Hepatic encephalopathy (HE) is characterized by hepatic dysfunction and a multitude of potentially reversible neuropsychiatric changes, including impaired neuromuscular function and cognitive defects. HE is frequently associated with worsening acute liver failure, advanced cirrhosis, and TIPS (transjugular intrahepatic portal-systemic shunts). Patients typically have stigmata of underlying chronic liver disease, including jaundice, ascites, spider telangiectasias, and muscle wasting.
Overt HE is defined by inattention, personality change, prolonged reaction time, impaired working memory, asterixis, myoclonus, and, if severe, possible progression to coma. Patients can appear parkinsonian with rigidity, bradykinesia, shuffling gait, and tremor. Alternatively, minimal HE may be present in up to 80% of cirrhotic patients and is characterized by subtle cognitive changes. The spectrum of changes is frequently graded according to the West Haven criteria:
Grade 1 includes mild decreased attention span, hypersomnia, a slowness of thinking, mood changes, and slight confusion;
Grade 2 includes lethargy, disorientation (especially to time), dysarthria, asterixis, and personality changes;
Grade 3 includes disorientation to time and place, somnolence, disordered speech, memory impairment, and marked confusion;
Grade 4 progresses to coma.
HE may be precipitated by infection (spontaneous bacterial peritonitis or urinary tract infection), gastrointestinal (GI) bleeding, electrolyte abnormalities, and renal failure, among many possibilities. While the exact pathophysiology is unknown, it is believed that neurotoxins are not properly filtered from the blood as the disease advances. These include ammonia and false neurotransmitters such as octopamine and tyramine, as well as mercaptans and manganese. These contaminants then lead to changes in neuropsychiatric functioning.
ICD10CM: K72.91 – Hepatic failure, unspecified with coma
SNOMEDCT: 13920009 – Hepatic Encephalopathy
Differential Diagnosis & Pitfalls
Differential includes any cause of confusion, including:
Drugs / toxins (eg, opioids, antipsychotics, drugs of abuse, poisons)
Below is a list of drugs with literature evidence indicating an adverse association with this diagnosis. The list is continually updated through ongoing research and new medication approvals. Click on Citations to sort by number of citations or click on Medication to sort the medications alphabetically.