The pathophysiology of hepatic encephalopathy.
Hepatic encephalopathy (HE) is a complicated disorder, the pathophysiology of which remains to be fully understood. This article reviews the current main theories including the potential involvement of ammonia, gamma-aminobutyric acid (GABA)/benzodiazipines and false neurotransmitters. Each theory is critically examined with the evidence for each reviewed carefully, and the potential relationship of ammonia to the remaining two theories explored. Known preciptating factors of HE are also considered as evidence. The conclusions drawn from the evidence provided indicate the large role played by ammonia and suggest that this may be the key to understanding HE as science progresses.
ICU, St. James Hospital, Leeds, UK. vrfaint@aol.com
Victoria
V
Faint
D024322:Amino Acids, Aromatic / Q000378:metabolism; D000597:Amino Acids, Branched-Chain / Q000172:deficiency / Q000378:metabolism; D000641:Ammonia / Q000378:metabolism*; D001923:Brain Chemistry; D006471:Gastrointestinal Hemorrhage / Q000150:complications; D006501:Hepatic Encephalopathy / Q000145:classification / Q000209:etiology / Q000378:metabolism* / Q000503:physiopathology*; D006801:Humans; D007239:Infections / Q000150:complications; D007674:Kidney Diseases / Q000150:complications; D015985:Precipitating Factors; D011963:Receptors, GABA-A / Q000378:metabolism*; D012720:Severity of Illness Index; D014883:Water-Electrolyte Imbalance / Q000150:complications; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D024322:Amino Acids, Aromatic; D000597:Amino Acids, Branched-Chain; D011963:Receptors, GABA-A; D005680:gamma-Aminobutyric Acid; D000641:Ammonia