Hyperammonemia-induced encephalopathy: A rare devastating complication of bariatric surgery

Table 1 Laboratory investigations and imaging at time of hospitalization

Laboratory investigation/imaging	Values
BMP	Within normal limits (Cr 1.0 mg/dL)
CBC	Within normal limits (platelets 158 K/μL)
Iron panel	Within normal limits
Hepatic panel	AST 30 U/L
	ALT 9 U/L
	Alkaline phosphatase 52 U/L
	Total Bilirubin 0.9 mg/dL
Urine orotic acid	1.4 mmol/mol of creatinine
Ammonia level	155 mcg/dL
Carnitine level, zinc, manganese, vitamin B12, vitamin A, vitamin D	Within normal limits
Abdominal ultrasound	No evidence of liver disease or cirrhosis
MRI brain	No acute or chronic intracranial abnormalities

MRI: Magnetic resonance imaging; BMP: Basic metabolic panel; CBC: Complete blood count; AST: Aspartate aminotransferase; ALT: Alanine aminotransferase.

Table 2 Etiology of hyperammonemia of non-hepatic origin[21]

Age	Category	Examples
Adults	Stressful events	-
	Partial enzyme deficiency	-
	Infection	Urinary tract infections (urease-producing organism, such as proteus mirabilis)
Pediatrics	Medications	Valproate
		Topiramate
		Salicylates such as aspirin
		Acetazolamide
		Zonisamide
		High-dose chemotherapy (5-fluorouracil)
	Infection	Urinary tract infections (urease-producing organism, such as proteus mirabilis)
	Organic acidemias	Isovalericacidemia, propionic acidemia, methylmalonicacidemia, glutaricacidemia type II, multiple carboxylase deficiency, beta-ketothiolase deficiency
	Congenital lactic acidosis	Pyruvate dehydrogenase deficiency
		Pyruvate carboxylase deficiency
		Mitochondrial disorders
	Fatty acid oxidation defects	Acyl CoA dehydrogenase deficiency
		Systemic carnitine deficiency
	Dibasic aminoacid transport defects	Lysinuric protein intolerance
		Hyperammonemia-hyperornithinemia-homocitrullinuria
	Miscellaneous	Transient hyperammonemia of the newborn asphyxia
		Reye syndrome
		Lactic acidosis