Unusual Case of Hyperammonemic Encephalopathy in Elderly Patient Without Liver Disease

Here we describe a case of an 87-year-old man who was admitted to the hospital with clinical evidence of encephalopathy and was found to have hyperammonemia. Abdominal ultrasound (US) with color doppler showed a rare vascular anomaly consisting in a shunting of portal blood flow directly into the systemic circulation. Abdominal computed tomography scan with contrast injection was performed and revealed a spontaneous intrahepatic porto-systemic shunt (SIHPSS). Portosystemic shunts are rare and often detected in adulthood but should be considered an important cause of unexplained encephalopathy in the absence of cirrhotic liver disease or hepatic trauma. This case illustrates that, albeit rare, SIHPSS may express themselves for the first time in the elderly, a patient population that is frequently affected by many more common causes of altered mental status. Our patient was treated with medical conservative therapy which led to an impressive amelioration of his symptoms.