Portosystemic encephalopathy

Portosystemic or type C hepatic encephalopathy (HE) is a frequent complication and an indicator of a worsening prognosis in patients with liver cirrhosis. It is characterized by alterations in cognition, consciousness, and motor function. Usually type C HE occurs episodically. However, a few patients also present with chronic progressive symptoms of central nervous system dysfunction. In these cases motor symptoms most often exceed cognitive dysfunction and alterations of consciousness. The most frequent features of these chronic progressive forms of HE are acquired hepatocerebral degeneration and hepatic myelopathy. Current hypotheses about the pathophysiology of type C HE are based on the finding that symptoms occur in the presence of hyperammonemia, especially, but are amplified by accompanying factors such as inflammation, hyponatremia, or the application of benzodiazepines, for example. Accordingly, therapy aims at the reduction of ammonia production and absorption, and, since most of the HE episodes are provoked by nutritional protein overload, gastrointestinal bleeds, infection, medication (especially sedatives or diuretics) or constipation, by treatment of the provoking factor. Of note, this approach does not work in acquired hepatocerebral degeneration and hepatic myelopathy. Here liver transplantation should be considered early in the course of the disease.