The EEG in E200K familial CJD: relation to MRI patterns

The aim of the study was to examine the relationship between EEG abnormalities and the pattern of MRI changes in familial Creutzfeldt–Jakob Disease (fCJD) patients with E200K mutation. As part of a controlled, prospective study, 13 E200K fCJD patients underwent comprehensive evaluations, with EEG and an extensive MRI protocol that included one of the most prion-disease sensitive sequences, diffusion-weighted imaging (DWI). The relationship between EEG abnormalities and the pattern of DWI hyperintensities was examined. EEG demonstrated the classical CJD finding of PSWC (periodic sharp wave complexes) in five patients (38%) while in eight patients (62%) the EEG showed only slow activity. Six patients showed the typical cortical changes on MRI, and in five of them (83%) concordance between the MRI and the EEG was found. Five patients had isolated basal ganglia involvement per MRI, and in two of them (40%) concordance between the MRI and the EEG laterality was found. In the remaining two patients MRI did not show any changes suggesting CJD and EEG showed focal slow activity. The EEG of our E200K fCJD patients appears similar to that of the largest prion disease patient group, sporadic CJD (sCJD). EEG abnormalities in E200K fCJD appear to correlate mainly with cortical pathology, as revealed by DWI, rather than basal ganglia pathology. The observation that PSWC abnormalities reflect cortical rather than basal ganglia pathology is significant with respect to theories of the origins of EEG abnormalities in prion disease.