Asterixis

Infobox_Disease
Name = PAGENAME


Caption =
DiseasesDB = 33950
ICD10 = ICD10|R|27|8|r|25
ICD9 = ICD9|781.3
ICDO =
OMIM =
MedlinePlus =
eMedicineSubj =
eMedicineTopic =
MeshName = Asterixis
MeshNumber = C10.597.350

Asterixis (also called the flapping tremor) is a tremor of the wrist when the wrist is extended (dorsiflexion), sometimes said to resemble a bird flapping its wings. Also called "liver flap", it can be a sign of hepatic encephalopathy, damage to brain cells due to the inability of the liver to metabolize ammonia to urea. The cause is thought to be related to abnormal ammonia metabolism. The term derives from the Greek "a", "not" and "stērixis", "fixed position".

Usually there are brief, .arrhythmic interruptions of sustained voluntary muscle contraction causing brief lapses of posture, with a frequency of 3-5 Hz. It is bilateral, but may be asymmetric. Asterixis is seen most often in drowsy or stuporous patients with metabolic encephalopathies, especially in decompensated cirrhosis or acute hepatic failure. It is also seen in some patients with renal failure and azotemia, and in carbon dioxide toxicity. It can also be a feature of Wilson's disease.

R.D. Adams and J.M. Foley first described asterixis in 1949 in patients with severe liver failure and encephalopathy. [Adams RD, Foley JM. The neurological changes in the more common types of severe liver disease. Trans American Neurology Association 1949; 74: 217-219.]

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* [http://escuela.med.puc.cl/paginas/publicaciones/Guias/DHC/imagenes/paginas_f/dhc_f40.html Diagram]