What are the different grades and symptoms of hepatic encephalopathy?

Grades of Hepatic Encephalopathy and Associated Symptoms

Hepatic encephalopathy (HE) should be classified according to the West Haven criteria when temporal disorientation is present (grades ≥2), with the Glasgow Coma Scale added for grades III-IV, while neuropsychological or neurophysiological testing should be used to diagnose covert HE in patients with mild or no neuropsychiatric abnormalities. 1, 2, 3

Classification of Hepatic Encephalopathy

• HE is classified based on the underlying disease type, severity of manifestations, time course, and precipitating factors 1
• Type A HE is due to acute liver failure, Type B is due to portosystemic shunt without significant liver disease, and Type C is due to cirrhosis with or without portosystemic shunt 2, 3
• Based on severity, HE is categorized as covert (minimal HE and Grade I) or overt (Grades II-IV) 2, 3, 4
• According to time course, HE is subdivided into episodic, recurrent (more than one episode over 6 months), or persistent (no return to normal/baseline neuropsychiatric performance between episodes) 2, 1

West Haven Criteria and Symptoms by Grade

Covert Hepatic Encephalopathy

Minimal HE (Grade 0)

• No obvious clinical signs but abnormalities on neuropsychological/neurophysiological tests 3, 4
• Impacts quality of life, driving ability, and increases risk for falls 4
• Requires dedicated psychometric tests rather than clinical assessment 4, 5

Grade I HE

• Mild alterations in consciousness 3, 6
• Subtle personality or behavior changes 3, 6
• Decreased attention and concentration 3, 6
• Sleep disturbances and irritability 3, 6
• Difficulty performing complex cognitive tasks 3, 6
• Psychomotor slowing 1, 5

Overt Hepatic Encephalopathy

Grade II HE

• Lethargy and apathy 6
• Mild disorientation, especially temporal 6
• Inappropriate behavior 6
• Asterixis (flapping tremor) 6
• Dysarthric or slow speech 6
• Evident alterations in psychometric tests 6

Grade III HE

• Somnolence 1, 7
• Disorientation to place 1, 7
• Confusion 1, 5
• Significant cognitive deficits 1
• Bizarre behavior 5
• Glasgow Coma Scale should be added for assessment 1, 2, 3

Grade IV HE

• Coma 1, 5
• Lack of verbal response 1, 7
• Lack of eye response 1, 7
• Lack of motor response 1, 7
• Glasgow Coma Scale assessment is essential 1, 2, 3

Assessment Tools and Considerations

• The Glasgow Coma Scale (GCS) should be used in patients with significantly altered consciousness (Grades III-IV) 1, 2, 3
• GCS evaluates eye, verbal, and motor responses with scores ranging from 3 (deep coma) to 15 (fully awake) 1
• Diagnosis of HE requires exclusion of other causes of altered mental status such as metabolic disorders, medication effects, and neurological conditions 1
• Common precipitating factors include infections, gastrointestinal bleeding, constipation, dehydration, electrolyte disturbances, and sedative medications 2, 6

Clinical Implications

• Covert HE affects patients' quality of life, socioeconomic status, and driving ability 4
• Patients with covert HE have an increased risk of developing overt HE 4, 5
• Recurrent intractable overt HE, together with liver failure, is an indication for liver transplantation 3, 6
• Blood ammonia levels alone do not provide diagnostic, staging, or prognostic value 3, 6

Common Pitfalls in HE Assessment

• Failing to identify and treat precipitating factors, which cause up to 90% of HE cases 6
• Relying solely on ammonia levels for diagnosis or monitoring 3, 6
• Confusing hepatic encephalopathy with other causes of altered mental status 3, 6
• Inadequate assessment of Grade I HE due to its subtle presentation 1, 4
• Not considering secondary prophylaxis after the first episode of overt HE 3, 6