Metabolic encephalopathy

Hazell AS, Todd KG, and Butterworth RE (1998) Mechanisms of neuronal cell death in Wernicke s encephalopathy. Metabolic Brain Diseases 13, 97-122. 

Langlais PJ (1995) Pathogenesis of diencephalic lesions in an experimental model of Wernicke s encephalopathy. Metabolic Brain Diseases 10, 31-44. 

Jaundice, hypoglycaemia, bleeding, encephalopathy, metabolic acidosis and convulsions are followed by cardiovascular collapse, coma and sometimes death 48-60 h after ingestion. 

Pomier-Layrargues G, Rose C, Spahr L, et al. 1998. Role of manganese in the pathogenesis of portal-systemic encephalopathy. Metabol Brain Dis 13 311-317. 

B. After 24-48 hours, when transaminase levels (AST and ALT) begin to rise, hepatic necrosis becomes evident. If acute fulminant hepatic failure occurs, death may ensue. Encephalopathy, metabolic acidosis, and a continuing rise in the prothrombin time (PT) indicate a poor prognosis. Acute renal failure occasionally occurs, with or without concomitant liver failure. 

Provide general supportive care for hepatic or renal failure if it occurs. Emergency liver transplant may be necessary for fulminant hepatic failure. Encephalopathy, metabolic acidosis, hypoglycemia, and progressive rise in the prothrombin time are indications of severe liver injury. 

B. Hepatic failure. Liver injury may be apparent within 24-36 hours, with rapidly rising transaminase levels. Fulminant hepatic failure may follow, with jaundice, encephalopathy, and death. Encephalopathy, metabolic acidosis, severe coagulopathy, and hypoglycemia are grave prognostic signs and usually predict a fatal outcome. 

Schnittger, C., Weissenborn, K., Boker, K., Kolbe, H., Dengler, R., Manns, M.R 1997. Continuous noninvasive cerebral perfusion monitoring in fulminant hepatic failure and brain oedema. In Advances in Hepatic Encephalopathy Metabolism in Liver Disease, eds C. Record and H. A1 Mardini (eds.)., pp. 515-519. New Castle upon Tyne Medical Faculty of the University of Newcastle upon Tyne... 

Thiamin deficiency can result in three distinct syndromes a chronic peripheral neuritis, beriberi, which may or may not be associated with heart ilure and edema acute pernicious (fulminating) beriberi (shoshin beriberi), in which heart failure and metabolic abnormalities predominate, without peripheral neuritis and Wernicke s encephalopathy with KorsakofPs psychosis, which is associated especially with alcohol and dmg abuse. The central role of thiamin diphosphate in... 

Ammonia (NH3) is just one of the toxins implicated in HE. It is a metabolic by-product of protein catabolism and is also generated by bacteria in the GI tract. In a normally functioning liver, hepatocytes take up ammonia and degrade it to form urea, which is then renally excreted. In patients with cirrhosis, the conversion of ammonia to urea is retarded and ammonia accumulates, resulting in encephalopathy. This decrease in urea formation is manifest on laboratory assessment as decreased blood urea nitrogen (BUN), but BUN levels do not correlate with degree of HE. Patients with HE commonly have elevated serum ammonia concentrations, but the levels do not correlate well with the degree of central nervous system impairment.20... 

Callender TJ, Morrow L, Subramanian K, et al. 1993. Three-dimensional brain metabolic imaging in patients with toxic encephalopathy. Environ Res 60 259-319. 

Health effects that have been associated with lead exposures during infancy or childhood include, anemia (Schwartz et al. 1990) (and related disorders of heme synthesis), neurological impairment (e.g., encephalopathy), renal alterations, and colic (Chisolm 1962, 1965 Chisolm and Harrison 1956), and impaired metabolism of vitamin D (Mahaffey et al. 1982 Rosen and Chesney 1983). Death from encephalopathy may occur with PbB levels 125 pg/dL. In addition to the above effects, the following health effects have been associated with lead exposures either in utero, during infancy or during... 

A. M. Herneth, A. Puspok, R. Steindl, and G. Yurdaydin in Advances in Hepatic Encephalopathy and Metabolic Nitrogen Exchange , L. Capocaccia, M. Merli, and O. Riggo, Eds. GRG Press, Boca Raton, 1995, p. 254. 

Zeneroli ML, Iuliano E, Racagni C, Baraldi M Metabolism of gamma-aminobutyric acid and brain uptake in galactosamine induced hepatic encephalopathy. J Neurochem 1982 33 1219-1222. 

Suggested Alternatives for Differential Diagnosis Bartonellosis, brucellosis, other causes of encephalitis, coxsackieviruses, cryptococcosis, cysticercosis, cytomegalovirus, histoplasmosis, legionellosis, leptospirosis, listeria, lyme disease, malaria, rabies, tuberculosis, mumps, stroke, metabolic encephalopathy, Reye syndrome, Bartonella infection, Naegleria infection, Ebstein-Barr virus, prion disease, toxic ingestions, and AIDS. 

The brain has an absolute dependence on the blood for its immediate supply of oxygen and energy substrates. Interruption of oxygen or substrate supply by compromise of pulmonary or cardiovascular function or metabolic factors results in encephalopathy and, if prolonged, neuronal cell death. The brain uses approximately 20% of the total oxygen supply of the body. While glucose remains the primary energy substrate for the brain, alternative substrates maybe used under certain circumstances (see Ch. 31). 

Given the high dependency of cerebral energy production and neurotransmitter synthesis on glucose and oxygen, limitations in supply of these substrates results in metabolic encephalopathy. 

The metabolic encephalopathies comprise a series of neurological disorders not caused by primary structural abnormalities rather, they result from systemic illness, such as diabetes, liver disease and renal failure. Metabolic encephalopathies usually develop acutely or subacutely and are reversible if the systemic disorder is treated. If left... 

There are two major types of metabolic encephalopathy those due to lack of glucose, oxygen or metabolic cofactors (vitamins, for example) and those due to peripheral organ dysfunction. This chapter will review the neurochemistry of the major metabolic encephalopathies, which are listed in Table 34-1. 

FIGURE 34-3 Positron emission tomography using 13NH3 showing increased brain ammonia uptake in a patient with liver cirrhosis and mild hepatic encephalopathy. CMRA, cerebral metabolic ratio for ammonia HE, hepatic encephalopathy PS, permeability/surface area product. (With permission from reference [9].)... 

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