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Hyperammonemic Coma—Barking Up the Wrong Tree

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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.

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Acknowledgments

The case has been presented as a poster in the congress of the European Federation of Internal Medicine—EFIM 2005, Paris, August 31 to September 3, 2005: poster no. 1945.

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Correspondence to Doron Rimar MD.

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Rimar, D., Kruzel-Davila, E., Dori, G. et al. Hyperammonemic Coma—Barking Up the Wrong Tree. J GEN INTERN MED 22, 549–552 (2007). https://doi.org/10.1007/s11606-007-0131-6

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  • DOI: https://doi.org/10.1007/s11606-007-0131-6

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