Journal of neurotrauma
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Journal of neurotrauma · Apr 2007
Impaired percent alpha variability on continuous electroencephalography is associated with thalamic injury and predicts poor long-term outcome after human traumatic brain injury.
Continuous electroencephalography (cEEG) is potentially useful in determining prognosis in patients with traumatic brain injuries (TBI). The objective of this prospective, observational cohort study was to determine if the percent alpha variability (PAV) on cEEG was predictive of outcome following TBI. Injury characteristics were indexed to assess whether lesions in specific cerebral loci were correlated with PAV and patient recovery. ⋯ Inclusion of PAV enhanced the accuracy of prediction models that encompassed a selective combination of clinical and anatomical variables (adjusted R(2) = 0.458, p < 0.001). The two main results of this study are (1) PAV is a sensitive predictor of 6-month clinical outcomes following TBI, and (2) injury to the thalamus is related to impaired PAV. PAV appears best utilized as a functional adjunct to traditional clinical and anatomical predictors.
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Journal of neurotrauma · Apr 2007
NMDA receptor antagonist felbamate reduces behavioral deficits and blood-brain barrier permeability changes after experimental subarachnoid hemorrhage in the rat.
Increased levels of glutamate and aspartate have been detected after subarachnoid hemorrhage (SAH) that correlate with neurological status. The NMDA receptor antagonist felbamate (FBM; 2-phenyl-1,3-propanediol dicarbamate) is an anti-epileptic drug that elicits neuroprotective effects in different experimental models of hypoxia-ischemia. The aim of this dose-response study was to evaluate the effect of FBM after experimental SAH in rats on (1) behavioral deficits (employing a battery of assessment tasks days 1-5 post-injury) and (2) blood-brain barrier (BBB) permeability changes (quantifying microvascular alterations according to the extravasation of protein-bound Evans Blue by a spectrophotofluorimetric technique 2 days post-injury). ⋯ FBM also decreased BBB permeability changes in frontal, temporal, parietal, occipital, and cerebellar cortices; subcortical and cerebellar gray matter; and brainstem. This study demonstrates that, in terms of behavioral and microvascular effects, FBM is beneficial in a dose-dependent manner after experimental SAH in rats. These results reinforce the concept that NMDA excitotoxicity is involved in the cerebral dysfunction that follows SAH.
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Journal of neurotrauma · Apr 2007
Trauma-associated inflammatory response impairs embryonic stem cell survival and integration after implantation into injured rat brain.
Pluripotent embryonic stem cells were shown to survive and differentiate into mature neuronal cells after implantation in experimental models of Parkinson disease and cerebral ischemia. Embryonic stem cell transplantation has also been proposed as a potential therapy for cerebral trauma, characteristic of massive loss of multiple cell types due to primary insult and secondary sequelae. Green fluorescent protein (GFP)-transfected murine embryonic stem cells were implanted into the ipsi or contralateral cortex of male Sprague-Dawley rats 72 h after fluid-percussion injury. ⋯ Cerebral trauma, induced 3 days prior to implantation, has activated the inflammatory potential of otherwise immunologically privileged tissue. Subsequent cell implantation was accompanied by reactive astrogliosis, activation of microglia, as well as a massive invasion of macrophages into transplantation sites even if the grafts were placed into contralateral healthy hemispheres, remote from the traumatic lesion. Our results demonstrate a significant post-traumatic inflammatory response, which impairs survival and integration of implanted stem cells and has generally not been taken into account in designs of previous transplantation studies.