A184 NON-CIRRHOTIC HYPERAMMONEMIA SECONDARY TO EXTRAHEPATIC PORTOSYSTEMIC VENOUS SHUNT PRESENTING AS A CONGNITIVE DYSFUNCTION: A CASE REPORT AND LITERATURE REVIEW

Background Hyperammonemia secondary to liver disease is a very common cause of hepatic encephalopathy (HE) and it is easily recognized in patients with advanced liver disease. Non-cirrhotic causes of hyperammonemia are rare, particularly extrahepatic portosystemic venous shunts (EPS). The majority of these shunts are between a mesenteric vein and the inferior vena cava. We report a case of a non-cirrhotic hyperammonemia secondary to a shunt between the superior mesenteric vein (SMV) and the right renal vein (RRV) that presented with encephalopathy. Diagnosis was delayed due to lack of awareness of non-cirrhotic hyperammonemia underscoring the importance of measuring ammonia in all patients presenting with encephalopathic symptoms irrespective of their liver function.