Clinicians have a new sign commonly called the "liver flap" or "flapping tremor," described as a characteristic type of involuntary movement or "peculiar intermittency of sustained muscle contraction." While primarily a useful sign of impending liver failure it has also been observed in patients with uremia, polycythemia vera, severe malnutrition, and steatorrhea. In addition, the sign has been found in some patients with azotemia without hepatic disease. It is emphasized that this type of tremor although characteristic of, is not solely diagnostic of, impending or existing hepatic failure.
Smythe CM, Baroody NB. HEPATIC-TYPE "FLAPPING TREMOR" OCCURRING IN PATIENTS WITHOUT HEPATIC DISEASE. JAMA. 1957;165(1):31-34. doi:10.1001/jama.1957.02980190033008