Progressive late delayed postirradiation encephalopathy with Klüver-Bucy syndrome. Serial MRI and clinico-pathological studies.

The first pathologically documented case of progressive late delayed postirradiation encephalopathy in a 37-year-old man with Klüver-Bucy syndrome (KBS) is reported here. The pathological findings and clinical course of KBS with recurrent stroke-like episodes and partial epilepsy within a 7-year period following a 'safe dose' radiation therapy for pituitary tumor are presented. Serial magnetic resonance imaging shows, at different stages of the disease, a pontine infarct, enlarged temporal lobes with serpentine hyperintense signal at cortical gyri on T2-weighted and proton density MRI, and progressive brain calcification which appears hyperintense on T1-weighted images and hypointense on T2-weighted images.