Psychiatric Manifestations of Hyperammonemic Encephalopathy Following Roux-en-Y Gastric Bypass

Roux-en-Y gastric bypass (RYGB) is considered to be the optimal surgical treatment in the morbidly obese patient and the most common weight loss procedure in the United States. In this case report we describe the life threatening complication of hyperammonemic encephalopathy and its psychiatric presentation in a gastric bypass patient. Hyperammonemic encephalopathy is an extremely uncommon syndrome but also a severe complication of RYGB with only a small number of case reports and high reports of mortality. Early and accurate diagnosis can be easily missed, leading to even further increased morbidity and mortality. Hyperammonemic encephalopathy related to RYGB is a syndrome characterized by life threatening metabolic and laboratory disturbances and associated changes in mental status. Our patient presented with decreased oral intake, malnutrition, weight loss, progressive confusion, markedly diminished memory, and gait instability to an inpatient medical hospitalization. She was found to have the following metabolic derangements including elevated ammonia and orotic acid, deceased ceruloplasmin and albumin, as well as deficiencies in zinc, copper, and selenium. This led to a mental status decline including the inability to respond to verbal stimuli or speak. She was treated with lactulose, rifaximin, levocarnitine, vitamin supplementation, and her ammonia levels began to decline. A naso-jejunal tube was endoscopically placed for enteral feedings, and her mental status began to improve. Over the next two weeks she gradually improved with normalizing of her mental status as evidenced by a Montreal Cognitive Assessment score of 27 out of 30 on day of discharge.