Articles: brain-injuries.
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We assessed local cerebral glucose metabolism (lCMRGlc) and blood flow (lCBF) interrelationships in the first hour after parasagittal fluid-percussion head injury (FPI) in rats. Matched series were studied autoradiographically for lCMRGlc and lCBF with 2-[14C]deoxyglucose and 14C-labeled iodoantipyrine, respectively. Three-dimensional autoradiographic-image mapping was to generate average data sets from which a mean ICMRGlc-to-lCBF ratio data set was derived. lCBF in neocortical regions ipsilateral to the trauma were depressed, on average, by 44% compared with sham-FPI rats, whereas contralateral lCBF values were not altered. ⋯ The extent of metabolism-flow uncoupling, on average, amounted to 2.5-fold in the ipsilateral hippocampus and neocortex and 1.7-fold contralaterally. The loci of pronounced metabolism-flow dissociation corresponded closely to the previously documented histological distribution of neuronal necrosis. Our findings resemble events occurring in the acute focal ischemic penumbra and suggest that similar injury mechanisms may be operative.
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The modern soldier, as with his predecessors, remains at risk from penetrating cranio-cerebral injury. The subject is briefly reviewed and the modern approach outlined in a military context.
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Intracerebral cytokine production is thought to be partially responsible for the brain edema and increased leukocyte adhesion seen after head injury by both a direct effect on vascular permeability and by causing leukocyte activation. Cerebrospinal fluid concentrations of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and IL-6 are elevated after traumatic brain injury. The cerebral endothelium has not been investigated as a de novo source of cytokines after injury. ⋯ HCME subjected to percussion injury secreted significantly more TNF-alpha at 8 and 24 hours and significantly more IL-1beta at 4 and 24 hours compared with uninjured controls (p < 0.05, Student's t test). These data suggest that HCME production of inflammatory cytokines occurs after traumatic brain injury independent of systemic influences. In situ cytokine production by HCME after percussion trauma may mediate the increased cerebral leukocyte accumulation and cerebrovascular dysfunction observed after focal brain injury.
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Brain injury : [BI] · Jun 1997
Substance abuse, traumatic brain injury and neuropsychological outcome.
The neuropsychological performance of 119 patients with severe closed traumatic brain injury (TBI) who had received toxicology screens at the time of trauma centre admission was examined. Three groups were created: normal screen, positive alcohol screen, or positive abused drugs screen (with or without the presence of alcohol). The admitting Glasgow Coma Scale (GCS) score was significantly lower in the positive alcohol screen group than the normal screen group, while the three groups did not differ in length of post-traumatic amnesia (PTA) or years of education. ⋯ Normal screen patients also scored significantly higher than positive alcohol screen patients on FIQ and VIQ indices and all five indices from the Wechsler Memory Scale-Revised. These data suggest the existence of an additive effect of substance abuse on neuropsychological outcome in TBI. Findings have potential implications for both acute management and rehabilitation of TBI.
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Neurological research · Jun 1997
Influence of body position on tissue-pO2, cerebral perfusion pressure and intracranial pressure in patients with acute brain injury.
It is a common practice to position head-injured patients in bed with the head elevated above the level of the heart in order to reduce intracranial pressure (ICP). This practice has been in vivid discussion since some authors argue a horizontal body position will increase the cerebral perfusion pressure (CPP) and therefore improve cerebral blood flow (CBF). However, ICP is generally significantly higher in the horizontal position. ⋯ However, regional ti-pO2 was unaffected by body position (30 degrees vs. 0 degree: 24.9 + 13.1 vs. 24.7 + 12.9 mmHg). In addition, there was no change in the time course after trauma concerning these findings in the individual patients. The data indicate that a moderate head elevation of 30 degrees reduces ICP without jeopardizing regional cerebral microcirculation as monitored using a polarographic ti-pO2 microcatheter.