Journal of neurotrauma
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Journal of neurotrauma · Mar 2014
ReviewTowards objective markers of concussion in sport: a review of white matter and neurometabolic changes in the brain following sports-related concussion.
Abstract Sports-related concussion is an issue that has piqued the public's attention of late as concerns surrounding potential long-term sequelae as well as new methods of characterizing the effects of this form of injury continue to develop. For the most part, diagnosis of concussion is based on subjective clinical measures and thus is prone to under-reporting. ⋯ Our aim is to outline a variety of the approaches to concussion research that have been employed, with special attention given to the clinical considerations and acute complications attributed to concussive injury. DTI and MRS have been at the forefront of research as a result of their noninvasiveness and ease of acquisition, and hence it is thought that the use of these neuroimaging modalities has the potential to aid clinical decision making and management, including guiding return-to-play protocols.
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Journal of neurotrauma · Mar 2014
Serial Atlas-based DTI Study of Uncomplicated Mild Traumatic Brain Injury in Adults.
Abstract In this report, we applied diffusion tensor imaging (DTI) methods in 36 patients with uncomplicated mild traumatic brain injury (mTBI) and a comparison group of 37 participants with orthopedic injury. Our aim was to characterize regional and global macro- and microstructural attributes of white matter (WM), gray matter (GM), in addition to volume and diffusivity of cerebrospinal fluid (CSF) to identify and differentiate patterns of acute and short-term recovery. Given that previous DTI reports on mTBI in adults using a region-of-interest approach implicated the corona radiata (CR), corpus callosum, and hippocampus, we analyzed and quantified DTI metrics of these regions using atlas-based methods. ⋯ CR radial diffusivity was found to be elevated in the between-group comparison at baseline (mTBI1 vs. OC1), but did not differ in the within-group comparison (mTBI1 vs. mTBI2; N=19), suggesting the possible resolution of edema. Our analysis of the cross-sectional and follow-up data, which is uncorrected for multiple comparisons, demonstrates dissociation between volumetric (macrostructural) and tissue integrity (microstructural) attributes and shows the potential utility of DTI to capture transient edema in the CR.
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Journal of neurotrauma · Mar 2014
An fMRI Study of Working Memory in Youth Following Sports-related Concussion: Is it Still Working?
Abstract In children, the importance of detecting deficits after mild traumatic brain injury (mTBI) or concussion has grown with the increasing popularity of leisure physical activities and contact sports. Whereas most postconcussive symptoms (PCS) are similar for children and adults, the breadth of consequences to children remains largely unknown. To investigate the effect of mTBI on brain function, we compared working memory performance and related brain activity using blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) in 15 concussed youths and 15 healthy age-matched control subjects. ⋯ However, significant differences were noted. In particular, the observation of reduced working memory accuracy suggests that youths may be unable to engage compensatory strategies to maintain cognitive performance after mTBI. This has significant implications for safe return to daily activities, including competitive sport.
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Journal of neurotrauma · Mar 2014
Neuroprotective efficacy of a proneurogenic compound after traumatic brain injury.
Traumatic brain injury (TBI) is characterized by histopathological damage and long-term sensorimotor and cognitive dysfunction. Recent studies have reported the discovery of the P7C3 class of aminopropyl carbazole agents with potent neuroprotective properties for both newborn neural precursor cells in the adult hippocampus and mature neurons in other regions of the central nervous system. This study tested, for the first time, whether the highly active P7C3-A20 compound would be neuroprotective, promote hippocampal neurogenesis, and improve functional outcomes after experimental TBI. ⋯ Five weeks after TBI, animals treated with P7C3-A20 showed significantly increased BrdU/NeuN double-labeled neurons and improved cognitive function in the Morris water maze, compared to TBI-control animals. These results suggest that P7C3-A20 is neuroprotective and promotes endogenous reparative strategies after TBI. We propose that the chemical scaffold represented by P7C3-A20 provides a basis for optimizing and advancing new pharmacological agents for protecting patients against the early and chronic consequences of TBI.
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The pathophysiology of blast-induced traumatic brain injury (TBI) and subsequent behavioral deficits are not well understood. Unraveling the mechanisms of injury is critical to derive effective countermeasures against this form of neurotrauma. Preservation of the integrity of cellular DNA is crucial for the function and survival of cells. ⋯ A positive correlation was observed between the righting reflex time and CFD level in plasma at 2 h after blast exposure. Brain DNA damage subsequent to repeated blast was associated with decreased mitochondrial membrane potential, increased release of cytochrome C, and up-regulation of caspase-3, all of which are indicative of cellular apoptosis. Shock-wave-induced DNA damage and initiation of mitochondrial-driven cellular apoptosis in the brain after repeated blast exposures indicate that therapeutic strategies directed toward inhibition of DNA damage or instigation of DNA repair may be effective countermeasures.