asterixis
Pronunciation: as-ter-IK-sis
A tremor consisting of involuntary jerking movements caused by brief lapses in muscle tone, often described as a "flapping tremor."
Full Definition
Asterixis is a neurological sign characterized by brief, irregular lapses of sustained muscle contraction, resulting in intermittent dropping or flapping movements, most commonly observed when the patient extends their arms and dorsiflexes their wrists. This sign is frequently associated with metabolic encephalopathies, particularly hepatic encephalopathy, but can also be seen in uremic encephalopathy, hypercapnia, and certain medication toxicities. The term derives from Greek meaning "not fixed" and is an important clinical marker for editors to recognize in neurological assessments and case reports.
Usage
Usage note: Often incorrectly referred to as a tremor when it is actually a negative motor phenomenon caused by brief muscle tone lapses.
In Context
- "The patient demonstrated bilateral asterixis when asked to extend his arms with wrists dorsiflexed." — Neurological examination report
- "Asterixis was noted on physical examination, prompting further investigation for hepatic encephalopathy." — Clinical case study