Articles: brain-injuries.
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Journal of neurosurgery · Aug 2000
Immediate coma following inertial brain injury dependent on axonal damage in the brainstem.
Immediate and prolonged coma following brain trauma has been shown to result from diffuse axonal injury (DAI). However, the relationship between the distribution of axonal damage and posttraumatic coma has not been examined. In the present study, the authors examine that relationship. ⋯ These results suggest that injury to axons in the brainstem plays a major role in induction of immediate posttraumatic coma and that DAI can occur without coma.
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Intensive care medicine · Aug 2000
Early translaryngeal tracheostomy in patients with severe brain damage.
To describe the effects of early translaryngeal tracheostomy on intracranial pressure (ICP), cerebral perfusion pressure (CPP), and jugular bulb saturation (SjO2); to identify the main mechanisms affecting ICP during tracheostomy; and to evaluate the long-term effects of tracheostomy on tracheal anatomy and function. ⋯ Translaryngeal tracheostomy, performed in selected patients when the risk of intracranial hypertension was reduced to the minimum, was well tolerated in the majority of cases and did not induce persistent intracranial disorders. However, ICP is affected by tracheostomy, and careful monitoring and patient selection is necessary. At follow-up no severe anatomical or functional damage was detected.
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Journal of neurotrauma · Aug 2000
Impaired autoregulation of cerebral blood flow in an experimental model of traumatic brain injury.
In order to study the pathophysiology and the intracranial hemodynamics of traumatic brain injury, we have developed a modified closed-head injury model of impact-acceleration that expresses several features of severe head injury in humans, including acute and long-lasting intracranial hypertension, diffuse axonal injury, neuronal necrosis, bleeding, and edema. In view of the clinical relevance of impaired autoregulation of cerebral blood flow after traumatic brain injury, and aiming at further characterization of the model, we investigated the autoregulation efficiency 24 h after experimental closed-head injury. Cortical blood flow was continuously monitored with a laser-Doppler flowmeter, and the mean arterial blood pressure was progressively decreased by controlled hemorrhage. ⋯ The break point tended towards higher values in the closed head injury group (62.2 +/- 20.8 mm Hg versus 46.9 +/- 12.7 mm Hg; mean +/- SD, p = 0.198). It is concluded that cerebral autoregulation in this modified closed head injury model is impaired 24 h after traumatic brain injury. This finding, in addition to other characteristic features of severe head injury established earlier in this model, significantly contributes to its clinical relevance.
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Traumatic brain injury (TBI) has been shown to induce a significant change in polyamine metabolism. Polyamines and polyamine-dependent calcium influx play an important role in mediating the effects of excitotoxic amino acids at the N-methyl-D-aspartate (NMDA) receptor site. We studied the effects of ifenprodil, known as a noncompetitive inhibitor of polyamine sites at the NMDA receptor, on brain edema formation, blood-brain barrier breakdown, and volume of injury after TBI. ⋯ The polyamine-site NMDA receptor antagonist ifenprodil affords significant neuroprotection in a controlled cortical impact brain injury model and may hold promise for the discovery and treatment of the mechanism of delayed neurological deficits after TBI.
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Pediatric neurosurgery · Aug 2000
Age-related differences in acute physiologic response to focal traumatic brain injury in piglets.
The goal of the present study was to determine whether age-related differences in the acute physiologic response to scaled cortical impact injury contribute to differences in vulnerability to traumatic brain injury (TBI). ⋯ CBF was shown to have a significant age-dependent response to TBI with the youngest animals exhibiting increased CBF following injury.