Hepatic Encephalopathy

Excerpt

Hepatic encephalopathy is a potentially reversible syndrome that can occur in individuals with advanced liver dysfunction. It is characterized by a range of neuropsychiatric abnormalities caused by the accumulation of neurotoxic substances in the bloodstream. While it is often associated with preexisting liver conditions like cirrhosis, it can also develop in individuals without prior hepatic issues. In cases without preexisting liver disease, acute severe liver failure can lead to brain swelling and, in severe cases, coma. Hepatic encephalopathy in patients with chronic liver disease can potentially be reversed and managed. However, when it occurs acutely with rapidly increasing blood ammonia levels (fulminant), it becomes more challenging to control due to widespread brain swelling and structural brainstem injuries.

Hepatic encephalopathy symptoms can result from liver insufficiency or the redirection of blood flow away from the liver (portosystemic shunting). According to the consensus of the International Society for Hepatic Encephalopathy and Nitrogen Metabolism, the onset of overt hepatic encephalopathy is defined as the appearance of disorientation or asterixis. Identifying the onset in patients with advanced liver disease can be challenging. Some patients may exhibit subtle signs that can only be detected through specialized tests, a condition referred to as minimal hepatic encephalopathy—observed in as many as 80% of patients with cirrhosis.

Symptoms of hepatic encephalopathy include confusion, personality alterations, disorientation, and reduced consciousness. In the initial stages, a disrupted sleep-wake pattern is often present, where patients tend to sleep during the day and stay awake at night. As the condition progresses through intermediate stages, patients typically encounter increasing levels of confusion, lethargy, and personality shifts. In advanced stages, hepatic encephalopathy can eventually lead to coma, known as hepatic coma or coma hepaticum, which can be fatal. In cases of severe encephalopathy among patients with acute liver failure or known cirrhosis, the mortality rate exceeds 50% within the first year.