Journal of neurotrauma
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Journal of neurotrauma · Jan 2011
Case ReportsDecompressive craniectomy for severe head injury: does an outcome prediction model influence clinical decision-making?
The use of a prognostic model to aid clinician decision-making with regard to decompressive craniectomy for patients with severe neurotrauma has not been examined. Thus in this study we assessed whether an internationally validated prediction model would influence clinician decision-making about craniectomy. A two-part structured interview, given before and after knowing the predicted risks of unfavorable neurological outcomes at 6 months, was used to assess the participants' recommendations about performing decompressive craniectomy in three patients with severe traumatic brain injury. ⋯ The participants were significantly more likely to recommend decompressive craniectomy for their patients than for themselves, especially when the next of kin of the patient demanded the procedure, and were more similar in their own preferences to patients who had advance directives. Clinicians' preferences to perform the procedure for both themselves and their patients was significantly reduced after knowing the predicted risks of unfavorable outcomes, and these changes in attitude were consistent across those with different specialties, regardless of the amount of experience caring for similar patients, or religious background. In conclusion, the predicted risks of unfavorable outcomes influenced clinician decision-making about recommending decompressive craniectomy for patients with very severe neurotrauma.
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Journal of neurotrauma · Jan 2011
Post-traumatic seizures exacerbate histopathological damage after fluid-percussion brain injury.
The purpose of this study was to investigate the effects of an induced period of post-traumatic epilepsy (PTE) on the histopathological damage caused by traumatic brain injury (TBI). Male Sprague Dawley rats were given a moderate parasagittal fluid-percussion brain injury (1.9-2.1 atm) or sham surgery. At 2 weeks after surgery, seizures were induced by administration of a GABA(A) receptor antagonist, pentylenetetrazole (PTZ, 30 mg/kg). ⋯ In addition, the TBI-PTZ rats showed less NeuN-immunoreactive cells within the ipsilateral parietal cerebral cortex (p < 0.05) and there was a trend for decreased hippocampal CA3 neurons in TBI-PTZ rats compared with TBI-saline or sham-operated rats. These results demonstrate that an induced period of post-traumatic seizures significantly exacerbates the structural damage caused by TBI. These findings emphasize the need to control seizures after TBI to limit even further damage to the injured brain.
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Journal of neurotrauma · Jan 2011
Antinociceptive effect of riluzole in rats with neuropathic spinal cord injury pain.
Symptoms of neuropathic spinal cord injury (SCI) pain include cutaneous hypersensitivity and spontaneous pain below the level of the injury. Riluzole, an FDA-approved drug for the treatment of amyotrophic lateral sclerosis, has been demonstrated to attenuate neural excitotoxicity by blocking the effects of the excitatory amino acid glutamate on glutamate receptors and by inhibiting voltage-gated Na(+) and Ca(2+) channels. Neuropathic pain in rat models of SCI is thought to be mediated by dysfunctional ion channels and glutamate receptors expressed on CNS neurons. ⋯ Although riluzole appears to have a general antinociceptive effect, the site of action may be model dependent. In total, these data indicate that riluzole may be an effective clinical analgesic for the treatment of below-level neuropathic SCI pain. Although the exact mechanism of action is not clear, there is a predominant supraspinal component of riluzole-induced antinociception in SCI rats.
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Traumatic brain injuries (TBI) caused by improvised explosive devices (IEDs) affect a significant percentage of surviving soldiers wounded in Iraq and Afghanistan. The extent of a blast TBI, especially initially, is difficult to diagnose, as internal injuries are frequently unrecognized and therefore underestimated, yet problems develop over time. Therefore it is paramount to resolve the physical mechanisms by which critical stresses are inflicted on brain tissue from blast wave encounters with the head. ⋯ Our results demonstrate that proper sealing techniques lead to a significant increase in ICP values, compared to the outside overpressure generated by the blast. Further, the values seem to have a direct relation to a rat's size and age: heavier, older rats had the highest ICP readings. These findings suggest that a global flexure of the skull by the transient shockwave is an important mechanism of pressure transmission inside the brain.
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Journal of neurotrauma · Jan 2011
Electrocortical pathology in a rat model of penetrating ballistic-like brain injury.
Traumatic brain injury (TBI) causes severe disruption of cerebral electrical activity and electroencephalography (EEG) is emerging as a standard tool to monitor TBI patients in the acute period of risk for secondary injuries. However, animal studies of EEG pathology in the context of TBI are surprisingly sparse, largely because of the lack of real-time continuous EEG (cEEG) monitoring in animal TBI models. Here, we performed long-term EEG monitoring to study nonconvulsive seizures (NCS), periodic epileptiform discharges (PED), and EEG power spectra following three injury severity levels in a rat model of penetrating ballistic-like brain injury (PBBI). ⋯ In contrast, decreases in higher frequency power (i.e., 30-35 Hz) remained depressed throughout 14 days. This is the first long-term cEEG study of the acute injury phase in a rat model of severe TBI, demonstrating common occurrences of clinically observed electrocortical pathology, such as NCS, PED, and cortical slowing. These EEG pathologies may serve as critical care biomarkers of brain injury, and offer clinically relevant metrics for studying acute therapeutic interventions.