Asterixis (also called the flapping tremor, or liver flap) is arrhythmic interruptions of sustained voluntary muscle contraction causing brief lapses of posture, with a frequency of 3–5 Hz. It is bilateral, but may be asymmetric. Unilateral asterixis may occur with structural brain disease. 1. It can be a sign of hepatic encephalopathy, damage to brain cells presumably due to the inability of the liver to metabolize ammonia to urea. The cause is thought to be predominantly related to abnormal am