Acta neurochirurgica. Supplement
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Acta Neurochir. Suppl. · Jan 2006
Controlled Clinical TrialTraumatic brain edema in diffuse and focal injury: cellular or vasogenic?
The objective of this study was to confirm the nature of the edema, cellular or vasogenic, in traumatic brain injury in head-injured patients using magnetic resonance imaging techniques. Diffusion-weighted imaging methods were quantified by calculating the apparent diffusion coefficients (ADC). Brain water and cerebral blood flow (CBF) were also measured using magnetic resonance and stable Xenon CT techniques. ⋯ In contrast, in patients with significant brain swelling ADC values were reduced and averaged 0.74 +/- 0.05 (p < 0.0001), consistent with a predominantly cellular edema. We also found that the CBF in these regions was well above ischemic threshold at time of study. Taking these findings in concert, it is concluded that the predominant form of edema responsible for brain swelling and raised ICP is cellular in nature.
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Acta Neurochir. Suppl. · Jan 2006
Detection of boundaries of subthalamic nucleus by multiple-cell spike density analysis in deep brain stimulation for Parkinson's disease.
When microelectrode recording of single cell activity is employed for targeting the subthalamic nucleus (STN), multiple sampling of single cells is needed to determine whether the electrode has passed through the ventral boundaries of the STN. In contrast, stepwise recording of multiple cell activities by a semimicroelectrode reveals robust changes in such activities at the dorsal and ventral boundaries. We attempted to quantify changes in multiple cell activities by computing multiple-cell spike density (MSD). ⋯ Both the dorsal and ventral boundaries were clearly identified by an increase and a decrease (p < 0.0001) in MSD, respectively, in all the 60 sides. The cut-off level of 1.2-fold showed the clearest change in MSD between the STN and the pars reticulata of substantia nigra. MSD analysis by semimicroelectrode recording represents the most practical means of identifying the boundaries of STN.
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Acta Neurochir. Suppl. · Jan 2006
Controlled Clinical TrialChanges in coagulative and fibrinolytic activities in patients with intracranial hemorrhage.
To investigate whether any changes occur in the coagulative/fibrinolytic cascade in patients with subarachnoid hemorrhage (SAH) or hypertensive intracerebral hemorrhage (HICH). ⋯ Both coagulative and fibrinolytic activities were altered after the onset of SAH. These results demonstrate that the coagulative/fibrinolytic cascade might be activated via different mechanisms in different types of stroke. It remains unclear, however, whether a significant alteration of the fibrinolytic cascade in patients with ROSC-SAH might be a nonspecific phenomenon attributable to the reperfusion after collapse.
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Acta Neurochir. Suppl. · Jan 2006
Protective effect of the V1a receptor antagonist SR49059 on brain edema formation following middle cerebral artery occlusion in the rat.
There exists no pharmacological treatment for fulminating brain edema. Since evidence indicates that brain aquaporin-4 (AQP4) water channels are modulated by vasopressin V1a receptors, we examined the edema-reducing properties of the selective V1a receptor antagonist, SR49059, following middle cerebral artery occlusion (MCAO). Male Sprague-Dawley rats were randomly assigned to sham procedure, vehicle, or SR49059 infusion at different dosages (each n = 6,480 microL/hr, 640 microL/hr, 720 microL/hr) and starting 60 minutes before or after MCAO. ⋯ The consecutive sodium shift into the brain was prevented (p = 0.001), while the potassium loss was inhibited only by pre-treatment (p = 0.003). These findings imply that in ischemia-induced brain edema, the selective V1a receptor-antagonist SR49059 inhibits brain edema and the subsequent sodium shift into brain. This substance offers a new avenue in brain edema treatment and prompts further study into AQP4 modulation.
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Acta Neurochir. Suppl. · Jan 2006
Case ReportsPositive selective brain cooling method: a novel, simple, and selective nasopharyngeal brain cooling method.
Brain damage is worsened by hyperthermia and prevented by hypothermia. Conventional hypothermia is a non-selective brain cooling method that employs cooling blankets to achieve surface cooling. This complicated method sometimes induces unfavorable systemic complications. ⋯ The chilled air was exhaled through the oral cavity. In most patients, PSBC maintained normal brain temperature. This new technique provides quick induction of brain temperature control and does not require special facilities.