Valproate is widely used because of broad spectrum of action, but it can produce an encephalopathy resulting from hyperammonemia even at the therapeutic range of valproate and is called as valproate-induced encephalopathy (VHE). Delay in recognition of VHE can result in the development of potentially life-threatening complications. Fortunately, it is reversible with discontinuing valproate. A 65-year-old man became progressively lethargic with impaired gait and poor cognitive function while taking valproate as alternative to zonisamide. Routine investigations of admission profiles were performed but revealed no abnormalities. Next, we checked serum ammonia level to identify other possible causes and detected hyperammonemia despite the therapeutic range of valproate in the absence of any abnormalities in liver enzymes. On cessation of valproate, he has achieved dramatic clinical improvement including the reversal of hyperammonemia. We confirmed the diagnosis of VHE. This emphasizes the importance of rapid diagnosis and proper management of VHE in order to prevent the neurological damage and minimize complications.
Aged ; Ammonia ; Gait ; Humans ; Hyperammonemia ; Isoxazoles ; Liver ; Valproic Acid

Seventeen dogs were treated with L-ornithin-L-aspartate (LOLA; experimental group). Three dogs were treated with lactulose recognized therapy (control group). Following LOLA administration, 15 dogs experienced a significant decrease in ammonia level (p < 0.05) and showed clinical signs of improvement. However, there were no clinical signs of improvement in two dogs, even though the ammonia level decreased. Conversely, the clinical signs of the control group also improved and the ammonia level decreased, although these changes were not significant (p > 0.05). These results suggest that LOLA is an effective drug to treat hyperammonemia in veterinary medicine.
Ammonia ; Animals ; Dogs* ; Dipeptides* ; Hepatic Encephalopathy* ; Hyperammonemia ; Lactulose ; Veterinary Medicine

Neonatal hyperammonemia is a disorder of ammonia metabolism that occurs in the neonatal period. It is a clinical syndrome characterized by abnormal accumulation of ammonia in the blood and dysfunction of the central nervous system. Due to its low incidence and lack of specificity in clinical manifestations, it is easy to cause misdiagnosis and missed diagnosis. In order to further standardize the diagnosis and treatment of neonatal hyperammonemia, the Youth Commission, Subspecialty Group of Neonatology, Society of Pediatrics, Chinese Medical Association formulated the expert consensus based on clinical evidence in China and overseas and combined with clinical practice experience,and put forward 18 recommendations for the diagnosis and treatment of neonatal hyperaminemia.
Humans ; Infant, Newborn ; Ammonia ; China ; Consensus ; Hyperammonemia/therapy*

Transient hyperammonemia in a newborn is an overwhelming disease manifested by hyperammonemic coma. The majority of affected newborns are premature and have mild respiratory syndrome. The diagnosis may be difficult to determine. This metabolic disorder is primarily characterized by severe hyperammonemia in the postnatal period, coma, absence of abnormal organic aciduria and normal activity of the enzymes of the urea cycle. Hyperammonemic coma may develop within 2-3 days of life, although its etiology is unknown. Laboratory studies reveal marked hyperammonemia (>4,000 micromol/L). The degree of neurologic impairment and developmental delay in this disorder depends on the duration of hyperammonemic coma. Moreover, the infant may succumb to the disease if treatment is not started immediately and continued vigorously. Hyperammonemic coma as a medical emergency requires dialysis therapy. Here, we report a case of severe transient hyperammonemia in a preterm infant (35 week of gestation) presented with respiratory distress, seizure, and deep coma within 48 hours and required ventilatory assistance and marked elevated plasma ammonia levels. He survived with aggressive therapy including peritoneal dialysis, and was followed 2 years later without sequelae.
Ammonia ; Coma ; Dialysis ; Emergencies ; Humans ; Hyperammonemia ; Infant ; Infant, Newborn ; Infant, Premature ; Peritoneal Dialysis ; Plasma ; Seizures ; Urea

BACKGROUND: Differential diagnosis between a generalized tonic-clonic seizure and syncope may be difficult due to similar clinical features. The need for a biological marker to distinguish a seizure from syncope has been emphasized from past studies. Transient hyperammonemia could be an indicator of recent convulsive seizure. The purpose of this study is to review the use of plasma ammonia level in the differential diagnosis of seizure and syncope. METHODS: Adult patients who were admitted to the Department of Neurology at Gangnam Severance Hospital with final diagnosis of a generalized tonic-clonic seizure or syncope were eligible for this study. Plasma ammonia levels were checked within 8 hr after an insult. RESULTS: Among the patients with a loss of consciousness who underwent analysis of plasma ammonia level, diagnoses were made with a seizure (n=65) and syncope (n=38). The seizure group had 70.29+/-70.86 micromol/L and the syncope group had 28.37+/-10.27 micromol/L of ammonia level, respectively. The seizure group presented with a significantly increased plasma ammonia (p<0.05) compared to the syncope group. The cut-off value with the reliable diagnostic level was defined as 36 micromol/L (=61.308 microg/dL) with a sensitivity of 0.65 and specificity of 0.80 by receiver operating characteristic (ROC) curve analysis. CONCLUSIONS: Plasma ammonia measurement during acute post-ictal period may be a useful test for the identification and the differential diagnosis of seizures and syncope.
Adult ; Ammonia ; Biomarkers ; Diagnosis, Differential ; Humans ; Hyperammonemia ; Neurology ; Plasma ; ROC Curve ; Seizures ; Sensitivity and Specificity ; Syncope ; Unconsciousness

5-Fluorouracil (5-FU) is a chemotherapeutic agent commonly used in the treatment of a variety of solid tumors. Common adverse effects of fluorouracil chemotherapy include diarrhea, mucositis and myelosuppression. However, neurologic toxicities including hyperammonemic encephalopathy are rare and not well recognized. Transient hyperammonemic encephalopathy related to continuous infusion of high-dose 5-FU has rarely been reported. We report four cases of transient hyperammonemic encephalopathy in patients receiving continuous infusion of 5-FU. The mentality of all patients was altered during or just after the infusion of 5-FU. There were no focal neurological signs, laboratory excluding hyperammonemia or radiological abnormalities. After patients received adequate hydration and repeated lactulose enema, the mental status completely recovered within one or two days, and serum ammonium level subsequently returned to normal. In conclusion, we suggest that a transient hyperammonemic encephalopathy should be considered in differential diagnosis of patients receiving continuous 5-FU infusion with altered mentality.
Ammonium Compounds ; Diagnosis, Differential ; Diarrhea ; Drug Therapy ; Enema ; Fluorouracil* ; Humans ; Hyperammonemia ; Lactulose ; Mucositis

3-Methylcrotonyl-CoA carboxylase(MCC) is a biotin-dependent enzyme involved in the leucine metabolism. We describe a patient with MCC deficiency who manifested with Reye syndrome-like illness with status epilepticus, metabolic acidosis, hypoglycemia, hyperammonemia, elevated liver enzymes and neurologic impairments after a viral gastroenteritis and then suffered from Lennox-Gastaut syndrome. Urinary organic acid analysis revealed increased excretions of 3-hydroxyisovaleric acid and 3-methylcrotonylglycine. This patient was managed with a leucine restriction diet and supplementation of biotin and carnitine, which was not so effective. He suffered from neurologic sequelae such as Lennox-Gastaut syndrome, motor and cognitive impairements.
Acidosis ; Biotin ; Carnitine ; Diet ; Gastroenteritis ; Humans ; Hyperammonemia ; Hypoglycemia ; Leucine ; Liver ; Metabolism ; Status Epilepticus

Acute hyperammonemia is a medical emergency in the newborn. Efficient, prompt removal of serum ammonia is essential in preventing irreversible brain damage in order to prevent the profound central nervous system dysfunction due to hyperammonia. We report a case of 2.3 kg, 5-day old girl with methylmalonic acidemia who presented with severe hyperammonemia and was successfully treated with continuous venovenous hemodiafiltration(CVVHDF). CVVHDF is an effective and safe method of ammonia removal in the newborn.
Ammonia ; Brain ; Central Nervous System ; Emergencies ; Female ; Hemodiafiltration* ; Humans ; Hyperammonemia* ; Infant, Newborn

The clinical syndrome of hyperammonemic encephalopathy is often encountered in the context of decompensated liver disease. Although it is rare in patients without hepatic disease, non-hepatic causes cannot be excluded. Anesthesiologists should be careful in choosing the anesthetic agent and perioperative management for hyperammonemic patients in order to avoid acute hyperammonemia and encephalopathy. We report successful general anesthesia during GDC (Guglielmi detachable coil) embolization for a large unruptured aneurysm in the right distal internal carotid artery in a female patient with hyperammonemic encephalopathy that was caused by a portal-systemic shunt.
Anesthesia ; Anesthesia, General ; Aneurysm ; Carotid Artery, Internal ; Female ; Hepatic Encephalopathy* ; Humans ; Hyperammonemia ; Intracranial Aneurysm* ; Liver Diseases

Citrullinemia type I is an urea cycle defect caused by mutations in the argininosuccinate synthetase (ASS1) gene. We report a novel argininosuccinate synthetase gene mutation in a Korean family with type I citrullinemia. Metabolic evaluation revealed significant hyperammonemia. Amino acid/acylcarnitine screening using tandem mass spectrometry showed high level of citrulline. Plasma amino acid analysis showed high level of citrulline and the urine organic acid analysis showed makedly increased level of orotic acid. To confirm diagnosis of citrullinemia we did mutation analysis of the ASS1 gene. The patient was found to have mutations of c.689G>C (p.G230A) and c.892G>A (p.E298K), which were new types of argininosuccinate synthetase gene mutation have never been reported in Korea. We report a novel case of argininosuccinate synthetase 1 gene mutation and suggest that the gene study to the family members is necessary to carry out when a patient is diagnosed as citrullinemia.
Argininosuccinate Synthase ; Citrulline ; Citrullinemia ; Humans ; Hyperammonemia ; Korea ; Mass Screening ; Orotic Acid ; Plasma ; Tandem Mass Spectrometry ; Urea