[Portal-systemic encephalopathy with bilateral thalamic and internal capsule lesions using diffusion-weighted MRI in a super-aged patient].

We describe the case of a 90-year-old woman who was hospitalized in July 2016 and subsequently experienced a sudden decline in consciousness level resulting in a state of deep coma. Involuntary movements were not observed, and bilateral Babinski signs were inconclusive. Diffusion-weighted MRI (DWI) of the brain showed bilateral hyperintensity in the thalamus and internal capsule, laboratory testing detected high levels of plasma ammonia, and an electroencephalogram showed delta waves and triphasic waves predominantly in the frontal lobe.