Hyperammonemia in children: on the crossroad of different disorders

Neurologist. 2012 Sep;18(5):261-5. doi: 10.1097/NRL.0b013e318266f58a.

Abstract

Background: Symptoms of hyperammonemia occur in patients irrespective of the kind of metabolic diseases. Age, metabolic and nutritional status, and decompensation factors such as infections influence clinical manifestations. Prolonged, untreated hyperammonemia leads to brain injury and intellectual disability. Treatment is directed at lowering plasma ammonia. Brain ammonium concentrations are 1.5 to 3.0 times higher than that in blood.

Review summary: The authors discuss the pathophysiology of the symptoms and consequences of hyperammonemia in children, focusing on the metabolic disorders leading to an increased level of ammonia.

Conclusions: Ammonia toxicity has been investigated for a long time. According to the main hypotheses, the neurological alterations are connected to alterations in glutamatergic neurotransmission.

Publication types

  • Review

MeSH terms

  • Amino Acid Metabolism, Inborn Errors / complications
  • Amino Acid Metabolism, Inborn Errors / diagnosis
  • Amino Acid Metabolism, Inborn Errors / physiopathology
  • Brain / physiopathology*
  • Child
  • Diagnosis, Differential
  • Hepatic Insufficiency* / complications
  • Hepatic Insufficiency* / diagnosis
  • Hepatic Insufficiency* / physiopathology
  • Humans
  • Hyperammonemia* / diagnosis
  • Hyperammonemia* / etiology
  • Hyperammonemia* / physiopathology
  • Metabolism, Inborn Errors* / complications
  • Metabolism, Inborn Errors* / diagnosis
  • Metabolism, Inborn Errors* / physiopathology
  • Mitochondrial Diseases / complications
  • Mitochondrial Diseases / diagnosis
  • Mitochondrial Diseases / physiopathology
  • Reye Syndrome / complications
  • Reye Syndrome / diagnosis
  • Reye Syndrome / physiopathology