Asthenia and fatigue in hyperammonemia: etiopathogenesis and methods of correction

Abstract

Asthenia and fatigue are the most common syndromes in patients with liver disease, which significantly affects their quality of life. The prevalence of fatigue in chronic liver diseases is from 50% to 85%. While some progress has been made in understanding the processes that can cause fatigue in general, the underlying causes of fatigue associated with liver disease remain not well understood. In particular, many data suggest that fatigue associated with liver disease likely results from changes in neurotransmission in the brain against the background of hyperammonemia. Hyperammonemia is a metabolic state characterized by an increased level of  ammonia, a  nitrogen-containing compound. The  present review describes hyperammonemia, which is likely important in the pathogenesis of fatigue associated with liver disease. Ammonia is a potent neurotoxin, its elevated blood levels can cause neurological signs and symptoms that can be acute or chronic, depending on the  underlying pathology. Hyperammonemia should be recognized early, and immediately treated to prevent the development of life-threatening complications, such as, swelling of the brain and coma. The article gives pathophysiological mechanisms of influence of hyperammonemia on state of psychovegetative status of patients with liver diseases, also lists basic principles of treatment. A significant part of the article is devoted to L-ornithine-L-aspartate, which is effective in asthenia and fatigue to reduce the level of hyperammonemia through a variety of well-studied mechanisms in chronic liver diseases.