Portal-systemic shunt encephalopathy presenting with diffuse cerebral white matter lesion: an autopsy case.

We report herein an autopsy case of portal-systemic encephalopathy (PSE) presenting with diffuse tissue rarefaction in the cerebral deep white matter. Clinically, the patient showed recurrent episodes of unconsciousness, abnormal behavior and urinary incontinence, as well as flapping tremor. Cognitive impairment and peripheral neuropathy developed following recurrent episodes. Although conventional arterial portography revealed a small portal-systemic collateral vessel of a left gastro-renal venous shunt, abdominal CT and liver biopsy showed no evidence of liver cirrhosis and serum ammonia level showed a mild increase. T2-weighted MRI demonstrated symmetrical signal hyperintensities in the deep white matter. Neuropathological findings showed Alzheimer type II astrocytes in the deep layers of the cerebral cortices and severe tissue rarefaction with no or slight reactive astrocytosis in the subcortical and deep white matter. These white matter changes have been reported infrequently in patients with PSE. The present case suggests that chronic PSE without liver cirrhosis may develop diffuse white matter lesions.