Journal of neurotrauma
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Journal of neurotrauma · Jun 2007
Statistical image analysis of cerebral glucose metabolism in patients with cognitive impairment following diffuse traumatic brain injury.
The aim of this study was to explore the regional cerebral glucose metabolism (rCM) in patients with chronic stage traumatic brain injury (TBI) compared with normal controls. We also investigated the relationship between regional cerebral glucose metabolism and cognitive function. We performed 2-[(18)F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) study using statistical parametric mapping (SPM) analysis in 36 diffuse axonal injury (DAI) patients (mean age +/- SD, 36.3 +/- 9.8 years). ⋯ DAI may induce functional disconnection and decreased neuronal activity, and finally lead to diffuse glucose hypometabolism. Low full-scale IQ scores may be related to significantly different underlying cognitive impairment. In supporting cognitive function following TBI, which showed diffuse cerebral metabolic reduction compared with normal controls, medial prefrontal cortex and anterior cingulate cortex may be an important component.
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Journal of neurotrauma · Jun 2007
Diffusion tensor imaging predicts hyperacute spinal cord injury severity.
Experimental strategies that focus on ventral white matter (VWM) preservation during the hyperacute phase hold great potential for our improved understanding of functional recovery following traumatic spinal cord injury (SCI). Critical comparisons of human SCI to rapidly accumulating data derived from rodent models are limited by a basic lack of in vivo measures of subclinical pathophysiologic changes and white matter damage in the spinal cord. Spinal cord edema and intraparenchymal hemorrhage demonstrated with routine MR sequences have limited value for predicting functional outcomes in SCI animal models and in human patients. ⋯ In the hyperacute phase, relative anisotropy maps provided excellent gray-white matter contrast in all degrees of injury. In vivo DTI-derived measurements of axial diffusion differentiated between mild, moderate, and severe contusive SCI with good histological correlation. Cross-sectional regional measurements of white matter injury severity between dorsal columns and VWM varied with increasing cord displacement in a pattern consistent with spinal cord viscoelastic properties.
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Journal of neurotrauma · Jun 2007
Modeling neural injury in organotypic cultures by application of inertia-driven shear strain.
In vitro models of traumatic brain injury (TBI) are indispensable to explore the effects of mechanotrauma on neurological injury cascades and injury thresholds. This study characterizes a novel in vitro model of neural shear injury, which for the first time subjects organotypic cultures to inertia-driven shear strain. In this model, organotypic cultures preserved a high level of biological heterogeneity and spatial cytoarchitecture, while inertia-driven shear strain represented a tissue-level insult typical for closed head TBI in vivo. ⋯ Cell death in response to impact velocities of 6.6 m/sec or less was not significantly higher than baseline cell death in sham cultures (4.4 +/- 1.5%). Higher impact velocities of 8.1 and 10.4 m/sec resulted in a significant increase in cell death to 19.9 +/- 12.9% and 36.7 +/- 14.2%, respectively (p < 0.001). The neural shear injury model delivered a gradable, defined mechanotrauma and thereby provides a novel tool for investigation of biological injury cascades in organotypic cultures.
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Journal of neurotrauma · Jun 2007
Effective ICP reduction by decompressive craniectomy in patients with severe traumatic brain injury treated by an ICP-targeted therapy.
Severe traumatic brain injury (TBI) is one of the major causes of death in younger age groups. In Umeå, Sweden, an intracranial pressure (ICP) targeted therapy protocol, the Lund concept, has been used in treatment of severe TBI since 1994. Decompressive craniectomy is used as a protocol-guided treatment step. ⋯ The outcome was favorable (GOS 5-4) in 71% in the craniectomized group, and in 61% in the non-craniectomized group. Craniectomy is a useful tool in achieving a significant reduction of ICP overtime in TBI patients with progressive intracranial hypertension refractory to medical therapy. The procedure seems to have a satisfactory effect on the outcome, as demonstrated by a high rate of favorable outcome and low mortality in the craniectomized group, which did not significantly differ compared with the non-craniectomized group.
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Journal of neurotrauma · Jun 2007
Nkx2.2 expression in differentiation of oligodendrocyte precursor cells and inhibitory factors for differentiation of oligodendrocytes after traumatic spinal cord injury.
Because successful remyelination does not occur following traumatic spinal cord injury, patients suffer from long tract dysfunction. However, demyelination is followed by remyelination in early multiple sclerosis. Oligodendrocyte precursor cells constitute a large cell population in the adult mammalian central nervous system. ⋯ To assess whether environmental changes differ between these two models, mRNA expressions of various cytokines were evaluated and compared. IL-1beta and IL-6 mRNA significantly increased in the contusion-induced injury model, 6 h after the injury. These results suggest that environmental factors such as cytokines may affect Nkx2.2 expression or oligodendrocyte precursor cell differentiation in the contusion-induced spinal cord injury model.