Articles: brain-injuries.
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Journal of neurotrauma · Oct 1994
Modification of the cortical impact model to produce axonal injury in the rat cerebral cortex.
Diffuse axonal injury (DAI) is a form of brain injury that is characterized by morphologic changes to axons throughout the brain and brainstem. Previous biomechanical studies have shown that primary axonal dysfunction, ranging from minor electrophysiologic disturbances to immediate axotomy, can be related to the rate and level of axonal deformation. Some existing rodent head injury models display varying degrees of axonal injury in the forebrain and brainstem, but the extent of axonal damage in the forebrain has been limited to the contused hemisphere. ⋯ Neurofilament immunohistochemistry revealed numerous axonal retraction balls in the subcortical white matter and overlying deep cortical layers in the right hemisphere beneath the contralateral craniotomy. Retraction balls were not seen at these positions in normals, sham controls, or animals that received cortical impact without contralateral craniotomy and dural opening. The results from these physical modeling and animal experiments indicate that opening of the contralateral dura mater permits translation of sufficient mechanical deformation across the midline to produce a more widespread pattern of axonal injury in the forebrain, a pattern that is distinct from those produced by existing fluid percussion and cortical impact techniques.
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Neurosurg. Clin. N. Am. · Oct 1994
ReviewIntegrated multimodality monitoring in the neurosurgical intensive care unit.
The selection of variables for continuous monitoring in the neurosurgical intensive care unit is based upon the requirement for constant perfusion and oxygenation of the brain and knowledge of the frequency and prognostic significance of abnormal values. Both arterial and intracranial pressure must be considered in the form of cerebral perfusion pressure. Body temperature and arterial oxygen saturation are essential to monitoring. Measurement of jugular venous oxygen saturation and cerebral blood flow velocity provide information of value in determining the source of raised intracranial pressure, the most appropriate means of treating it, and the safety of therapy.
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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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Brain injury : [BI] · Oct 1994
Family functioning, social support and depression after traumatic brain injury.
Functional outcome after traumatic brain injury (TBI) is thought to be dependent upon effective social support and avoidance of depressive episodes. Research indicates that post-injury changes often occur in the family's functioning, hence impacting the family's ability to provide the needed social support. Social support, in turn, has been hypothesized to work as a buffer between significant life event and levels of depressive symptoms. ⋯ Thirty-nine persons who had sustained TBI were interviewed to assess their family functioning, perceived social support, and current depressive symptomatology. The results showed that the effective use of problem-solving and behavioural coping strategies by the family in response to TBI was significantly related to lower levels of depression in the person who sustained the TBI. However, perceived social support was not predictive of depression.