Serial EEG findings in sporadic and iatrogenic Creutzfeldt–Jakob disease

Objective: To study temporal and spatial development of EEG patterns in sporadic and iatrogenic Creutzfeldt–Jakob disease patients. Methods: Temporal and spatial development of EEG patterns in 4 patients with sporadic Creutzfeldt–Jakob disease and 2 patients with iatrogenic Creutzfeldt–Jakob disease due to implantation of contaminated brain depth electrodes were investigated. A total of 56 EEGs were analyzed, over time spans ranging from 1272 to 3 days prior to death. Results: Frontal intermittent rhythmical delta activity (FIRDA) was seen at early timepoints in 4/6 patients and might represent an early EEG pattern that is associated, with human prion diseases. EEG patterns associated with CJD are sensitive to midazolam. Initial EEG changes were seen at the site of prion exposure in iatrogenic Creutzfeldt–Jakob disease patients, before they could be observed at distant sites, suggesting that prion disease was initiated at the site of prion exposure. Conclusions: Serial EEG recordings are a valuable tool not only in the early diagnosis of sporadic CJD, but also in the determination of prion exposure in iatrogenic Creutzfeldt–Jakob disease. Significance: FIRDA occur at an early stage of CJD and are progressively replaced by the classical PSWC. The EEG patterns of CJD are sensitive to midazolam. The initial EEG changes in iatrogenic CJD are seen at the site of prion exposure.