stage of edema development. ⋯ Moreover, a significant reduction of upregulation on AQP4 expression was observed in trauma, coupled with a mild secondary insult of hypoxia hypotension. These findings indicate that a secondary insult following CCI at 5 h post injury worsens brain edema, disrupts ionic homeostasis, and blunts the normal upregulation of AQP4 that occurs after trauma, suggesting that the blunting of AQP4 may contribute to the detrimental effects of secondary insults.