Search results for "Cerebral edema"

Kinetics of Photofrin II in perifocal brain edema.

1993

Photodynamic therapy is under intense investigation as a possible adjuvant for the treatment of malignant tumors of the central nervous system. It relies on the fact that photosensitizers are selectively taken up or retained by malignant tissue. However, most brain tumors are accompanied by substantial vasogenic edema as a consequence of blood-brain barrier disruption within the tumor, leading to extravasation and propagation of plasma constituents into the surrounding brain tissue. Systemically administered photosensitizers may enter healthy tissue together with the edema fluid, possibly leading to sensitization of tissues outside the tumor. To test this hypothesis, vasogenic edema was ind…

Inhibition of the myosin light chain kinase prevents hypoxia-induced blood-brain barrier disruption

2007

Increased mortality after stroke is associated with development of brain edema. The aim of the present study was to examine the contribution of endothelial myosin light chain (MLC) phosphorylation to hypoxia-induced blood-brain barrier (BBB) opening. Measurements of trans-endothelial electrical resistance (TEER) were performed to analyse BBB integrity in an in vitro co-culture model (bovine brain microvascular endothelial cells (BEC) and rat astrocytes). Brain fluid content was analysed in rats after stroke induction using a two-vein occlusion model. Dihydroethidium was used to monitor intracellular generation of reactive oxygen species (ROS) in BEC. MLC phosphorylation was detected using i…

2002

Summary Background. Photodynamic therapy (PDT) has been under dis- cussion as additional treatment option for malignant gliomas. How- ever, damage not only to tumour tissue but also to normal brain has been demonstrated. The mechanisms of this unwanted side eect have not yet been clearly identified. Spreading of photosensitiser with oedema after disruption of the blood-brain-barrier and poten- tial sensitisation of normal tissue has been foundpreviously. The present study investigates the time- and dose-dependency of normal tissue damage to photodynamic therapy using Photofrin II9 after disruption of the blood-brain-barrier. Methods. Male wistar rats anaesthetisedwith chloral hydrate were s…

Clearance of Edema Fluid into Cerebrospinal Fluid

1983

The formation of cerebral edema appears to be the response of the brain to injury from a diversity of causes, in association with tumors, trauma, and infections, as well as toxic, anoxic, and metabolic disorders. The classification by Klatzo14 of cerebral edema into two major categories, vasogenic edema and cytotoxic edema, has clarified our understanding of this pathological problem. A third category has been termed interstitial 10 or hydrocephalic 17 edema. The various processes are not mutually exclusive. In ischemic brain edema, changes characteristic of vasogenic and cytotoxic cerebral edema occur, and in subarachnoid hemorrhage, all three types of edematous changes may develop. Nevert…

Possible Role of Glymphatic System of the Brain in the Pathogenesis of High-Altitude Cerebral Edema

2018

Simka, Marian, Paweł Latacz, and Joanna Czaja. Possible role of glymphatic system of the brain in the pathogenesis of high-altitude cerebral edema. High Alt Med Biol. 19:394–397, 2018.—In this article, we suggest that the glymphatic system of the brain can play an important role in the pathogenesis of high-altitude cerebral edema (HACE). Water enters the intercellular space of the brain primarily through aquaporin-4 (AQP-4) water channels, the main component of the glymphatic system, whereas acetazolamide, pharmacological agent used in the prevention of HACE, is the blocker of the AQP-4 molecule. In animal experiments, cerebral edema caused by hypobaric hypoxia was associated with an increa…

Pathophysiology of Cerebral Ischemia

1991

The weight of the brain amounts to only 2% of total body weight, but it receives 15% of the cardiac output and uses 20% of the oxygen consumed by the body. The energy supply is provided almost exclusively by glucose metabolism. The substrate for this is stored in the brain in the form of glucose or glycogen and is sufficient to cover the energy requirements for only about 1 min. Consequently, there is a delicate equilibrium between oxygen and nutrient supply from the blood and the energy requirements of the brain. Disturbances in neurologic function appear after a few seconds of ischemia, although they are not necessarily persistent at first.

Physiopathological, Epidemiological, Clinical and Therapeutic Aspects of Exercise-Associated Hyponatremia.

2014

Exercise-associated hyponatremia (EAH) is dilutional hyponatremia, a variant of inappropriate antidiuretic hormone secretion (SIADH), characterized by a plasma concentration of sodium lower than 135 mEq/L. The prevalence of EAH is common in endurance (<6 hours) and ultra-endurance events (>6 hours in duration), in which both athletes and medical providers need to be aware of risk factors, symptom presentation, and management. The development of EAH is a combination of excessive water intake, inadequate suppression of the secretion of the antidiuretic hormone (ADH) (due to non osmotic stimuli), long race duration, and very high or very low ambient temperatures. Additional risk factors …

The Effect of Dexamethasone on Water and Electrolyte Content and on rCBF in Perifocal Brain Edema in Man

1972

The results of clinical studies are reported dealing with the relationship between cerebral edema and regional cerebral blood flow in patients with brain tumor as well as with the effect of dexamethasone on this relationship. rCBF is found to be significantly reduced in brain tissue surrounding brain tumors. Autoregulation as well as cerebrovascular reactivity to PaCO2 is focally or generally impaired. Water content of perifocal white matter is markedly increased. The combination of tissue lactacidosis, low regional blood flow and vasoparalysis seems to be a characteristic finding in this type of local brain edema. The increased local tissue pressure, due to the increased tissue water conte…