Grade 0 Hepatic Encephalopathy
Grade 0 hepatic encephalopathy means the complete absence of any neurological or neuropsychiatric symptoms in a patient with liver disease—no detectable cognitive impairment on clinical examination or psychometric testing. 1
Definition and Classification Context
Grade 0 represents the baseline state where patients with cirrhosis have no hepatic encephalopathy at all. 1 This is distinct from the broader spectrum of hepatic encephalopathy, which ranges from:
- Grade 0: No hepatic encephalopathy whatsoever 1
- Minimal HE: Cognitive impairment detectable only by specialized psychometric or neurophysiological testing, not by clinical examination 1
- Grade 1 HE: Mild clinical signs detectable on examination (impaired calculation ability, subtle personality changes, sleep disturbances) 1, 2
- Grades 2-4: Overt hepatic encephalopathy with progressively worsening confusion, disorientation, and ultimately coma 1
Clinical Significance
The West Haven Classification uses a binary approach in practice: grades 0-1 are considered "no overt HE," while grades 2-4 constitute "overt HE." 1 However, within the "no overt HE" category, there is critical distinction:
- Some patients truly have no HE at all (grade 0) 1
- Others have minimal HE (detectable only by testing) 1
- Still others have grade 1 HE (mild clinical signs) 1
The French guidelines note significant overlap between minimal HE and grade 1 HE due to lack of a reference diagnostic method and the fluctuating course of the condition. 1 This has led some experts to merge these into "covert HE," though this terminology remains controversial in the field. 1, 3
Screening Recommendations
All patients with cirrhosis should be screened for hepatic encephalopathy regardless of liver function status, even if they appear to be grade 0. 1 This is critical because:
- Covert HE (minimal + grade 1) affects more than two-thirds of patients with cirrhosis, with some studies showing prevalence up to 85% 1
- The presence of even minimal HE predicts onset of overt HE and is associated with poorer prognosis 1
- Early identification allows intervention before progression to overt stages 1, 4
Management Implications
Patients who are truly grade 0 (no HE) require:
- Ongoing surveillance for development of covert or overt HE 1
- No specific HE treatment at this stage 1
- Attention to preventing precipitating factors (infections, GI bleeding, constipation, dehydration, sedatives) 2, 5
Primary prophylaxis to prevent first episodes of overt HE is not required for grade 0 patients, except in those with known high risk factors. 1