Hepatic encephalopathy

Hepatic encephalopathy (HE) is a neuropsychiatric disorder which can appear as a complication of acute or chronic liver disorders. Pathophysiologically the disorder is a clinical manifestation of a low-grade chronic cerebral edema, which leads to changes in astrocytic function with disturbances of glioneuronal communication. The findings point to a disturbance of cerebral oscillatory networks in HE that is triggered by possible neurotoxic- and hydration-sensitive, thalamic structures and results in an abnormally low-frequency and rigid thalamocortical and corticomuscular coupling. While the diagnosis of high-grade HE will be done exclusively by the clinical picture, psychometric and neurophysiological tests are necessary to diagnose the low-grade forms. Yet, the analysis of the critical flicker frequency (CFF) has been shown to be an easy and simple semi-quantitative test procedure for the quantification and follow-up of neuropsychiatric deficits in HE. The recognition and consequent treatment of the precipitating factors are the most important therapeutic measures. These are complemented by dietetic and pharmaceutical treatment.