Portosystemic Shunt Leading to Encephalopathy in a Non-Cirrhotic Patient

While portal-systemic encephalopathy is a common entity in cirrhotic patients, it is less frequent in non-cirrhotic patients. We are reporting a case of a 68-year-old female who presented with unresponsiveness for the second time in six months. She underwent extensive evaluation for liver disease with ultrasonography and computerized tomography of the abdomen, testing for causes of liver disease including testing for viral hepatitis was negative. A liver biopsy was done clearing any doubt about the presence of significant liver disease or clinically significant portal hypertension. With absence of liver disease hence lower likelihood of portal-systemic encephalopathy (PSE) we evaluated for other causes of encephalopathy with unremarkable neuroimaging including brain MRI and head CT, unremarkable CSF analysis and EEG showing no seizure activity. Given the negative workup and the high ammonia level with the significant clinical response to ammonia lowering therapy we further evaluated the patient for other causes of PSE with Doppler ultrasonography of the liver and eventually angiography of the portal system with the high suspicion for a portosystemic shunt as a cause of her encephalopathy. A shunt from the inferior mesenteric vein to the left renal vein was diagnosed and successfully occluded utilizing coil embolization. The patient recovered normal mentation and was eventually discharged home. This case sheds light on the importance of diagnosing portosystemic shunts leading to encephalopathy, as occlusion of the shunt can correct the encephalopathy and help prevent further episodes.