Hepatic encephalopathy (HE) is dysfunction of the brain resulting from liver insufficiency and/or portal-systemic blood shunting. Depending on the etiology, three types of HE have been described: Type A due to acute liver failure, Type B due to porto-systemic shunts but with no liver dysfunction and type C in patients with liver cirrhosis.In this review, the author has discussed the approach to a patient highlighting the definition, clinical grading and diagnostic principles, with particular reference to type C HE. Precipitating factors include infection, GI bleeding, constipation, electrolyte disorder, dehydration, overdose of diuretics. Clinical presentation of HE ranges from neurological or psychiatric abnormalities to coma.

The West Haven criteria are the most commonly used tool to grade the severity of HE. Based on these criteria, four grades of clinically evident HE have been defined. A fifth grade, subclinical or minimal HE, was subsequently added because of patients who had alterations in brain function but no clinical signs of HE. It has been suggested that MHE and grade I HE be categorized as covert HE and grades 2 to 4 as overt HE. Diagnosis is a challenge as neither the symptoms nor the neuropsychological changes are specific to HE. Also, there are no specific diagnostic imaging modalities. Hence, HE is diagnosed only after other causes of encephalopathy have been ruled out.

Response to treatment confirms the diagnosis.