Involuntary jerking movements, especially in the hands, best elicited by having the patient extend the arms, dorsiflex thewrists, and spread the fingers; due to arrhythmic lapses of sustained posture; seen primarily with various metabolic andtoxic encephalopathies, especially hepatic encephalopathy. Syn: flapping tremor.

It is often helpful to stage the hepatic encephalopathy to follow the course of the illness:

* Stage 1: Euphoria/depression, mild confusion, slurred speech, disordered sleep, +/—asterixis

* Stage 2: Lethargy, moderate confusion, +asterixis

* Stage 3: Marked confusion, incoherent speech, sleeping but arousable, +asterixis

* Stage 4: Comatose, -asterixis