Refractory hepatic encephalopathy in a patient with hypothyroidism: Another element in ammonia metabolism

Abstract

Hepatic encephalopathy (HE) remains a diagnosis of exclusion due to the lack of specific signs and symptoms. Refractory HE is an uncommon but serious condition that requires the search of hidden precipitating events (i.e., portosystemic shunt) and alternative diagnosis. Hypothyroidism shares clinical manifestations with HE and is usually considered within the differential diagnosis of HE. Here, we describe a patient with refractory HE who presented a large portosystemic shunt and post-ablative hypothyroidism. Her cognitive impairment, hyperammonaemia, electroencephalograph alterations, impaired neuropsychological performance, and magnetic resonance imaging and spectroscopy disturbances were highly suggestive of HE, paralleled the course of hypothyroidism and normalized after thyroid hormone replacement. There was no need for intervention over the portosystemic shunt. The case findings support that hypothyroidism may precipitate HE in cirrhotic patients by inducing hyperammonaemia and/or enhancing ammonia brain toxicity. This case led us to consider hypothyroidism not only in the differential diagnosis but also as a precipitating factor of HE.

Two novel CPS1 mutations in a case of carbamoyl phosphate synthetase 1 deficiency causing hyperammonemia and leukodystrophy

“…As the superabundant ammonia can enter the central nervous system and exerts its toxic effects on the brain, hepatic encephalopathy can also be detected as a complication of hyperammonemia. 16,17 MRI data of the patient are reported in our study which is always absent in other reports because of untimely diagnosis and limited lifetime of patients with CPS1D. Moreover, as a crucial activator of CPS1 by producing N-acetylglutamate, defects in N-acetylglutamate synthase (NAGS) gene can also lead to similar metabolize dysfunction.…”

“…Therefore, marked hyperammonemia and decreased downstream production of the urea cycle can be observed in patients with CPS1D. As the superabundant ammonia can enter the central nervous system and exerts its toxic effects on the brain, hepatic encephalopathy can also be detected as a complication of hyperammonemia . MRI data of the patient are reported in our study which is always absent in other reports because of untimely diagnosis and limited lifetime of patients with CPS1D.…”

Beyond MELD Predictors of Post TIPSS Acute Liver Failure the Lesson Learned

“…Till date there have been only few (eight) case reports on hypothyroidism causing hyperammonemic coma and all except one were patients of CLD. 11 This further emphasizes that hypothyroidism precipitates hyperammonemia of liver dysfunction. However, none of them was post TIPSS creation though spontaneous portosystemic shunt has existed in one of these case reports.…”

Lights and Shadows in Hepatic Encephalopathy Diagnosis

“…It should be considered that the distinction between precipitants and confounders is not always simple or clear. Some factors such as sepsis, hyponatremia, and hypothyroidism, which function as precipitants (because they intervene in the mechanisms of ammonia production or toxicity), can also alter brain function per se, as occurs in patients without liver failure [ 41 , 42 , 43 , 44 ]. Treatment should be directed at these factors and not only at hyperammonemia [ 8 ].…”