Creutzfeldt-Jakob disease with florid-type plaques after cadaveric dura mater grafting

Background: Many reported cases of iatrogenic Creutzfeldt-Jakob disease (CJ D) developed after grafting cadaveric dura mater contaminated with CJD prio ns (dura-associated CJD). They are known to be clinicopathologically simila r to sporadic CJD. We report herein 2 autopsy cases of dura-associated CJD with atypical clinicopathological features. Patients: Two patients presented with progressive ataxia and mental deterio ration 10 or 11 years after neurosurgical treatment with cadaveric dural gr afting, which led to their deaths at 8 and 17 months, respectively, after o nset. Results: The cases were clinically atypical in exhibiting no or late occurr ence of myoclonus and periodic synchronous discharges on electroencephalogr aphic studies. They were pathologically unique in several aspects. The most striking feature was the presence of many prion protein (PrP) plaques in m ultiple areas in the brain. Some of them were the "florid" type surrounded by a zone of spongiform changes known to be a hallmark for the new variant CJD. The distribution of spongiform degeneration was also unique in that it was intense in the thalamus, basal ganglia, and the dentate nuclei of the cerebellum but milder in the cerebrum. There were no mutations in the PrP g ene of the patients. There was no major difference in the size and glycofor m pattern between the abnormal isoform of PrP extracted from the brain tiss ue from the dura-associated cases of CJD and that from a sporadic case of C JD. Conclusions: These 2 cases are clinicopathologically distinct from typical dura-associated cases of CJD. They may be a subtype with florid-type plaque s in dura-associated CJD.