Neuroinflammation and neurological alterations in chronic liver diseases

Several million people with chronic liver diseases (cirrhosis, hepatitis) show neurological alterations, named hepatic encephalopathy (HE) with cognitive and motor alterations that impair quality of life and reduces life span. Inflammation acts synergistically with hyperammonemia to induce cognitive and motor alterations in patients with chronic liver disease and minimal hepatic encephalopathy (MHE). Previous studies in animal models have suggested that neuroinflammation is a major player in HE. This would also be the case in patients with liver cirrhosis or hepatitis C with HE. Rats with MHE show microglial activation and neuroinflammation that is associated with cognitive impairment and hypokinesia. The anti-inflammatory drug ibuprofen reduces microglial activation and neuroinflammation and restores cognitive and motor functions in rats with MHE. Chronic hyperammonemia per se induces neuroinflammation. Both peripheral inflammation and hyperammonemia would contribute to neuroinflammation in chronic liver failure. Therefore, neuroinflammation may be a key therapeutic target to improve the cognitive and motor alterations in MHE and overt HE. Identifying new targets to reduce neuroinflammation in MHE without inducing secondary effects would serve to develop new therapeutic tools to reverse the cognitive and motor alterations in patients with HE associated with chronic liver diseases