UMEM Educational Pearls

Category: Neurology

Title: Asterixis

Keywords: asterixis, liver failure, elevated ammonia, flapping tremor (PubMed Search)

Posted: 9/3/2008 by Aisha Liferidge, MD (Updated: 4/26/2024)
Click here to contact Aisha Liferidge, MD

  • Asterixis is a tremor of the wrist that occurs when the wrist is extended (dorsiflexed).
  • It is also often referred to as a "flapping tremor" or "liver flap."
  • Asterixis results from arrhythmic, interrruptions of voluntary muscle contraction resulting in brief lapses in posture.
  • It is most often associated with hepatic encephalopathy that results from abnormal metabolism of ammonia to urea, causing brain cell damage.  The subsequent elevated levels of ammonia are due to liver failure.
  • In addition to hepatic enephalopathy, asterixis can also be associated with the following conditions:

               -- azotemia

               -- cardon dioxide toxicity

              -- metabolic encephalopathies

              -- Wilson's Disease