Hyperammonemia Questions & Answers

Updated: Nov 09, 2018
  • Author: Jasvinder Chawla, MD, MBA; Chief Editor: Tarakad S Ramachandran, MBBS, MBA, MPH, FAAN, FACP, FAHA, FRCP, FRCPC, FRS, LRCP, MRCP, MRCS  more...
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Questions & Answers

Overview

What is hyperammonemia?

What are the signs and symptoms of early-onset hyperammonemia (neonates)?

What are the signs and symptoms of late-onset hyperammonemia (late in life)?

What is the clinical presentation of infants with hyperammonemia?

How are physical exam findings characterized in patients with hyperammonemia?

Which lab tests are indicated in suspected hyperammonemia?

Which imaging studies are used in the workup of hyperammonemia?

What are the treatment goals in hyperammonemia?

Which medications are used in the treatment of hyperammonemia?

What are the management approaches to hyperammonemia aside from medication?

What is the role of transplantation in the treatment of hyperammonemia?

What is the physiology of ammonia and how does hyperammonemia cause neurological disorders?

What is the pathophysiology of hyperammonemia?

What is the mechanism of ammonia neurotoxicity that results in hyperammonemia?

What is the role of astrocyte morphology in hyperammonemia?

What are the manifestations of high levels of ammonia that may result in hyperammonemia?

How are the neurochemical disturbances in chronic hyperammonemia characterized?

What is the role of RNA oxidation in hyperammonemia?

What is the relationship between hyperammonemia and anorexia?

What is the incidence of hyperammonemia in the US?

What is the prevalence of hyperammonemia internationally?

What are the morbidities associated with hyperammonemia?

What are the race-related demographics of hyperammonemia?

What are the sex-related demographics of hyperammonemia?

What are the age-related demographics of hyperammonemia?

Presentation

What is the importance of family history in hyperammonemia?

What is the presentation of early-onset hyperammonemia?

What is the presentation of late-onset hyperammonemia?

How does hyperammonemia present in infants?

What unusual physical exam findings are associated with hyperammonemia in infants?

How is Reye syndrome associated with hyperammonemia characterized?

Which enzyme defects in the urea cycle are associated with hyperammonemia?

What is the role of organic acidemias in hyperammonemia?

Which organic acidemias are associated with hyperammonemia?

How is congenital lactic acidosis characterized in relation to hyperammonemia?

Which lactic acidosis disorders are associated with hyperammonemia?

Which fatty acid oxidation defects are associated with hyperammonemia?

Which dibasic amino acid transport defects are associated with hyperammonemia?

How is transient hyperammonemia of the newborn characterized?

What is the relationship between asphyxia and hyperammonemia in newborns?

How does valproate cause hyperammonemia?

What is the role of topiramate/valproate in the development of hyperammonemia?

Does carbamazepine cause hyperammonemia?

Does chemotherapy cause hyperammonemia?

Does aspirin cause hyperammonemia?

Why are children with epilepsy at increased risk for hyperammonemia?

What is the role of liver disease in hyperammonemia?

Which chronic liver diseases cause hyperammonemia?

How do renal conditions cause hyperammonemia?

What are other causes of hyperammonemia?

Which lab studies are used in the workup of neonates with suspected hyperammonemia?

Which acidemias are associated with hyperammonemia?

What causes hyperammonemia with respiratory alkalosis?

How is transient hyperammonemia of the newborn characterized?

Which conditions should be considered in the differential diagnosis of late-onset hyperammonemia?

DDX

What are the differential diagnoses for Hyperammonemia?

Workup

Which lab tests are used in the workup of hyperammonemia?

Which imaging studies are used in the workup of hyperammonemia?

Which histologic findings are associated with hyperammonemia?

Treatment

What are the treatment goals in hyperammonemia?

How is neonatal hyperammonemic coma treated?

How is intercurrent hyperammonemia treated?

What are the surgical options for treatment of hyperammonemia?

Which specialist consultations are indicated in the treatment of hyperammonemia?

What is the dietary management strategy in hyperammonemia?

Should activity be restricted in patients with hyperammonemia?

Medications

What are the medication recommendations for patients with hyperammonemia?

Which medications in the drug class Antiemetic are used in the treatment of Hyperammonemia?

Which medications in the drug class Urea Cycle Disorder Treatment Agents are used in the treatment of Hyperammonemia?

Follow-up

How are children with hyperammonemia monitored on an outpatient basis?

What is the approach to inpatient care of hyperammonemia?

Which medications are used in the treatment of hyperammonemia?

When is transfer indicated for hyperammonemia?

What information on signs and symptoms of hyperammonemia should be provided to parents?

What are the complications of hyperammonemia?

What is the prognosis of hyperammonemia?