Differential Diagnosis of Hepatic Encephalopathy
Mr. H had multiple conditions that can present with mental status changes: a psychotic illness; cocaine, opiate, and alcohol use disorders; and chronic liver disease with a history of hepatic encephalopathy. To diagnose hepatic encephalopathy, it must be distinguished from these and other causes of mental status change, and the overlapping presenting symptoms and interplay between schizophrenia and advanced liver disease must be considered in diagnostic and treatment approaches (Figure 1). General indicators that may suggest delirium or encephalopathy rather than decompensation of a primary psychiatric disorder include a sudden and dramatic change in mental status, an underlying medical illness, visual hallucinations, fluctuating levels of consciousness, and the acute onset of new or different psychiatric symptoms with a known history of prior psychiatric illness (25). Such indicators may overlap with substance intoxication or withdrawal states, so toxicology screening is imperative. Atypicality of psychotic symptoms (e.g., predominant visual hallucinations) and temporal association with worsening laboratory indices may be useful in distinguishing exacerbations of a primary psychotic illness from secondary psychoses, such as psychosis caused by hepatic encephalopathy (26). For Mr. H, worsening hepatic encephalopathy was often associated with the emergence of visual hallucinations and delusional misidentification in the setting of increasing confusion, while exacerbations of schizophrenia were mostly characterized by increased frequency and intensity of auditory hallucinations.