Articles: brain-injuries.
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Journal of neurotrauma · Oct 1994
Lateral cortical impact injury in rats: pathologic effects of varying cortical compression and impact velocity.
Direct lateral cortical impact through the intact leptomeninges using a pneumatically driven piston produces increasingly severe pathophysiologic derangements with increasing cortical deformation. We studied the histopathologic correlates of cortical impact injury produced by 2 mm, 2.5 mm, and 3 mm deformation in the rat at 5 m/sec. Additionally, the effect of impact velocity at a 2.5 mm deformation was assessed at 1 m/sec, 3 m/sec, and 5 m/sec. ⋯ Impact velocities of 1, 3, and 5 m/sec produced neuronal loss of 18.25%, 33.75%, and 48.3%, respectively. Hippocampal CA1 neuronal loss was also seen and paralleled cortical deformation and impact velocity. Cortical deformation and impact velocity are critical parameters in producing cortical contusion and must be considered when comparing results using this model.
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Hypothermia is of proven benefit in cerebral ischemia, and may be of benefit in blunt head injury. Peritoneal dialysis is a fast, effective method of inducing generalized hypothermia. ⋯ Hypothermia was associated with prompt control of temperature and intracranial pressure. Peritoneal dialysis is a useful method for inducing hypothermia in the blunt head-injured patient.
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AJNR Am J Neuroradiol · Sep 1994
Prevalence of MR evidence of diffuse axonal injury in patients with mild head injury and normal head CT findings.
To assess the prevalence of MR evidence for diffuse axonal injury at 1.5 T in patients with normal head CT findings after mild head injury. ⋯ MR shows evidence of diffuse axonal injury in some patients with normal head CT findings after mild head injury. These lesions may represent the pathologic substrate underlying the postconcussion syndrome that occurs in many patients with moderate to severe head injury.
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Critical care medicine · Sep 1994
Cerebral lactate-oxygen index in acute brain injury with acute anemia: assessment of false versus true ischemia.
To evaluate the occurrence of global cerebral ischemia in acute brain trauma with acute anemia by combined measurements of cerebral hemodynamics, oxygenation, and lactate production. ⋯ In acute brain injury with acute anemia, global cerebral ischemia is a rare finding. However, false cerebral ischemia may be frequently found, if assessed by the lactate-oxygen index, because the denominator of the index (the arteriojugular oxygen content difference) frequently decreases as a function of decreasing hemoglobin, thus yielding false calculated ischemic high values for lactate-oxygen index despite normal cerebral oxygenation and lactate production.
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Recent work suggests that increased intracranial pressure (ICP) following brain injury and shock is related to increased central venous pressure (CVP) following resuscitation. ⋯ These data suggest that brain edema formation in the injured hemisphere is related to MAP and not CVP, but variability in MAP accounts for only 29% of the variability in CWC and ICP, suggesting the importance of factors other than hydrostatic pressure in determining the amount of edema and the ICP after brain injury. Previous work demonstrating the significant correlation of polymorphonuclear leukocyte infiltration with ICP (r = 0.71, p < 0.001) and with CWC (r = -0.63, p < 0.001) suggests that inflammation may be one of these factors.