Case report: An unusual case of portal systemic encephalopathy

Hemodialysis-related portal-systemic encephalopathy: A rare cause of recurrent encephalopathy among patients on maintenance hemodialysis

Portal-systemic venous shunts can rarely develop without any intrinsic liver diseases. However, the cause of shunt formation in these cases are not very clear. Literature suggests that hemodialysis can precipitate symptoms in patients with asymptomatic portal-systemic venous shunts (PSVS). Rare presentations of recurrent encephalopathy due to PSVS in the absence of liver dysfunction has been described in patients undergoing hemodialysis. We report a rare case of recurrent Hemodialysis Related Porto-Systemic Encephalopathy (HRPSE) in a 50-year old male during maintenance hemodialysis secondary to a PSVS between the portal vein and left renal vein. Shunt embolism by an 18 mm Amplatzer vascular plug (AVR II) was done and follow up CT showed complete occlusion of collaterals. Post-procedure, he is undergoing thrice-weekly Hemodialysis of 4 hours duration till date with no further incidence of encephalopathy. Our report indicates that recurrent encephalopathy can occur in dialysis patients due to symptomatic PSVS and HRPSE should be considered even in non-cirrhotic cases for early detection and effective management.

Recurring encephalopathy abolished by gastrorenal shunt ligation in a diabetic hemodialysis patient

A 57-year-old man was admitted to our hospital for hepatic encephalopathy. He previously had undergone a partial gastrectomy for gastric ulcer, and also had been on maintenance hemodialysis because of diabetic nephropathy. Despite treatment with branched-chain amino acids and lactulose, encephalopathy occurred repeatedly. The findings of his laboratory examinations, computed tomography, and liver biopsy were not suggestive of chronic liver damage. Angiography revealed a portal-systemic shunt from the superior mesenteric vein via the left gastric vein to the left renal vein. A ligation of the gastrorenal shunt was performed. After the shunt ligation, hepatic encephalopathy no longer recurred, and no medication was required to prevent it. The insulin requirements also decreased, the plasma ammonia concentration then decreased, and serum concentration of several amino acids related to the ammonia metabolism also decreased. The molar ratio of branched-chain amino acids to aromatic amino acids increased. The ligation of the portal-systemic shunt was thus considered to be the key to the successful treatment of hepatic encephalopathy in this unusual case.

An autopsy case of coexisting portal systemic encephalopathy and senile dementia of the Alzheimer type

An autopsy case of portal systemic encephalopathy and senile dementia of the Alzheimer type coexisting in a 77-year-old man is described. The patient had suffered recurrent episodes of delirium after a subtotal gastrectomy for gastric carcinoma. He died of DIC 45 months after the gastrectomy. A pathological examination revealed a vascular plexus around the liver which might have served as collateral circulation. Neuropathologically, spongy necrosis and Alzheimer type II changes of astrocytes were found in the basal ganglia and fronto-occipital cortices. In the same anatomical regions, only immunohistological staining using antibody against amyloid beta-protein and the periodic-acid methenamine silver method revealed abundant neuriticplaques, cerebral amyloid angiopathy and diffuse plaques. We discussed the clinicopathological findings in this case.

Hepatic Encephalopathy

Hepatic encephalopathy occurs in a number of different species as a result of either congenital portacaval shunts or acquired liver disease. Despite intensive research, the neurochemical basis of the disorder has not been defined. Theories to explain the cerebral dysfunction that accompanies acute or chronic hepatic failure include 1) ammonia acting as the putative neurotoxin, 2) perturbed monoamine neurotransmission as a result of altered plasma amino acid metabolism, 3) an imbalance between excitatory amino acid neurotransmission, mediated by glutamate, and inhibitory amino acid neurotransmission, mediated by gamma-aminobutyric acid, and 4) increased cerebral concentrations of an endogenous benzodiazepine-like substance.