What are the signs of hepatic encephalopathy in an adult patient with a history of liver disease?

Signs of Hepatic Encephalopathy

Hepatic encephalopathy presents with a wide spectrum of neuropsychiatric and motor abnormalities ranging from subtle cognitive deficits detectable only by psychometric testing to overt disorientation, asterixis, and coma. 1

Cognitive and Behavioral Signs

Minimal/Covert Hepatic Encephalopathy

• Impaired psychometric testing is the only manifestation, affecting attention, working memory, psychomotor speed, and visuospatial ability 1
• Sleep-wake disturbances with excessive daytime sleepiness occur frequently, though complete sleep-wake reversal is less common 1
• These subtle changes affect up to 80% of cirrhotic patients and severely impact driving ability, work performance, and fall risk 2

Progressive Mental Status Changes

• Personality changes including apathy, irritability, and disinhibition are reported by relatives as encephalopathy progresses 1
• Disorientation to time and space marks the onset of overt hepatic encephalopathy according to ISHEN consensus 1
• Inappropriate behavior and acute confusional states with either agitation or somnolence develop 1
• Stupor and coma represent the most severe manifestations 1

Motor and Neurological Signs

Asterixis (Flapping Tremor)

• Asterixis is a negative myoclonus (loss of postural tone), not a true tremor, present in early to middle stages before stupor 1
• Elicited by hyperextension of wrists with separated fingers or rhythmic squeezing of examiner's fingers 1
• Can also be observed in feet, legs, arms, tongue, and eyelids 1
• Not pathognomonic for hepatic encephalopathy—also occurs in uremia 1

Pyramidal Signs

• Hypertonia, hyperreflexia, and positive Babinski sign are common in noncomatose patients 1
• Deep tendon reflexes may paradoxically diminish or disappear in coma, though pyramidal signs persist 1
• Transient focal neurological deficits can rarely occur 1
• Seizures are very rarely reported in hepatic encephalopathy 1

Extrapyramidal Dysfunction

• Hypomimia, muscular rigidity, bradykinesia, and hypokinesia are common findings 1
• Monotony and slowness of speech with parkinsonian-like tremor 1
• Dyskinesia with diminished voluntary movements 1
• Involuntary movements resembling tics or chorea occur rarely 1

Important Clinical Caveats

Discordant Progression

• Mental and motor signs may not progress in parallel in individual patients, creating difficulty in staging severity 1
• Some patients exhibit predominantly cognitive dysfunction while others show more prominent motor abnormalities 1

Hepatic Myelopathy

• A particular pattern with severe motor abnormalities exceeding mental dysfunction, possibly related to marked portosystemic shunting 1
• Characterized by paraplegia with progressive spasticity and weakness of lower limbs with hyperreflexia 1
• Does not respond to standard ammonia-lowering therapy but may reverse with liver transplantation 1

Differential Diagnosis Challenges

• Normal blood ammonia level in suspected hepatic encephalopathy should prompt consideration of alternative diagnoses 1
• Brain imaging should be performed in every patient with chronic liver disease and unexplained altered brain function to exclude structural lesions 1
• Symptoms overlap with septic encephalopathy, uremia, hyponatremia, thiamine deficiency (especially in alcoholic liver disease), and direct alcohol neurotoxicity 1
• Thiamine should be given IV before glucose-containing solutions when Wernicke's encephalopathy cannot be excluded 1

Precipitating Factors Context

• Neurological symptoms occur in 21-33% of cirrhotic patients with sepsis and 60-68% with septic shock 1
• Infection, gastrointestinal bleeding, constipation, electrolyte disturbances, and medication non-compliance commonly precipitate overt episodes 3, 4