Department of Medicine, Hepatology and Gastroenterology Section, Imperial College London, St Mary's Hospital Campus, London.
Hepatic encephalopathy is a serious and potentially fatal complication of both acute and chronic liver disease, arising as a result of hepatocellular failure, cirrhosis and/or portal-systemic shunting (Ferenci et al, 2002). It reflects a broad spectrum of neuropsychiatric abnormalities, encompassing a range of defects in psychomotor, locomotive, cognitive, emotional and behavioural functions (Prakash and Mullen, 2010). Hepatic encephalopathy is either overt or minimal. While overt hepatic encephalopathy can be diagnosed using bedside clinical tests, minimal hepatic encephalopathy is clinically invisible and requires psychometric testing to diagnose. The rising prevalence of end-stage viral hepatitis-related liver disease, coupled with the growing problem of alcoholic and non-alcoholic fatty liver disease, has significantly increased the burden of disease from cirrhosis (Mooney et al, 2007; Fleming et al, 2008), so recognition and appropriate management of the manifestations of decompensating cirrhosis (including hepatic encephalopathy) is essential. Hepatic encephalopathy has a substantial societal burden because of its impact on survival, quality of life and daily functioning, including an impaired ability to drive, leaving patients especially vulnerable to road traffic accidents (Ferenci et al, 2002; Prakash and Mullen, 2010).