Asterixis.

Asterixis is a type of negative myoclonus characterized by irregular lapses of posture of various body parts. It is an uncommon but important sign in clinical neurology. Initially described as a "liver flap," its utility encompasses a galaxy of neurological and nonneurological situations. Asterixis has a rich history. Despite being described over 70 years ago, its exact pathogenesis remains unknown. Its significance as a tool for the evaluation and prognosis of encephalopathies has been suggested. This review presents its history, clinical implications and its significance.