[A case of portal-systemic encephalopathy presenting characteristic MR images in globus pallidus, hypothalamus, corpus callosum, pontine base, and middle cerebellar peduncle].

A 53-year-old woman developed symptoms of slow speech, mild dementia, increased deep tendon reflex, ataxic gait, flapping tremor, and dystonic posture during two years. She had liver cirrhosis and hyperammonemia, which suggested a diagnosis of portal-systemic encephalopathy. MR T1-weighted images showed increased signal intensity in globus pallidus, internal capsule, substantia innominata, and a part of hypothalamus. T2-weighted images revealed abnormal findings as follows: high intense area in middle cerebellar peduncle, and low signal intensity of corpus callosum and pontine base. This is the first report about MRI abnormalities in substantia innominata, corpus callosum, and pontine base in a patient with portal-systemic encephalopathy.