Hepatic Encephalopathy

Key points

• Hepatic encephalopathy may be seen in liver disease of any cause. The aetiology is not fully understood but is thought to include excess absorption of ammonia and glutamine from bacterial breakdown of proteins in the gut.
• confusion, altered GCS (see below)
• asterix: 'liver flap', arrhythmic negative myoclonus with a frequency of 3-5 Hz
• constructional apraxia: inability to draw a 5-pointed star
• triphasic slow waves on EEG