Articles: brain-injuries.
-
Effective management of brain-injured patients requires that nurses have a specialized body of knowledge relating to the pathophysiology and treatment of traumatic brain injury (TBI). Current research in this area has focused on the cascade of secondary injury which leads to the irreversible tissue damage following TBI. Such processes involve excitatory amino acids, neurotransmitters, ion changes, lipid peroxidation, oxygen free radicals, opioids, lactic acidosis and magnesium to name but a few. Given that no accepted treatment paradigm exists to attenuate these secondary processes, nurses may have to autonomously devise individual care plans based on their current understanding of brain injury pathophysiology.
-
Journal of neurotrauma · Apr 1999
Effect of traumatic brain injury in mice deficient in intercellular adhesion molecule-1: assessment of histopathologic and functional outcome.
Intercellular adhesion molecule-1 (ICAM-1) is an adhesion molecule of the immunoglobulin family expressed on endothelial cells that is upregulated in brain as part of the acute inflammatory response to traumatic brain injury (TBI). ICAM-1 mediates neurologic injury in experimental meningitis and stroke; however, its role in the pathogenesis of TBI is unknown. We hypothesized that mutant mice deficient in ICAM-1 (-/-) would have decreased neutrophil accumulation, diminished histologic injury, and improved functional neurologic outcome versus ICAM-1 +/+ wild type control mice after TBI. ⋯ Robust expression of ICAM-1 was readily detected in choroid plexus and cerebral endothelium at 24 h in ICAM-1 +/+ mice but not in ICAM-1 -/- mice. No differences between groups were observed in brain neutrophil accumulation (9.4 +/- 2.2 versus 11.1 +/- 3.0 per x100 field, -/- versus +/+), wire grip score, MWM latency, or lesion volume (7.24 +/- 0.63 versus 7.21 +/- 0.45 mm3, -/- versus +/+). These studies fail to support a role for ICAM-1 in the pathogenesis of TBI.
-
Journal of neurotrauma · Apr 1999
Freeze-fracture and cytochemical evidence for structural and functional alteration in the axolemma and myelin sheath of adult guinea pig optic nerve fibers after stretch injury.
Recent work in animal models of human diffuse axonal injury has generated the hypothesis that, rather than there being physical disruption of the axolemma at the time of injury, a pertubation of the membrane occurs, which leads, over time, to a dysfunction of the physiology of the axolemmal. This dysfunction is posited to lead to a disruption of ionic homeostasis within the injured axon, leading to secondary axotomy some hours after the initial insult. We decided to test the hypothesis that membrane pump/ion channel activity or function is compromised and this would be reflected in structural changes within the axolemma and myelin sheath. ⋯ There was loss of ecto-Ca-ATPase activity but increased labeling for p-NPPase activity at sites of dissociation of compacted myelin. Quantitative freeze-fracture demonstrated statistically significant changes in membrane structure. We provide support for the hypothesis that structural and functional changes occur in the axolemma and myelin sheath at nondisruptive axonal injury.
-
Journal of neurotrauma · Mar 1999
Clinical TrialEffect of moderate hypothermia on systemic and internal jugular plasma IL-6 levels after traumatic brain injury in humans.
Moderate hypothermia may reduce subsequent neuronal damage after traumatic brain injury. Interleukin (IL)-6 may have a role in the pathogenesis of traumatic neuronal damage or repair. Using the enzyme-linked immunological sorbent assay (ELISA), we serially measured IL-6 levels in plasma obtained from the radial artery (systemic) and internal jugular vein (regional) in 13 cerebral trauma patients who underwent hypothermia of 32-33 degrees C ranged from 4-9 days postinjury and 10 head-injured patients who were maintained at normothermic levels (36-37 degrees C). ⋯ The cytokine suppression found in the hypothermic group continued even after rewarming in these patients showing an improved clinical course, but not in those whose condition worsened. In addition to these changes in cytokine levels, the Glasgow Outcome Scale at 6 months postinjury was significantly higher in the hypothermic group than in the normothermia group. Based on the above, this clinical study with its small patient sample size suggests the need for further prospective randomized studies to examine the role of cytokine suppression in the beneficial effects of moderate hypothermia in patients with traumatic brain injury.