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

After a careful characterization, a rat model of fulminant hepatic failure galactosamine-induced was utilized in order to evaluate the neurochemical changes and the histological alterations which occur during the developing of the encephalopathy. Following these studies, normal rats were treated with toxins claimed to be the primary agents of hepatic encephalopathy to recognize those which are able to mimic the behavioral, electrophysiological and neurochemical changes found in the rat model of fulminant hepatic failure. With the limit due to informations coming from an experimental model, the symptoms of HE seem to be attributable to neurotoxic agents such as ammonia. The toxicity of ammonia does not seem to be due to a mere decrease of general brain metabolism, but seems rather to be mediated by an increase, at least in some compartment, of neurotoxic amino acids such as glutamate. Both accumulation of ammonia and the neurotoxic effect of glutamate seem to be potentiated by the described zinc depletion (both in liver and in brain). Hence the final effect of these phenomena is the development of the symptoms of encephalopathy triggered by an imbalance between inhibitory and excitatory receptor systems in the brain associated with neuronal alterations which take place early and before the appearance of brain edema.
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PMID:Neurotransmission in hepatic encephalopathy. 196 5

Since antiviral chemotherapy is available herpes encephalitis has become of great importance among viral affections of the central nervous system. Five young infants are presented with special problems of this disease and its diagnostic possibilities especially serological and imaging methods (CT scan, nuclear magnetic resonance tomography, ultrasonography of the brain) as well as electroencephalography. Clinical symptoms are very important since all those methods are not sufficient for early diagnosis and prompt onset of antiviral chemotherapy. Herpes encephalitis should be considered after apparent febrile seizures with focal symptoms as well as increasing disturbance of consciousness as manifestation of acute encephalopathy.
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PMID:[Herpes encephalitis in infancy]. 322 93

Fourteen of 330 patients treated with melarsoprol (Mel B) for human African trypanosomiasis (HAT) developed a severe reactive arsenical encephalopathy (RAE). Six of these cases were fatal and postmortem examination was performed on 5 patients. Symptoms of "sleeping sickness" were compared with symptoms after treatment with arsenicals and the subsequent onset of RAE. There are 3 characteristic syndromes of RAE: convulsive status associated with acute cerebral edema, rapidly progressive coma without convulsions, and acute nonlethal mental disturbances without neurological signs. Three subjects revealed hypoxic brain damage with acute cerebral edema, and multiple hemorrhages of brain stem in those comatose. The pathology of the underlying HAT (chronic perivascular inflammation and plasma cytic infiltration of the brain) and the pathology of the RAE (characterized by acute vasculitis) are distinct. RAE occurs in the first as well as in the second stage (CNS involvement) of trypanosomiasis but the reason for this is unclear; an exclusive toxicity of the drug, or a Herxheimer reaction are possible but seem unlikely. Both clinical and laboratory findings point rather to a drug-related, delayed immune response.
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PMID:Clinical and pathological aspects of human African trypanosomiasis (T. b. gambiense) with particular reference to reactive arsenical encephalopathy. 394 40

Retrospective assessment of hepatic and central nervous system involvement associated with chickenpox cases at a large metropolitan medical center reveals that 28 of 58 patients had biochemical, but not inflammatory, evidence of liver involvement. An additional 18 patients had biochemical liver abnormalities along with non-inflammatory encephalopathy (Reye syndrome) and 12 had clear evidence of central nervous system inflammatory involvement (encephalitis). There were no cases of solitary inflammatory liver involvement. Reviewed evidence suggests that the pathogenesis of hepatopathy and hepatoencephalopathy (Reye syndrome) is not caused by replication of virus in the involved organs, but instead is mediated through a cytotoxic mechanism and that the inflammatory brain disease is also not caused by viral replication in brain tissue, but appears to be tissue damage associated with immune cell responses (post-infectious encephalitis). The concept put forth in this essay is that a virus replicating in one organ (skin) could affect the macromolecular function of cells in another organ (liver, brain) bringing about both hepatopathy and hepatoencephalopathy.
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PMID:Chickenpox encephalitis and encephalopathy: evidence for differing pathogenesis. 629 9

Ammonia metabolism in Reye syndrome was studied by quantitative analysis of the time course of hyperammonemia and the urinary excretion of ammonia, urea, and total nitrogen. These measures were then utilized to assess the effect of citrulline administration in 8 patients compared to results in 22 patients managed without citrulline. Two indices of the severity and duration of hyperammonemia correlated strongly with mortality: the half-time for decline of hyperammonemia and the area under the hyperammonemia curve (an index of the total burden of ammonia presented to the brain). These results suggest that the total amount of ammonia delivered to brain may be important to the pathogenesis of encephalopathy. Citrulline-treated patients had more severe disease at admission and greater abnormalities in indices of nitrogen and ammonia metabolism, though the latter did not reach significance. The urine ammonia/urea nitrogen excretion ratio, an index of the efficiency of ammonia conversion to urea, normalized more rapidly in the citrulline-treated group, evidence that citrulline may have improved urea cycle function. Overall mortality did not differ in the two groups. The deaths of 2 citrulline-treated patients in this small group were attributable to factors unrelated to treatment, however, so the possible effect of citrulline on mortality was not definitively tested. No indication was found that citrulline was harmful, nor that it increased ammonia levels.
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PMID:Ammonia metabolism in Reye syndrome and the effect of citrulline. 705 28

The detection of neurodegenerative and neurometabolic diseases in children relies on a high index of suspicion as most will present as common paediatric problems such as recurrent vomiting, feeding problem, failure to thrive, sepsis, or developmental delay. Alternatively, children may present with an acute encephalopathy or with a chronic progressive encephalopathy. Clinical clues suggestive of neurometabolic disorders include encephalopathic features such as microcephaly, macrocephaly, developmental regression, developmental arrest, change in sensorium, seizures, hypotonia, hypertonia, abnormal eye signs; also extrapyramidal or cerebellar signs and systemic features like abnormal respiration, hepatosplenomegaly, abnormal hair, liver dysfunction, renal tubular dysfunction, cardiomyopathy, and feeding difficulties or growth problems. Initial screening include tests for acidosis, ketosis, hyperlacticemia, and hyperammonemia. Further investigations should amino acid chromatography, assays of organic acids, specific enzyme assay of white cell or fibroblast culture, and histopatholgy of cell and tissue biopsy (white blood cell, skin, muscle, conjunctiva, bone marrow, liver, rectum, or brain). The correct diagnosis holds implications for targeted therapeutic intervention, genetic counselling, and possibly, prenatal diagnosis.
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PMID:Neurodegenerative diseases in children. 1184 61

Accumulation of albumin-bound toxins is known to occur in liver failure, and to variable extents is responsible for the associated end-organ dysfunctions (kidney, circulation, brain). The toxin-binding and scavenging functions of albumin are exploited in albumin dialysis for removal of these toxins. The extracorporeal liver support device known as molecular adsorbents recirculating system (MARS) is based on dialysis across an albumin-impregnated membrane, using 20% albumin as dialysate. Charcoal and anion exchange resin columns in the circuit help cleanse and regenerate the dialysate. Clinical studies over the last few years have demonstrated proven reduction in hyperbilirubinaemia, along with an improvement in encephalopathy, systemic haemodynamics and renal function in liver failure patients, as well as apparent improvement in survival. The results of larger controlled clinical trials, as well as studies investigating the pathophysiological basis of its effect, are awaited.
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PMID:Liver failure: basis of benefit of therapy with the molecular adsorbents recirculating system. 1279 44

Malformations of the cerebral cortex (MCC) are often associated with severe epilepsy and developmental delay. About 40% of drug-resistant epilepsies are caused by MCC. Classification of MCC is based on embryological brain development, recognising forms that result from faulty neuronal proliferation, neuronal migration and cortical organisation. Hemimegalencephaly, an enlarged dysplastic hemisphere, can present as early onset severe epileptic encephalopathy or as partial epilepsy. In focal cortical dysplasia (FCD), MRI shows focal cortical thickening and simplified gyration. Patients have drug-resistant, often early onset epilepsy. Complete surgical ablation of FCD is accompanied by remission in up to 90% of patients, but may be technically difficult. Tuberous sclerosis (TS) is a multisystemic disorder primarily involving the nervous system; 60% of patients having epilepsy, with 50% having infantile spasms. TS is caused by mutations in the TSC1 and TSC2 genes; 75% of cases are sporadic. TSC1 mutations cause a milder disease. Bilateral periventricular nodular heterotopia (BPNH) consists of confluent and symmetric nodules of grey matter along the lateral ventricles. X-linked BPNH presents with epilepsy in females and prenatal lethality in most males. Most patients have partial epilepsy. Filamin A mutations have been reported in families and sporadic patients. Lissencephaly (LIS smooth brain) is a severe MCC characterised by absent or decreased convolutions. Classical LIS is quite rare and manifests with severe developmental delay, spastic quadriparesis and severe epilepsy. XLIS mutations cause classical lissencephaly in hemizygous males and subcortical band heterotopia in heterozygous females. Thickness of heterotopic band and degree of pachygyria correlate well with phenotype severity. Schizencephaly (cleft brain) has a wide anatomo-clinical spectrum, including partial epilepsy in most patients. Polymicrogyria (excessive number of small and prominent convolutions) has a wide spectrum of clinical manifestations ranging from early onset epileptic encephalopathy to selective impairment of cognitive functions. Bilateral perisylvian polymicrogyria may be familial. Patients present with faciopharingo-glosso-masticatory diplegia and epilepsy, which is severe in about 65% of patients.
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PMID:Epilepsy and malformations of the cerebral cortex. 1461 17

The accumulation of albumin-bound toxins in liver failure is believed to be responsible for the development of associated end-organ dysfunctions (kidney, circulation, brain). Albumin dialysis utilizes the scavenging functions of albumin for the removal of toxins. The Molecular Adsorbents Recirculating System (MARS) is one such extracorporeal liver support device where blood is dialyzed across an albumin-impregnated membrane against 20% albumin. Charcoal and anion exchange resin columns in the circuit cleanse and regenerate the albumin dialysate. Clinical studies in the last decade have demonstrated proven reduction in hyperbilirubinemia, along with an improvement in encephalopathy in liver failure patients, as well as apparent improvement in survival. Some studies have also reported improvement of systemic hemodynamics and renal function in these patients. Amelioration of intractable pruritus and treatment of toxicities with albumin-bound substances are some of the newer indications emerging. However, the specific underlying pathophysiological mechanisms are still not clear. Two other systems based on the removal of albumin-bound toxins, the Prometheus (using the principle of fractionated plasma separation and adsorption [FPSA]), and the single pass albumin dialysis (SPAD) are also currently under development but available clinical data are limited.
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PMID:Emerging indications for albumin dialysis. 1566 9

Hypoxia-ischemia is a common cause of neonatal brain injuries. Nitric oxide (NO) is upregulated in the brain after hypoxia-ischemia and generally believed to exert a paradoxical effect on neurons, neurodestruction and neuroprotection, but it has not been demonstrated that NO is actually neuroprotective in neonatal hypoxic-ischemic encephalopathy. We evaluated the effect of intracerebroventricular administration of nipradilol (3,4-dihydro-8-(2-hydroxy-3-isopropylamino)-propoxy-3-nitroxy-2H-1-benzopyran), a potent NO donor, at various concentrations (0.1 muM to 1 mM in 5 mul PBS/brain) to neonatal rats with hypoxic-ischemic treatment. The extent of the infarct area in the brain was significantly reduced by injection of the 1 muM nipradilol solution. However, denitro-nipradilol (3,4-dihydro-8-(2-hydroxy-3-isopropylamino)-propoxy-3-hydroxy-2H-1-benzopyran), that does not release NO, did not show the neuroprotective effect, suggesting that NO released from nipradilol exerts a neuroprotective effect on neonatal neurons.
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PMID:Neuroprotective effect of nipradilol, an NO donor, on hypoxic-ischemic brain injury of neonatal rats. 1715 52


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