Flapping tremor, also known as asterixis, is a symptom that is closely related to liver diseases. Usually we see him in chronic alcoholics, but that is not a rule.
The cause of asterixis is brain damage caused by liver failure. The condition is called hepatic encephalopathy. Impaired liver function (usually in cirrhotic liver) is associated with reduction of their ability to degrade nitrogen waste products. These waste products arise from proteins and they are partly produced by intestinal bacteria and partly produced by our own metabolism. When the substances accumulate in organism, they cause brain damage. This results in disruption of waking / sleeping cycle, personality disorders, confusion, forgetfulness and eventually unconsciousness and death. In addition, those afflicted have a special type of hand tremor that is known as flapping tremor.
Flapping tremor is most noticeable with arms stretched forward. The brain can not keep the hands in this position and those descend in rapid succession. The patient tries to return hands to desired position and that results in rapid flapping movements.
Tremor will improve if we at least partially solve hepatic encephalopathy. We can do this by indirect methods; our primary goal is to reduce creation of nitrogen wastes products. The patient should limit the intake of proteins in the diet. Usually, we administer laxatives that will speed the passage of stool through intestines, thus reducing the formation of nitrogenous waste products by intestinal bacteria. For the same reason some antibiotics are prescribed to eliminate intestinal flora. The cooperation of patient including absolute alcohol withdrawal is essential. Liver transplant is an ultimate solution, but that is not always possible to accomplish.