Journal of neurotrauma
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Journal of neurotrauma · Aug 2007
Perfusional deficit and the dynamics of cerebral edemas in experimental traumatic brain injury using perfusion and diffusion-weighted magnetic resonance imaging.
The aim of this work was to characterize edema dynamics, cerebral blood volume, and flow alterations in an experimental model of brain trauma using quantitative diffusion and perfusion magnetic resonance imaging (MRI). Associated with an influx of water in the intracellular space 1-5 h post-trauma as demonstrated by the 40% reduction in apparent diffusion coefficient, a 70-80% reduction in cerebral blood flow was measured within the lesioned region. Transient hypoperfusion (40-50%) was also observed in the non-traumatized contralateral hemisphere, although there was no evidence of edema formation. After the initial cytotoxic edema, a clear evolution toward extracellular water accumulation was observed, demonstrated by an increase in apparent diffusion coefficient.
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Journal of neurotrauma · Jul 2007
Time window for voluntary exercise-induced increases in hippocampal neuroplasticity molecules after traumatic brain injury is severity dependent.
We recently found that an exercise-induced increase in hippocampal brain-derived neurotrophic factor (BDNF) is dependent when exercise is initiated after traumatic brain injury (TBI). When voluntary exercise was delayed by 2 weeks after a mild fluid-percussion injury (FPI) in rats, an increase in BDNF and an improvement in behavioral outcome were observed. This suggests that following FPI there is a therapeutic window for the implementation of voluntary exercise. ⋯ Whereas BDNF levels significantly increased with exercise in the mild FPI rats that were exercised from PID 14 to 20, the moderate FPI rats only showed significant increases in BDNF when exercised from PID 30 to 36. In addition, moderate FPI rats that were allowed to exercise from PID 30 to 36 also exhibited significant increases in synapsin I and CREB. These results indicate that the time window for exercise-induced increases in BDNF, synapsin I, and CREB is dependent on injury severity.
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The response of trauma systems in rural areas is uncertain since distances between injury scenes and trauma care are considerable. Timely arrival at definitive care is critical for persons with traumatic brain injury (TBI) since secondary damage can occur during the hours following injury. We evaluated how the implementation of a trauma system in a predominately rural state affected the triage of TBI patients and their risk for mortality. ⋯ Following implementation of the trauma system, patients treated in Level I or II facilities were older (p = 0.019), more often had multiple injuries (p = 0.0002), and had more severe TBI (p = 0.008). After controlling for confounders, transferred patients and those directly admitted were less likely to die in 72 h in the post-system than the pre-system (odds ratio [OR] = 0.56, 95% confidence interval (CI) = 0.36, 0.88; OR = 0.50, 95% CI = 0.32, 0.79). Implementation of the Iowa trauma system seems to have led to more appropriate triage and transport for TBI patients, and this likely contributed to reduced in-hospital mortality.
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Journal of neurotrauma · Jul 2007
Comparative StudyMulti-modal magnetic resonance imaging alterations in two rat models of mild neurotrauma.
Magnetic resonance imaging (MRI) is increasingly used in the assessment of the severity and progression of neurotrauma. We evaluated temporal and regional changes after mild fluid percussion (FPI) and controlled cortical impact (CCI) injury using T2-weighted-imaging (T2WI) and diffusion-weighted imaging (DWI) MRI over 7 days. Region of interest analysis of brain areas distant to the injury site (such as the hippocampus, retrosplenial and piriform cortices, and the thalamus) was undertaken. ⋯ Histological assessment of FPI animals revealed numerous shrunken cells in the hippocampus and thalamus, but other regions showed little damage. Increased immunohistochemical staining for microglia and astroglia at 7 days post-injury was greater in FPI animals within the affected brain regions. In summary, traumatic brain injury is less severe in mild CCI than FPI, based on the temporal events assessed with MRI.
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Journal of neurotrauma · Jul 2007
Decompressive craniectomy for traumatic brain injury: patient age and outcome.
The overall degree by which different patients may benefit from decompressive craniectomy (DC) remains controversial. In particular, the prognostic value of age has been investigated by very few studies. Many authors state there is no significant benefit in performing a DC in severe head injury after a certain age limit, with most placing the limit at 30-50 years of age. ⋯ Logistic regression analysis showed age as an independent predictive factor to outcome (p = 0.005). A difference in outcome exists among patients over 65 and patients aged