Journal of neurotrauma
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Journal of neurotrauma · Oct 2006
Traumatic brain injury produces delay-dependent memory impairment in rats.
Memory impairment following traumatic brain injury (TBI) is common in both humans and animals. A noteworthy feature of memory dysfunction in human TBI is impaired memory performance that is dependent on the delay between initial learning and recall of information. However, previous studies of TBI-induced memory impairment in animals have failed to control for the initial amount of learning between sham and injured animals. ⋯ However, as the delay increased to 30 and 120 sec, the performance of the injured animals deteriorated (p < 0.05). These results indicate that LFP injury produces delay-dependent memory impairments in rats. This is therefore a valid model of an important feature of memory impairment in human TBI, and should be a useful addition to the available methods for assessing memory impairment and the effect of therapeutic interventions after TBI.
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Journal of neurotrauma · Oct 2006
ReviewIn vivo characterization of traumatic brain injury neuropathology with structural and functional neuroimaging.
Quantitative neuroimaging is increasingly used to study the effects of traumatic brain injury (TBI) on brain structure and function. This paper reviews quantitative structural and functional neuroimaging studies of patients with TBI, with an emphasis on the effects of diffuse axonal injury (DAI), the primary neuropathology in TBI. Quantitative structural neuroimaging has evolved from simple planometric measurements through targeted region-of-interest analyses to whole-brain analysis of quantified tissue compartments. ⋯ The functional consequences of these structural changes can be imaged with activation functional neuroimaging. Although this line of research is at an early stage, results indicate that TBI causes a more widely dispersed activation in frontal and posterior cortices. Further progress in analysis of the consequences of TBI on neural structure and function will require control of variability in neuropathology and behavior.
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Journal of neurotrauma · Oct 2006
Clinical TrialPercutaneous implantation of cerebral microdialysis catheters by twist-drill craniostomy in neurocritical patients: description of the technique and results of a feasibility study in 97 patients.
Cerebral microdialysis is increasingly used to monitor several types of neurocritical patients. This study presents the technique used in our unit for percutaneous implantation of cerebral microdialysis catheters using a small twist-drill craniostomy that can be performed in the intensive care unit (ICU). We also present the results of this technique in 89 head-injured patients and in eight patients with a malignant middle cerebral artery (MCA) infarction. ⋯ In four patients (3% of implanted catheters), follow-up computed tomography (CT) scans showed a small intracerebral blood collection (always
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Journal of neurotrauma · Oct 2006
Aspects on decompressive craniectomy in patients with traumatic head injuries.
In patients with traumatic brain injury (TBI), intracranial hypertension secondary to cerebral edema is a major problem. A last-tier treatment in these cases is decompressive craniectomy. The aim of the present retrospective investigation was to (1) study the long-time outcome in patients with traumatic head injuries with intracranial hypertension treated with decompressive craniectomy; (2) examine the effects on intracranial pressure (ICP) by the craniectomy; and (3) investigate the possible relationship between the size of the removed bone-flap and the effects on ICP. ⋯ The outcome of all patients could be assessed. The survival rate was 89%. Two patients died (both day 4 after the trauma); 68% of the patients had a favorable outcome (Glasgow Outcome Scale [GOS] score of 4 or 5); 16% were severely disabled (GOS score of 3); and one patient (5%) was left in a vegetative state.
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Journal of neurotrauma · Oct 2006
Diffusion tensor imaging in the corpus callosum in children after moderate to severe traumatic brain injury.
Diffusion tensor imaging (DTI) is a recent imaging technique that assesses the microstructure of the cerebral white matter (WM) based on anisotropic diffusion (i.e., water molecules move faster in parallel to nerve fibers than perpendicular to them). Fractional anisotropy (FA), which ranges from 0 to 1.0, increases with myelination of WM tracts and is sensitive to diffuse axonal injury (DAI) in adults with traumatic brain injury (TBI). However, previous DTI studies of pediatric TBI were case reports without detailed outcome measures. ⋯ In the TBI patients, higher FA was related to better functional outcome as measured by the dichotomized Glasgow Outcome Scale (GOS). FA also increased as a function of the area of specific regions of the corpus callosum such as the genu and splenium, and FA in the splenium was reduced with greater volume of lesions in this region. DTI may be useful in identifying biomarkers related to DAI and outcome of TBI in children.