Case Report
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Hepatol. May 8, 2015; 7(7): 1007-1011
Published online May 8, 2015. doi: 10.4254/wjh.v7.i7.1007
Hyperammonemia-induced encephalopathy: A rare devastating complication of bariatric surgery
Michelle L Kromas, Omar Y Mousa, Savio John
Michelle L Kromas, Department of Anesthesiology, SUNY Upstate Medical University, Syracuse, NY 13210, United States
Omar Y Mousa, Savio John, Department of Medicine, SUNY Upstate Medical University, Syracuse, NY 13210, United States
Author contributions: Kromas ML and Mousa OY participated in patient care and initial evaluation, diagnosis, and follow-up of patient as described in report; Kromas ML, Mousa OY and John S analyzed the laboratory and imaging findings and conducted review of previous publications and wrote the paper.
Ethics approval: The case report was deemed to meet criteria for exemption from review by SUNY Upstate Medical University Institutional Review Board.
Informed consent: The patient provided informed verbal consent for inclusion in case report at time of discharge from hospital.
Conflict-of-interest: The authors including Michelle L Kromas, Omar Y Mousa, Savio John have no conflicts of interest to disclose including but not limited to receipt of research funding, fees for service as speakers, or owning shares or stocks in any organizations.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Omar Y Mousa, MD, Department of Medicine, SUNY Upstate Medical University, 750 East Adams Street, Syracuse, NY 13210, United States.
Telephone: +1-315-4644480 Fax: +1-315-4644484
Received: December 16, 2014
Peer-review started: December 17, 2014
First decision: January 8, 2015
Revised: January 26, 2015
Accepted: March 16, 2015
Article in press: March 18, 2015
Published online: May 8, 2015

The clinical manifestations of hyperammonemia are usually easily identifiable to the clinician when associated with liver disease and lead to prompt diagnosis and treatment. However, hyperammonemia-induced encephalopathy is rare in adults in the absence of overt liver disease, thus diagnosis is often delayed or missed leading to potentially life threatening complications. Without proper treatment, such patients can decompensate rapidly with poor outcomes including seizures, coma, and death. Early assessment of plasma ammonia levels in patients with normal hepatic function and characteristic symptoms of encephalopathy can lead to early intervention while investigating the underlying etiology. We describe a patient who presented with a 2-year progression of waxing and waning acute mental status changes after a Roux-en-Y gastric bypass surgery. He was found to have elevated ammonia level as well as orotic aciduria; results consistent with a urea cycle disorder. After consulting neurology as well as toxicology, he ultimately improved after dietary protein restriction, sodium benzoate and lactulose therapy. While rare, clinicians should have a high index of suspicion for late onset urea cycle disorders in symptomatic patients presenting with encephalopathy secondary to hyperammonemia.

Keywords: Hyperammonemia, Urea cycle, Bariatric surgery, Encephalopathy, Hepatic

Core tip: Encephalopathy secondary to hyperammonemia in the absence of hepatic dysfunction presents a diagnostic dilemma to many clinicians. As such, early and accurate diagnosis can be easily missed, leading to increased morbidity and mortality. We describe a case of adult onset urea cycle disorder presenting with encephalopathy after gastric bypass surgery. Although this challenging diagnosis is rare, treatment is inexpensive and readily available. Thus early recognition and intervention can prevent the rapid decline that may occur if the diagnosis is unrecognized.