Journal of neurotrauma
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Journal of neurotrauma · May 2014
Diffusion tensor imaging reveals white matter injury in a rat model of repetitive blast-induced traumatic brain injury.
Blast-induced traumatic brain injury (bTBI) is one of the most common combat-related injuries seen in U. S. military personnel, yet relatively little is known about the underlying mechanisms of injury. In particular, the effects of the primary blast pressure wave are poorly understood. ⋯ Computational statistical methods such as voxelwise analysis have shown promise in localizing and quantifying bTBI throughout the brain. In this study, we use voxelwise analysis of DTI to quantify white matter injury in a rat model of repetitive primary blast exposure. Our results show a significant increase in microstructural damage with a second blast exposure, suggesting that primary bTBI may sensitize the brain to subsequent injury.
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Journal of neurotrauma · May 2014
Observational StudyEffect of osmotherapy on optic nerve sheath diameter in patients with increased intracranial pressure.
The measurement of ocular nerve sheath diameter (ONSD) via ocular ultrasound scanning is a recent non-invasive method for intracranial pressure (ICP) assessment. Few clinical studies have assessed ONSD variations during osmotherapy for the treatment of sustained increased ICP episodes. The aim of our study was to determine the rate of ONSD variation after mannitol administration for increased ICP episodes. ⋯ The ONSD significantly decreased after mannitol infusion from 6.3 (6.1-6.7) to 5. mm (5.5-6.3) (p=0.0007). Concomitantly, the intracranial pressure decreased from 35 (32-41) to 25 (22-29) mmHg (p=0.001) and the CPP increased from 47 (50-60) to 66 (59-69) mmHg (p=0.003). The variations of ONSD appear to be an interesting parameter to evaluate the efficacy of osmotherapy for elevated ICP episodes in patients with acute brain injury.
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Journal of neurotrauma · May 2014
Comparative StudyComparison of the Effect of Minocycline and Simvastatin on Functional Recovery and Gene Expression in a Rat Traumatic Brain Injury Model.
The goal of this study was to compare the effects of minocycline and simvastatin on functional recovery and brain gene expression after a cortical contusion impact (CCI) injury. Dosage regimens were designed to provide serum concentrations in a rat model in the range obtained with clinically approved doses; minocycline 60 mg/kg q12h and simvastatin 10 mg/kg q12h for 72 h. Functional recovery was assessed using motor and spatial learning tasks and neuropathological measurements. ⋯ There was a minimal effect of simvastatin on gene expression 24 h after injury, with increasing effects at 72 h and 7 days. GOA identified a significant effect of simvastatin on inflammatory response at 72 h and 7 days. In conclusion, treatment with minocycline and simvastatin resulted in significant effects on gene expression in the brain reflecting adequate brain penetration without producing significant neurorestorative effects.
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Journal of neurotrauma · May 2014
Old dog, new tricks: the attentional set-shifting test as a novel cognitive behavioral task after controlled cortical impact injury.
Cognitive impairment associated with prefrontal cortical dysfunction is a major component of disability in traumatic brain injury (TBI) survivors. Specifically, deficits of cognitive flexibility and attentional set-shifting are present across all levels of injury severity. Though alterations in spatial learning have been extensively described in experimental models of TBI, studies investigating more complex cognitive deficits are relatively scarce. ⋯ Further, injury severity-induced deficits in ED set-shifting and stimulus reversals, as well as increases in total response error rates and total set loss errors, were observed. These novel findings demonstrate executive function and behavioral flexibility deficits in our animal model of CCI injury and provide the impetus to integrate the AST in the standard neurotrauma behavioral battery to further evaluate cognitive dysfunction after TBI. Ongoing experiments in our laboratory are assessing AST performance after pharmacological and rehabilitative therapies post-TBI, as well as elucidating possible mechanisms underlying the observed neuropsychological deficits.
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Journal of neurotrauma · May 2014
Environmental enrichment as a viable neurorehabilitation strategy for experimental traumatic brain injury.
Environmental enrichment (EE) emerged as a robust independent variable capable of influencing behavioral outcome in experimental studies after the fortuitous observation by renowned neuropsychologist Donald O. Hebb that rats raised as pets in his home performed markedly better on problem-solving tasks than those kept in the laboratory. In the subsequent years, numerous studies ensued demonstrating that EE was also capable of inducing neuroplasticity in normal (i.e., noninjured) rats. ⋯ Further, the enhancements are observed in male and female as well as adult and pediatric rats and mice. Taken together, these cumulative findings provide strong support for EE as a generalized and robust preclinical model of neurorehabilitation. However, to further enhance the model and to more accurately mimic the clinic, future studies should continue to evaluate EE during more rehabilitation-relevant conditions, such as delayed and shorter time periods, as well as in combination with other therapeutic approaches, as we have been doing for the past few years.