Recurrent Non-cirrhotic Hyperammonemic Encephalopathy Due to Complicated Urinary Tract Infection: A Case Report

Hyperammonemic encephalopathy (HE) can be broadly defined as an alteration in the level of consciousness due to elevated blood ammonia level. While hepatic cirrhosis is the most common cause of HE, non-hepatic causes like drugs, infections, and porto-systemic shunts can also lead to the presentation. In this case, we highlight an unusual occurrence of recurrent non-cirrhotic HE from obstructive urinary tract infection (UTI) with urea-splitting micro-organisms in an elderly male patient. The patient exhibited altered mentation, and elevated ammonia levels with normal hepatic function at presentation. Urine culture revealed Proteus mirabilis resistant to extended spectrum beta-lactamases (ESBL). Successful management of obstructive UTI was achieved through Foley's catheterization and intravenous (IV) antibiotics, resulting in the resolution of HE. This outcome further supports the significance of UTI as a potential cause of hyperammonemia. Thus, UTI as one of the non-hepatic causes of hyperammonemia should always be explored among elderly patients presenting with altered mentation.

A Case of Non-cirrhotic Hyperammonemic Encephalopathy in a Patient With Metastatic Gastrointestinal Stromal Tumor

Acute toxic encephalopathy (ATE) is a widely recognized medical emergency with an expansive differential. One particular known etiology for ATE is elevated ammonia, a powerful neurotoxin that often presents with clinical findings of confusion, disorientation, tremors, and in severe cases, coma and death. Hyperammonemia is most commonly associated with liver disease and presents as hepatic encephalopathy in the setting of decompensated cirrhosis; however, in rare cases, a patient may suffer from non-cirrhotic hyperammonemic encephalopathy. We describe the case of a 61-year-old male with metastatic gastrointestinal stromal tumor who was diagnosed with non-cirrhotic hyperammonemic encephalopathy, and briefly explore the literature describing its mechanisms.

A Mysterious Case of Recurrent Acute Hyperammonemic Encephalopathy

Ammonia is a well-recognized neurotoxin. Awareness about hyperammonemia, in the absence of liver cirrhosis, may help in lifesaving, prompt diagnosis, and treatment. We present a case of a 53-year-old male who presented to the emergency department (ED) with altered mental status (AMS). He was unresponsive with occasional eye opening. Initial labs were normal except for mildly elevated blood alcohol level. Serum ammonia levels were very high (305 umol/L). He improved with lactulose. He had similar admissions later on. Urine orotic acid levels were high confirming ornithine transcarbamylase (OTC) deficiency. Noncirrhotic hyperammonemia as a cause of AMS remains a diagnosis of exclusion requiring high index suspicion. Very few cases of late inborn errors of urea cycle disorders (UCDs) have been reported in the literature. Our case highlights the importance of early diagnosis of UCDs and that outcome can be excellent if treated aggressively. Once identified, adult-onset forms of the UCDs have a good prognosis-largely due to the initiation of preventative measures and earlier recognition of exacerbations.

An Intriguing Case of Acute Encephalopathy: Lesson Learned from a Constipated Man

Hyperammonemia is a common cause of encephalopathy encountered in an intensive care unit (ICU). Absence of pre-existing liver disease may misguide a clinician and cases of non-cirrhotic hyperammonemia may be missed in ICU leading to life-threatening outcomes such as cerebral edema and herniation. A critical care physician must look beyond liver cirrhosis as a cause of hyperammonemia so that infrequent but potentially reversible causes of encephalopathy are not missed, and patient treatment is not jeopardized.