Which term is described as a metabolic encephalopathy-related flapping tremor?

• A. A&O
• B. Vertigo
• C. Asterixis
• D. Saddle anesthesia

Answer: (C)

Asterixis is the flapping tremor seen in metabolic encephalopathy. It’s a brief, involuntary loss of postural muscle tone that causes the hands to flap when the wrists are held dorsiflexed. This negative motor phenomenon is most commonly associated with hepatic encephalopathy but can occur with other metabolic derangements that affect brain function. In practice, you test it by asking the patient to hold their arms out with wrists extended; the characteristic irregular, rapid flapping confirms asterixis.

A&O describes orientation and mental status, not a movement abnormality; vertigo is a spinning sensation pointing to vestibular or central causes of dizziness; saddle anesthesia refers to loss of sensation in the perineal region, indicating cauda equina or nerve root issues.