Asterixis

Under a asterixis in hepatic injury and flutter tremor (English flapping tremor, of gr a [ privativum ] στήριξις stḗrixis, " in - stable position " ), refers to a grobschlägiges trembling of the hands, especially when toxic or metabolic ( metabolic ) brain damage ( encephalopathy ) occurs. This is not a tremor in the true sense, but a momentary loss of tone of the muscles ( negative myoclonus ) followed by a reflex movement correction. The first description was in 1949 by Adams and Foley.

Causes

The flutter tremor occurs in metabolic encephalopathies, for example, Hepatic encephalopathy, acute liver failure, or Wilson's disease. More rarely, renal failure or drugs may be the cause.

Pathophysiology

The asterixis is emanating from the brain damage symptomatic movement disorder. Through a temporary, short inhibition of extensors ( extensor ) of the forearm muscles comes about a flexion of the hands. The hand falls down and is immediately corrected by a rapid stretching motion in the direction of their initial position. In the legs the Asterixis leads to a disturbance of standing and walking along with falls.

Appearance

The flutter tremor is visible when asking the patient to stretch his arms and with outstretched fingers to hold the hands straight. This results in a grobschlägiger tremor is noticeable, which manifests itself by sudden inflections ( flexion ) of the wrist that occur rhythmically or arrhythmic with a frequency of about 3-5 Hz. This follows a reflex motion correction. When held side arms it looks as if hit with the wings of the patient. The movements usually occur on both sides, but may also exist asymmetric.