Journal of neurotrauma
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Journal of neurotrauma · Jun 2008
Characterizing white matter damage in rat spinal cord with quantitative MRI and histology.
ABSTRACT Diffusion tensor imaging (DTI) and quantitative T(2) magnetic resonance imaging (MRI) were used to characterize ex vivo the white matter damage at 3 and 8 weeks following dorsal column transection (DC Tx) injury at the cervical level C5 of rat spinal cords. Luxol Fast Blue (LFB) and myelin basic protein (MBP) staining was used to assess myelin damage, and neurofilament-H in combination with neuron specific beta-III-tubulin (NF/Tub) staining was used to assess axonal damage. Average values of myelin water fraction (MWF), fractional anisotropy (FA), longitudinal diffusivity (D(long)), transverse diffusivity (D(trans)), and average diffusivity (D(ave)) were calculated in the fasciculus gracilis, fasciculus cuneatus, and the dorsal corticospinal tract (CST) 5 mm cranial, as well as 5 and 10 mm caudal to injury and correlated with histology. ⋯ Both MWF and D(trans) showed significant correlation with LFB staining at 3 weeks (0.64 and -0.49, respectively) and 8 weeks post-injury (0.88 and -0.71, respectively). Both D(long) and FA correlated significantly with NF/Tub staining at 3 weeks post-injury (0.78 and 0.64, respectively), while only D(long) displayed significant correlation 8 weeks post-injury (0.58 and 0.33, respectively). This study demonstrates that quantitative MRI can accurately characterize white matter damage in DC Tx model of injury in rat spinal cord.
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Journal of neurotrauma · Jun 2008
Multicenter StudyProgression of traumatic intracerebral hemorrhage: a prospective observational study.
ABSTRACT Preliminary evidence has shown that intracerebral hemorrhages, either spontaneous (sICH) or traumatic (tICH) often expand over time. An association between hemorrhage expansion and clinical outcomes has been described for sICH. The intent of this prospective, observational study was to characterize the temporal profile of hemorrhage progression, as measured by serial computed tomography (CT) scanning, with the aim of better understanding the natural course of hemorrhage progression in tICH. ⋯ This study demonstrates that tICH expansion between the baseline and 24-h CT scans occurred in approximately half of the subjects. The earlier after injury that the initial CT scan is obtained, the greater is the likelihood that the hematoma will expand on subsequent scans. The time frame during which hemorrhagic expansion occurs provides an opportunity for early intervention to limit a process with adverse prognostic implications.
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Journal of neurotrauma · Jun 2008
Effects of Glasgow Outcome Scale misclassification on traumatic brain injury clinical trials.
The Glasgow Outcome Scale (GOS) is the primary endpoint for efficacy analysis of clinical trials in traumatic brain injury (TBI). Accurate and consistent assessment of outcome after TBI is essential to the evaluation of treatment results, particularly in the context of multicenter studies and trials. The inconsistent measurement or interobserver variation on GOS outcome, or for that matter, on any outcome scales, may adversely affect the sensitivity to detect treatment effects in clinical trial. ⋯ The magnitude of such influence not only depends on the size of the misclassification, but also on the magnitude of the treatment effect. In conclusion, nondifferential misclassification directly reduces the power of finding the true treatment effect. An awareness of this procedural error and methods to reduce misclassification should be incorporated in TBI clinical trials.
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Journal of neurotrauma · Jun 2008
Fluctuations in cortical synchronization in pediatric traumatic brain injury.
Traumatic brain injury (TBI) is the leading cause of death and acquired disability in the pediatric population worldwide. We hypothesized that electroencephalography (EEG) synchrony and its temporal variability, analyzed during the acute phase following TBI, would be altered from that of normal children and as such would offer insights into TBI pathophysiology. Seventeen pediatric patients with mild to severe head injury admitted to a pediatric critical care unit were recruited along with 10 age- and gender-matched controls. ⋯ The temporal variability of phase synchronization among EEG electrodes increased as patients recovered and emerged from coma (p < 0.001). This temporal variability correlated with outcome (Pearson coefficient of 0.74) better than the worst Glasgow Coma Scale score, length of coma, or extent of injury on CT scan. This represents a novel approach in the evaluation of TBI in children.
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Journal of neurotrauma · Jun 2008
Efficacy of progesterone following a moderate unilateral cortical contusion injury.
Traumatic brain injury (TBI) results in an accumulation of edema and loss of brain tissue. Progesterone (PROG) has been reported to reduce edema and cortical tissue loss in a bilateral prefrontal cortex injury. This study tests the hypothesis that PROG is neuroprotective following a unilateral parietal cortical contusion injury (CCI). ⋯ Group IV received two additional injections (4 mg/kg on day 5; 2 mg/kg on day 6). PROG failed to alter both cortical edema and tissue sparing at any dose. Failure to modify two major sequelae associated with TBI brings into question the clinical usefulness of PROG as an effective treatment for all types of brain injury.