What are the stages of hepatic encephalopathy?

Stages of Hepatic Encephalopathy

Hepatic encephalopathy severity is graded using the West Haven Criteria, which divides the spectrum into covert HE (minimal HE and Grade 1) and overt HE (Grades 2-4), with progression from subtle cognitive changes to coma. 1

Severity Classification System

The continuum of HE is divided into distinct stages based on clinical manifestations 1, 2:

Covert Hepatic Encephalopathy

• Minimal HE (MHE): No clinically detectable signs on routine examination; abnormalities only identified through dedicated neuropsychological or neurophysiological testing 2, 3

  • Patients appear normal but have subtle deficits in executive function, psychomotor speed, and attention 3
  • Affects quality of life, driving ability, and increases risk of falls and progression to overt HE 3

• Grade 1: Trivial lack of awareness, shortened attention span, impaired addition or subtraction, altered sleep rhythm (hypersomnia, insomnia, or reversal of sleep-wake cycle), euphoria or anxiety, irritability 2, 4

  • These subtle changes (hypokinesia, psychomotor slowing) are easily overlooked in clinical examination 1

Overt Hepatic Encephalopathy (OHE)

The onset of OHE is marked by disorientation or asterixis, which have good inter-rater reliability 1

• Grade 2: Lethargy or apathy, disorientation to time, inappropriate behavior, obvious personality change, impaired ability to perform mental tasks 2, 4

  • Asterixis (flapping tremor) typically becomes evident at this stage 1

• Grade 3: Somnolence to semi-stupor but responsive to stimuli, confusion, gross disorientation to time and place, bizarre behavior 2, 4

  • Asterixis usually still present 1

• Grade 4: Coma, no response to painful stimuli 2, 4

  • Deep tendon reflexes may diminish or disappear, though pyramidal signs can persist 1

Alternative Grading for Severe Cases

For patients with significantly altered consciousness, the Glasgow Coma Scale (GCS) provides a more operative and robust assessment, evaluating eye opening (1-4), verbal response (1-5), and motor response (1-6), with scores ranging from 3 (deep coma/death) to 15 (fully awake) 1

Clinical Pearls and Pitfalls

Motor and mental signs do not always progress in parallel, creating difficulty in staging severity 1. Key clinical features include:

• Asterixis: Present in early to middle stages (Grades 1-3) but disappears in coma; not pathognomonic as it occurs in uremia and other conditions 1
• Extrapyramidal signs: Hypomimia, rigidity, bradykinesia, parkinsonian-like tremor are common findings 1
• Rare manifestations: Seizures are very rarely reported; transient focal neurological deficits can occur 1

Special Considerations

Type A HE (acute liver failure) has distinct features including risk of increased intracranial pressure and cerebral herniation, requiring different management than Types B and C 1, 2

Complete reversibility is questioned: While traditionally considered fully reversible, research shows that repeated episodes of OHE may cause persistent cumulative deficits in white matter and learning, and some mental deficits may persist even after liver transplantation 1

Diagnostic Approach

The diagnosis requires 1:

• Detection of HE signs in a patient with severe liver insufficiency and/or portosystemic shunting
• Exclusion of alternative causes (metabolic disorders, substance intoxication, infections, electrolyte abnormalities, stroke) 1, 4
• Recognition of precipitating factors (infection, bleeding, constipation, medications) supports the diagnosis 1

Hyponatremia and sepsis can both produce encephalopathy independently and precipitate HE, complicating diagnosis 1, 2