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Query: UMLS:C0085584 (encephalopathy)
 18,178 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thirty newborn pigs within 3 days of life were randomly divided into different groups according to the time of hypoxic-ischemic encephalopathy. The results showed that the brain damage and pathologic changes were most obvious in the 60 min hypoxia-ischemic group. Brain edema was observed in every group, especially in the group where hypoxia-ischemic lasted for more than 30 min. Cerebromalacia and hemorrhage in ventricles of brain and in arachnoid were observed, and these were particularly noticed in the group where hypoxia-ischemia lasted for 60 min.
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PMID:[Observation on the animal model of hypoxic-ischemic encephalopathy and the change of pathology in newborn pigs]. 858 4

It has been proposed that alterations of excitatory and inhibitory amino acids play a role in the pathogenesis of hepatic encephalopathy in acute liver failure. To evaluate this possibility, in vivo cerebral microdialysis was used to sample extracellular concentrations of amino acids in the frontal cortex of unanesthetized rats at various times during the progression of encephalopathy resulting from acute liver failure. Liver failure was induced by portacaval anastomosis followed 24 hours later by hepatic artery ligation. Dialysate concentrations of amino acids were measured by high-performance liquid chromatography (HPLC) with fluorescence detection. Deterioration of neurological status was accompanied by two- to four-fold increases in extracellular glutamate, glutamine, and glycine; concentrations of gamma-aminobutyric acid (GABA) and taurine were unchanged. Densities of binding sites for the glutamate (N-methyl-D-aspartate [NMDA]) receptor ligand 3H-MK801, assessed using quantitative receptor autoradiography, however, were unchanged in the frontal cortex of rats at coma stages of ischemic liver failure. Increased extracellular glutamate concentrations were positively correlated with the severity of encephalopathy and with arterial ammonia concentrations. Such changes may result from an ammonia-induced reduction in the capacity for astrocytes to uptake glutamate. Increased extracellular glutamate in brain, together with increases in concentrations of glycine, a positive allosteric modulator of glutamate (NMDA) receptors, are consistent with increased NMDA-related glutamatergic neurotransmission in this model of acute liver failure. Increased extracellular glutamate, therefore, could contribute to the pathogenesis of hepatic encephalopathy and brain edema in acute liver failure.
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PMID:Neuroactive amino acids and glutamate (NMDA) receptors in frontal cortex of rats with experimental acute liver failure. 885 96

Patients with hyponatremia are exposed to major neurological complications. On the one hand hyponatremia itself produces brain edema, increased intracranial pressure which potentially leads to subsequent neuropathological sequelae or death. On the other hand excessive correction could be followed by development of brain demyelinating lesions (central pontine or extrapontine myelinolysis) with major disability or fatal outcome. Understanding of brain adaptative mechanisms to changes in osmolality largely contributes to explain these neurological events. When serum sodium decreases, the brain prevents swelling by extruding electrolytes and organic osmolytes, a process almost fully achieved after 48 h. Conversely, during subsequent increase in serum sodium, reestablishment of intracerebral osmolytes occurs but their reuptake is more delayed (+/- 5 days). In both circumstances, these mechanisms can be overwhelmed, leading to brain damage. Acute hyponatremia (< 48 h) is generally hospital-acquired, mainly in the postoperative state and/or after excessive fluid administration. After abrupt fall in serum sodium, seizure, respiratory arrest and coma may develop and these manifestations are sometimes explosive in nature. Recognition of even minor symptoms is crucial and implies prompt correction. There is generally no risk of brain myelinolysis in acute hyponatremia. Some factors are suspected to aggravate the prognosis of hyponatremic encephalopathy, including female gender (menstruant women), hypoxia and young age. Chronic hyponatremia (> 48 h) usually develops outside the hospital and is generally better tolerated. The risks of brain myelinolysis can be largely reduced by limiting the correction level to < or = 15 mEq/1/24 h. However, if necessary, the initial rate of correction can be rapid provided that the final correction remains < 15 mEq/1/24 h. However, when other recognized risk factors for myelinolysis (hypokalemia, liver disease, poor nutritional state, burns) are present, correction should not exceed 10 mEq/1/24 h. Demyelinization is also observed in hypernatremia but it follows greater (50%) increase in serum sodium than from hyponatremic baseline. For symptomatic hyponatremia, rapid correction is usually obtained by hypertonic saline (3%) infusion. Another option consists in administration of intravenous or oral urea. Urea allows a rapid reduction of brain edema and intracranial pressure which is followed by subsequent correction of hyponatremia. Experimental data also suggest that treatment of hyponatremia with urea is associated with a lower incidence of myelinolysis. In hyponatremic patients without symptoms, there is no need for rapid correction and the treatment should be more conservative. Close monitoring of the serum sodium is indicated initially and if necessary, correction must be stopped and diuresis interrupted with dDAVP. Given recent experimental data, in patients overly corrected (delta SNa > 15 mEq/1/24 h), the risk of myelinolysis could be greatly reduced by rapidly decreasing the serum sodium through hypotonic fluids administration and dDAVP.
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PMID:Therapeutic recommendations for management of severe hyponatremia: current concepts on pathogenesis and prevention of neurologic complications. 887 50

The pathophysiological processes of the nervous system observed in the reactions to aggressive external stresses like severe trauma, systemic infection and so on have been reviewed. As is generally understood, such stresses as tissue destruction lead to the metabolic changes via proprioceptive impulses to central nervous system and neuroendocrinological courses. Cytokines are well known to work to induce systemic inflammatory responses and also to be important components of sepsis syndrome, for example. In the early phase of septic encephalopathy without overt infection of the brain or the meninges, it is possible that cytokines cause capillary leakage with brain edema, interference with microcirculation and direct effects on tissue metabolism resulting in brain dysfunction. And besides, Interleukins are prove to be produced in a few hours post-injury in experimental model. In clinical settings, severe head injury patients, who are often complicated with respiratory or urinary infection and with bacterial translocation, can suffer not only from systemic inflammatory responses originated from the brain but also from septic encephalopathy mentioned above. Therefore multiply traumatized patients with damaged brain for instance might well have to be considered as the aggregation, or integration of the systemic insult from the aspect of aggressology.
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PMID:[The significance of neurological manifestations from the aspect of aggressology]. 894 Jun 84

We present a case of acute lethal poisoning by oil of "epazote" (oil of chenopodium), in a 2 y 9 m female. The volatile oil was administered according to the advice of a "curandera" (female healer), in a total quantity of 40 ml. Clinical features of the poisoning were: vomiting, deep coma, seizures, mydriasis, apnea, metabolic acidosis, neurogenic shock and death. The EEG suggested a diffuse encephalopathy, the CT scan with an image of severe brain edema and ventricular collapse. Relevant postmortem findings were brain edema and neuronal necrosis, pneumonia, enteritis, pericholangitis, mild pancreatitis and tubular necrosis. The phytochemical analysis of volatile oil identified ascaridol, the main active compound of the chenopodium herbs, in a quantity of 39 mg/ml (1,560 mg in the dose administered), and Chenopodium graveolens as the plant employed to prepare it. According to the age of the patient, 60 mg of ascaridol would be the recommended dose formerly used in the treatment of parasitic disease. Thus 1,560 mg was 26 times higher than the recommended dose, and exceeded by 56% the dose of 1,000 mg reported as lethal in humans.
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PMID:[Fatal poisoning caused by oil of epazote, Chenopodium graveolens]. 896 84

A 16 year old patient with the typical clinical signs of Albright's hereditary dystrophia developed series of epileptic seizures with loss of consciousness, tonic muscle contractions and bite of the tongue. After termination of the seizures there was coma without focal neurological signs. CT scan revealed diffuse brain edema. Electroencephalographic studies showed generalized slowing. In laboratory tests the only abnormalities were marked hypocalcemia (1.15 mmol/l) and hyperphosphatemia. Blood parathyroid hormone (PTH) was elevated. PTH-Test confirmed the diagnosis of pseudohypoparathyroidism. The patient was treated with calcium and 1,25-dihydroxy-cholecalciferol. After few days the severe encephalopathy, CT and electroencephalographic changes were completely reversible. Hereditary disturbances of the parathyroid hormone metabolism are rare diseases. Hypocalcemia must be included into the differential diagnosis of seizures and brain edema to avoid invasive diagnostic and irrational treatment.
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PMID:[Acute reversible encephalopathy with brain edema and serial seizures in pseudohypoparathyroidism]. 903 61

With the wide acceptance of liver transplantation as a therapeutic alternative in fulminant hepatic failure (FHF), the successful management of patients with this syndrome has acquired a new urgency. Topping the list of medical problems is the development of brain swelling. Two decades after the recognition of its importance, brain edema and intracranial hypertension still constitute a major cause of death in these patients. In a more recent classification of FHF, brain edema was especially prominent in those subjects with "hyperacute failure," in whom a period of 7 days or less elapsed between the development of jaundice and encephalopathy. The goal of this review is to discuss two aspects of this clinical problem. On one hand, elucidation of its pathogenesis should lead to a more rational therapeutic approach; such an information would also be valuable to understand the relationship between hepatic encephalopathy and brain edema, a source of controversy. Studies of pathogenic mechanisms are difficult to perform in humans and animal models of FHF have proven valuable, as brain swelling can be detected with some regularity. On the other hand, an increasing array of techniques is now available in the intensive care setting to monitor patients with FHF. Of these, intracranial pressure monitoring has received the most critical attention. However, concerns with the risks of craniotomy and the need to acquire more dynamic information has led several groups to explore non-invasive methods that evaluate the consequences of intracranial hypertension. Their role, though potentially exciting, is still uncertain.
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PMID:Cerebral edema and intracranial pressure monitoring. 934 64

An animal model of hypoxic-ischemic encephalopathy (HIE) in newborn pigs was set up to study the histopathological changes of brain injury by light- and electron-microscopy, the changes in total calcium content and calcium iron of RBC, and the effects of two different doses of Nimodipine on HIE. Sixty-one newborn pigs were randomly divided into seven groups, the normal control group (n = 9); the HIE 1-hour group (n = 8) and 24-hour group (n = 8); HIE+ Nimodipine (1 microgram/kg.min-1) 1-hour group (n = 8) and 24-hour group (n = 8). The results showed that these were apparent brain edema, hematencephalon, neuron necrosis, and intracellular body degeneration in the HIE 1-hour group. The levels of RBC TCa and RBC Cai2+ in the HIE 1-hour group were significantly higher than those in the normal control group (P < 0.01). The brain tissues in all groups treated with Nimodipine showed histopathological betterment Compared with the HIE groups. The levels of RBC TCa and RBC Cai2+ in the Nimodipine treatment groups were significantly lower than those in HIE groups (P < 0.01) and were close to the levels in the normal control group (P < 0.05). The authors suggested that early application of Nimodipine in case of postnatal asphyxia might protect the newborn from severe hypoxicischemic brain lesions.
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PMID:[The treated effects of nimodipine on calcium of erythrocyte in experimental hypoxic-ischemic encephalopathy]. 938 66

These is increasing evidence to suggest that central noradrenergic mechanisms may contribute to the central nervous system manifestations of acute liver failure. To further elucidate this possibility, extracellular brain concentrations of the monoamines, noradrenaline (NA), dopamine (DA), and serotonin, were measured by high-performance liquid chromatography with electrochemical detection in microdialysates from the extracellular compartment of frontal cortex in rats with acute (ischemic) liver failure at various times during the progression of encephalopathy and brain edema, as well as in obligate control groups of animals. In addition, binding sites for the noradrenergic receptor subtype ligands, [3H]-prazosin (alpha1 sites), [3H]-RX821002 (alpha2 sites), and [125]I-iodopindolol (beta sites), were assessed using quantitative receptor autoradiography in regions of the brains of rats at coma stage of acute liver failure and of control groups of animals. Coma stages of encephalopathy in acute liver failure were associated with selectively increased noradrenaline concentrations (P < .05) and a concomitant selective loss of alpha1 and beta1 sites in frontal cortex and thalamus. These findings add to a growing body of evidence that central noradrenergic function is modified in acute liver failure and suggest that alpha1/beta1 receptor-mediated noradrenergic mechanisms may play a role in the pathogenesis of brain edema and encephalopathy in this condition.
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PMID:Evidence for altered central noradrenergic function in experimental acute liver failure in the rat. 946 32

Pancreatic encephalopathy is a severe complication of acute pancreatitis. Proinflammatory cytokines may play a role in the development of multi-organ failure during pancreatitis. In the present study, we measured the changes in the blood-brain barrier (BBB) permeability concomitantly with the determination of serum tumor necrosis factor (TNF) and interleukin-6 (IL-6) levels in rats before, as well as 6, 24 and 48 h after the beginning of intraductal taurocholic acid-induced acute pancreatitis. Cytokine concentrations were measured in bioassays with specific cell lines (WEHI-164 for TNF and B-9 for IL-6), while the BBB permeability was determined for a small (sodium fluorescein, molecular weight (MW) 376 Da), and a large (Evans' blue-albumin, MW 67000 Da) tracer by spectrophotometry in the parietal cortex, hippocampus, striatum, cerebellum and medulla of rats. The serum TNF level was significantly (P < 0.05) increased 6 and 24 h after the induction of pancreatitis, while the IL-6 level increased after 24 and 48 h. A significant (P < 0.05) increase in BBB permeability for both tracers developed at 6 and 24 h in different brain regions of animals with acute pancreatitis. We conclude that cytokines, such as TNF and IL-6, may contribute to the vasogenic brain edema formation during acute pancreatitis.
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PMID:Experimental acute pancreatitis results in increased blood-brain barrier permeability in the rat: a potential role for tumor necrosis factor and interleukin 6. 953 Sep 27


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