title: Hyperammonemic coma--barking up the wrong tree.
abstract: Hepatic encephalopathy and myxedema coma share clinical features: coma, ascites, anemia, impaired liver functions, and a "metabolic" electroencephalogram (EEG). Hyperammonemia, a hallmark of hepatic encephalopathy, has also been described in hypothyroidism. Differentiation between the 2 conditions, recognition of their possible coexistence, and the consequent therapeutic implications are of utmost importance. We describe a case of an 82-year-old woman with a history of mild chronic liver disease who presented with hyperammonemic coma unresponsive to conventional therapy. Further investigation disclosed severe hypothyroidism. Thyroid hormone replacement resulted in gain of consciousness and normalization of hyperammonemia. In patients with an elevated ammonia level, altered mental status, and liver disease, who do not have a clear inciting event for liver disease decompensation, overwhelming evidence of hepatic decompensation, or who do not respond to appropriate therapy for hepatic encephalopathy, hypothyroidism should be considered and evaluated.
authors: The Ruth and Bruce Rappaport Faculty of Medicine, Department of Medicine, Carmel Medical Center, Technion-Israel Institute of Technology, Haifa, Israel. doronrimar@gmail.com
authors: Doron
authors: D
authors: Rimar
authors: Eti
authors: E
authors: Kruzel-Davila
authors: Guy
authors: G
authors: Dori
authors: Elzbieta
authors: E
authors: Baron
authors: Haim
authors: H
authors: Bitterman
mesh_terms: D000369:Aged, 80 and over; D003128:Coma / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D003937:Diagnosis, Differential; D005260:Female; D006501:Hepatic Encephalopathy / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology; D006801:Humans; D022124:Hyperammonemia / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D007037:Hypothyroidism / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology