Acta neurochirurgica. Supplement
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Acta Neurochir. Suppl. · Jan 2000
Increased adrenomedullin in cerebrospinal fluid after traumatic brain injury in children: a preliminary report.
Adrenomedullin is a recently discovered 52-amino-acid peptide that is a potent vasodilator. Infusion of adrenomedullin increases regional cerebral blood flow and reduces infarct volume after vascular occlusion in rats. Adrenomedullin may represent an endogenous neuroprotectant since it is increased after focal brain ischemia. ⋯ All 36 case samples had an adrenomedullin concentration above the median value for the controls (1.52 fmol/ml). We conclude adrenomedullin is elevated in the CSF of children following severe TBI. We speculate that it participates in the endogenous response to cerebral hypoperfusion after TBI.
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Acta Neurochir. Suppl. · Jan 2000
The synergistic effect of acute subdural hematoma combined with diffuse traumatic brain injury on brain edema.
It is well-documented that acute subdural hematoma (ASDH) following diffuse traumatic brain injury (dTBI) contributes to severe disability and high mortality. The objective of this study was to characterize edema formation in a model of ASDH and ASDH following dTBI. Eighteen Sprague-Dawley rats were separated into three groups: Sham operated (n = 6), ASDH (n = 6), ASDH following dTBI (n = 6). ⋯ We conclude that edema formation in ASDH is worsened by the combination of dTBI and ASDH. Furthermore a diffuse and focal injury in combination retain the features of the diffuse injury, but with increased severity. Further studies are required to elucidate the synergistic mechanisms involved in these pathological processes.
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Acta Neurochir. Suppl. · Jan 2000
Effects of hypothermia on intracranial hemodynamics and ischemic brain damage-studies in the rat acute subdural hematoma model.
Brain ischemia is the leading pathophysiological mechanism in the development of secondary brain damage after subdural hematoma (SDH). Hypothermia has been used as the effective neuroprotective treatment in clinical and laboratory studies of ischemic brain injury. In this study, we have examined the rat acute SDH model to assess the effect of hypothermia upon intracranial hemodynamics and also upon ischemic brain injury 4 hours after the induction of hematoma. ⋯ This reduction in brain edema formation was comparable to the result of MK-801 (2 mg/kg) treatment (80.95 +/- 0.35%; p < 0.01). Ischemic brain damage detected by H-E staining was also significantly reduced in the hypothermia and MK-801 treated groups (59.1 +/- 12.3 mm3 and 66.4 +/- 13.8 mm3; p < 0.01 and p < 0.05) compared with the normothermic control group (86.6 +/- 20.7 mm3). In conclusion, the present study demonstrates that hypothermia is a potent neuroprotective method and an inhibition of the glutamate excitotoxic process may contribute the protective mechanisms of hypothermia in this rat acute SDH model.
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Acta Neurochir. Suppl. · Jan 2000
Low extracellular (ECF) glucose affects the neurochemical profile in severe head-injured patients.
Glucose (Gluc) is the main energy source for the brain. After severe head-injury energy demand is massively increased and supply is often decreased. In pilot microdialysis studies, many patients with severe head-injury had undetectable glucose concentrations, probably reflecting changes in metabolism and/or reduced supply. ⋯ There was also no correlation between outcome and the dialysate glucose. The results indicate that low ECF glucose is almost always present in severe head-injury. Moreover, the lack of correlation between low glucose and outcome, however, suggests that other energy substrates, such as lactate, are important after TBI.
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Acta Neurochir. Suppl. · Jan 2000
Comparative StudyClinical experiences with the dual-switch valve in patients with normal pressure hydrocephalus.
In patients with normal pressure hydrocephalus (NPH) we compared the postoperative results reference to the implanted valve type. In 117 patients diagnosed with normal pressure hydrocephalus there was placement of 47 Cordis Standard valves (CSV), 20 Cordis Orbis Sigma valves type I (OSV) and 50 Miethke Dual-switch valves (DSV). Ninety-five patients (36/19/40) were re-evaluated. ⋯ The course of disease in patients with NPH is influenced by the stage of disease--degree of cerebral atrophy--and also by the implanted valve type. The great amount of overdrainage complications and subdural hematomas in the Cordis Orbis Sigma valve group may be an argument against this valve. Our clinical experiences with the Miethke Dual-switch valve show that this hydrostatic valve may be advantageous for patients with NPH.