Articles: brain-injuries.
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Acta Neurochir. Suppl. · Jan 2000
A study of the effects of using different cerebral perfusion pressure (CPP) thresholds to quantify CPP "secondary insults" in children.
Little is known about the incidence of secondary insults, particularly cerebral perfusion pressure insults, in children. The objectives of this study were to assess the duration of CPP insults at three different thresholds in children and to relate CPP insults to outcome. Eighteen children (age < 16, median & mean 8 years) admitted to the Neurointensive Care Unit who had ICP, MAP and CPP continuously monitored were studied. ⋯ However, ICP increased slightly on average from about 13-->17 mmHg when CPP decreased from the < 70 to < 60 mmHg group (p < 0.001). There was a marked increase in ICP to greater than 30 mmHg on average in the CPP < 50 mmHg group (p < 0.001). CPP insults less than 70, 60 and 50 mmHg do occur commonly in children, a larger dataset and possibly longer term follow up measures will be needed to identify potentially treatable physiological factors most effecting the outcome of children.
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After severe craniocerebral trauma a 14-year-old boy developed progressive exophthalmos with venous congestion and chemosis, due to a direct caroticocavernous fistula. Angiography revealed traumatic occlusion of the ipsilateral internal carotid artery and absence of the inferior petrosal sinus. After failure of an approach via the anterior and posterior communicating arteries, the cavernous sinus was successfully catheterised through the occluded internal carotid artery, and embolisation performed with coils.
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Acta Neurochir. Suppl. · Jan 2000
On-line monitoring of substrate delivery and brain metabolism in head injury.
Head injury is associated with complex pathophysiological changes in metabolism. The objective of the study was to investigate these changes by applying on-line bedside monitoring of cerebral metabolism using microdialysis. Following approval by the Local Ethics Committee and consent from the next of kin, a microdialysis catheter was inserted into the frontal cortex of patients with severe head injury. ⋯ Patients in whom the glutamate level remained elevated or in whom secondary rises in glutamate were seen had a poor outcome. The application of bedside analysis of microdialysis enables the progress of the patient to be monitored on-line. In addition to establishing trends of improving and deteriorating metabolism, the technique has the potential to monitor the effects of therapeutic manoeuvres on the biochemistry.
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Acta Neurochir. Suppl. · Jan 2000
Does an increase in cerebral perfusion pressure always mean a better oxygenated brain? A study in head-injured patients.
The adequate management of cerebral perfusion pressure (CPP) continues to be a controversial issue in head-injured patients. The purpose of our study was to test two hypotheses. The first was that in patients with a CPP below 70 mm Hg, oxygen delivery is compromised and that therefore signs of tissue hypoxia would be reflected in low PtiO2 measurements. ⋯ In our study a low PtiO2 was not observed in patients with marginally low CPPs (48-70 mm Hg) and readings below 15 mm Hg were observed in cases with both normal or supranormal CPPs. We conclude that episodes of low PtiO2 could not be predicted on the basis of CPP alone. On the other hand, raising CPP did not increase oxygen availability in the majority of cases, even if the CPP was markedly improved.
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Acute neuropathology following experimental traumatic brain injury results in the rapid necrosis of cortical tissue at the site of injury. This primary injury is exacerbated in the ensuing hours and days via the progression of secondary injury mechanism(s) leading to significant neurological dysfunction. Recent evidence from our laboratory demonstrates that the immunosuppressant cyclosporin A significantly ameliorates cortical damage following traumatic brain injury. ⋯ The findings demonstrate that the neuroprotection afforded by cyclosporin A is dose-dependent and that a therapeutic window exists up to 24h post-injury. Furthermore, the optimal cyclosporin dosage and regimen markedly reduces disruption of the blood-brain barrier acutely following a cortical contusion injury, and similarly affords significant neuroprotection following fluid percussion injury. These findings clearly suggest that the mechanisms responsible for tissue necrosis following traumatic brain injury are amenable to pharmacological intervention.