Two Cases of Hemodialysis-associated Chronic Portal-systemic Shunt Encephalopathy (CPSE) with Opposite Changes in the Blood Ammonia Concentrations during Hemodialysis: A Case Report and Literature Review.

The onset of hyperammonemia due to the flow of ammonia-rich portal vein blood through a portal-systemic shunt causes a type of encephalopathy known as chronic portal-systemic shunt encephalopathy (CPSE). We herein report two cases of CPSE that presented with opposite changes in the blood ammonia concentrations during hemodialysis. It is curious that the encephalopathy was ameliorated by hemodialysis in case 1, but not case 2. Therefore, it is necessary to recognize CPSE and assess the blood ammonia concentrations in dialysis patients who develop a disturbance of consciousness, even if the serum transaminase level is normal.