Inherited and Acquired Syndromes of Hyperammonemia and Encephalopathy in Children

Department of Pediatrics, University of Connecticut School of Medicine, Hartford.
Seminars in Liver Disease (Impact Factor: 4.95). 09/1994; 14(3):236-58. DOI: 10.1055/s-2007-1007315
Source: PubMed
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    • "Ammonia affects both excitatory and inhibitory synaptic transmission in the mammalian brain through a variety of mechanisms [3]. The clinical features of hyperammonemia are usually nonspecific in adults and include vomiting, lethargy, sleep and behavioral disturbances, hallucinations, delusions and psychosis [4], coma and death [2]. The greatest disadvantage of the currently available potent conventional or synthetic antihyperammonemic agents/therapies lies in their toxicity and reappearance of symptoms after discontinuation. "
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    ABSTRACT: The present study was aimed to investigate the antioxidant potential of Momordica charantia fruit extract (MCE) in ammonium chloride-induced (AC) hyperammonemic rats. Experimental hyperammonemia was induced in adult male Wistar rats (180-200 g) by intraperitoneal injections of ammonium chloride (100 mg kg(-1) body weight) thrice a week. The effect of oral administration (thrice a week for 8 consecutive weeks) of MCE (300 mg kg(-1) body weight) on blood ammonia, plasma urea, serum liver marker enzymes and oxidative stress biomarkers in normal and experimental animals was analyzed. Hyperammonemic rats showed a significant increase in the activities of thiobarbituric acid reactive substances, hydroperoxides and liver markers (alanine transaminase, aspartate transaminase and alkaline phosphatase), and the levels of glutathione peroxidase, superoxide dismutase, catalase and reduced glutathione were decreased in the liver and brain tissues. Treatment with MCE normalized the above-mentioned changes in hyperammonemic rats by reversing the oxidant-antioxidant imbalance during AC-induced hyperammonemia, and offered protection against hyperammonemia. Our results indicate that MCE exerting the antioxidant potentials and maintaining the cellular integrity of the liver tissue could offer protection against AC-induced hyperammonemia. However, the exact underlying mechanism is yet to be investigated, and examination of the efficacy of the active constituents of the M. charantia on hyperammonemia is desirable.
    Evidence-based Complementary and Alternative Medicine 01/2010; 2011(8). DOI:10.1093/ecam/nep227 · 1.88 Impact Factor
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    • "However, an elevation in serum ammonia level above 200 mmols/L is more commonly seen in inborn errors of metabolism like urea cycle defects and branch chain organic acidaemias, although rarely other conditions may cause such high blood levels [25]. Although, hyperammonemia is thought to be associated with liver disease, most cases present with normal liver function [10] [26]. Mild and transient hyperammonemia can often be asymptomatic and is usually triggered by protein loads and catabolic states [13]. "
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    ABSTRACT: Valproic acid and its derivatives are commonly used to treat many psychiatric conditions in the elderly. Hyperammonemia is a less common but important side effect of these drugs. The elderly patient appears highly vulnerable to this side effect of this group of medications. In this paper, we systematically review the published literature for hyperammonemia induced by valproic acid and its derivatives. We describe the three reported cases and review possible treatment strategies for this condition.
    Case Reports in Medicine 02/2009; 2009(1687-9627):802121. DOI:10.1155/2009/802121
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    • "Reye syndrome, a disorder of unknown cause, is characterized by acute encephalopathy and fatty degeneration of the liver and it is usually characterized by a history of preceding viral illness or the use of aspirin during viral infections [10]. Many children with metabolic disorders present with Reye-like syndrome episodes, usually at a young age and/or with a positive past or family history suspicious for an inborn error of metabolism [11]. It has been reported as a presenting sign of type I 3-MGC aciduria and in a few cases of mitochondrial cytopathies in older children [12,13]. "
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    ABSTRACT: Hyperammonemia, hypoglycemia, hepatopathy, and ventricular tachycardia are common presenting features of carnitine-acylcarnitine translocase deficiency (Mendelian Inheritance in Man database: *212138), a mitochondrial fatty acid oxidation disorder with a lethal prognosis. These features have not been identified as the presenting features of mitochondrial cytopathy in the neonatal period. We describe an atypical presentation of mitochondrial cytopathy in a 2 day-old neonate. She presented with a Reye-like syndrome episode, premature ventricular contractions and ventricular tachycardia. Initial laboratory evaluation exhibited a large amount of 3-methylglutaconic acid on urine organic acid analysis, mild orotic aciduria and a nonspecific abnormal acylcarnitine profile. The evaluation for carnitine-acylcarnitine translocase deficiency and other fatty acid oxidation disorders was negative. The patient later developed a hypertrophic cardiomyopathy and continued to be affected by recurrent Reye-like syndrome episodes triggered by infections. A muscle biopsy exhibited signs of a mitochondrial cytopathy. During the course of her disease, her Reye-like syndrome episodes have subsided; however, cardiomyopathy has persisted along with fatigue and exercise intolerance. This case illustrates that, in the neonatal period, hyperammonemia and ventricular tachycardia may be the presenting features of a lethal carnitine-acylcarnitine translocase deficiency or of a mitochondrial cytopathy, associated with a milder clinical course. This association broadens the spectrum of presenting phenotypes observed in patients with disturbed mitochondrial energy metabolism. Also, the presence of 3-methylglutaconic aciduria suggests mitochondrial dysfunction and mild orotic aciduria could potentially be used as a marker of mitochondrial disease.
    BMC Pediatrics 01/2003; 2(1):12. DOI:10.1186/1471-2431-2-12 · 1.93 Impact Factor
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