Journal of neurotrauma
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The pulsatile component of intracranial pressure (ICP) has been shown to be a predictor of outcome in normal pressure hydrocephalus (NPH) and traumatic brain injury (TBI). Experimental studies have demonstrated that the pulse amplitude of ICP (AMP(ICP)) is dependent on the mean ICP (mICP), and on the pulse amplitude of the cerebral arterial blood volume (AMP(CaBV)), according to the exponential craniospinal compliance curve. In this study, we compared the influence of mICP and AMP(CaBV) on AMP(ICP) in patients with NPH (infusion study) and TBI (spontaneous recording). ⋯ On the contrary, AMP(ICP) was more dependent on AMP(CaBV) in patients with TBI than in those with NPH (b = 0.86 versus 0.10; p < 0.001). This study shows that AMP(ICP) depends mostly on changes in mean ICP during cerebrospinal fluid (CSF) infusion studies in patients with NPH, and on changes in cerebral arterial blood volume (AMP(CaBV)) in TBI patients. Further clinical studies will reveal whether AMP(ICP) is a better indicator of clinical severity and outcome than mICP in TBI and NPH patients.
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Journal of neurotrauma · Feb 2010
Adrenomedullin prevents sex-dependent impairment of autoregulation during hypotension after piglet brain injury through inhibition of ERK MAPK upregulation.
Cerebrospinal fluid (CSF) adrenomedullin (ADM) levels are increased in female, but remain unchanged in male, piglets after fluid percussion injury (FPI) of the brain. Subthreshold vascular concentrations of ADM restore impaired hypotensive pial artery dilation after FPI more in males than females. Extracellular signal-related kinase (ERK) mitogen-activated protein kinase (MAPK) is upregulated and contributes to reductions in cerebral blood flow (CBF) after FPI. ⋯ The calculated autoregulatory index was unchanged during hypotension in sham animals, but was reduced more in males than females during hypotension and FPI. ADM prevented reductions in autoregulation during hypotension and FPI more in males than females. These data indicate that ADM prevented loss of cerebral autoregulation after FPI in a sex-dependent and ERK MAPK-dependent manner.
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Journal of neurotrauma · Feb 2010
Acute and chronic deficits in the urinary bladder after spinal contusion injury in the adult rat.
Traumatic spinal cord injury (SCI) permanently alters bladder function in humans. Hematuria and cystitis occur in both human SCI as well as in rodent models of SCI. Others have reported early SCI-dependent disruption to bladder uroepithelial integrity that results in increased permeability to urine and urine-borne substances. ⋯ An SCI-dependent elevation in numbers of neutrophils within the bladder wall peaked at 48 h. Bladder tight junction proteins demonstrate a rapid but transient decrease as early as 2 h post-SCI. Surprisingly, elevated levels of urine proteins and significant deficits in bladder tight junction proteins could be detected in chronic SCI, suggesting that early pathological changes to the bladder may continue throughout the chronic phase of injury.
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Journal of neurotrauma · Feb 2010
Transcriptomics of traumatic brain injury: gene expression and molecular pathways of different grades of insult in a rat organotypic hippocampal culture model.
Traumatic brain injury (TBI) is the one of the most common forms of head trauma, and it remains a leading cause of death and disability. It is known that the initial mechanical axonal injury triggers a complex cascade of neuroinflammatory and metabolic events, the understanding of which is essential for clinical, translational, and pharmacological research. These can occur even in mild TBI, and are associated with several post-concussion manifestations, including transiently heightened vulnerability to a second insult. ⋯ The data revealed remarkable differential gene expression following mTBI, even in the absence of cell damage. Pathway analysis revealed that molecular interactions in both levels of injury were similar, with IL-1beta playing a central role. Additional pathways of neurodegeneration involving RhoA (ras homolog gene family, member A) were found in 50% stretch.