Which sign is characteristic of hepatic encephalopathy?

• A. Sleep disturbances
• B. Asterixis
• C. Fetor hepaticus
• D. Elevated ammonia

Answer: (B)

Asterixis, the classic “liver flap,” is the sign most characteristic of hepatic encephalopathy. This flapping tremor of the hands occurs when the patient extends the arms and dorsiflexes the wrists; the brief loss of motor tone causes an involuntary rhythmic tremor. It reflects the brain’s impaired ability to regulate motor function due to the buildup of toxins like ammonia that the damaged liver cannot detoxify.

Sleep disturbances and fetor hepaticus can accompany liver disease, but they’re not as specific to hepatic encephalopathy. Elevated ammonia supports the pathophysiology but is a lab value, not a clinical sign you would observe on a physical exam. So the presence of asterixis on examination is the best indicator of hepatic encephalopathy in this context.