Supplementary Material for: The Clinical Stages of Sporadic Creutzfeldt-Jakob Disease with Met/Met Genotype in Korean Patients

<b><i>Background:</i></b> Clinical diagnosis of sporadic Creutzfeldt-Jakob disease (sCJD) is currently based on changes occurring in the late disease stages, which limits early-stage detection. Therefore, we investigated the disease course from the vague symptomatic to the terminal phase. <b><i>Methods:</i></b> We retrospectively reviewed 36 sCJD patient records, classifying the disease progression into 4 stages based on clinical manifestations: vague symptomatic, possible CJD, probable CJD and chronic vegetative state. We analyzed findings from diffusion-weighted imaging (DWI), electroencephalography (EEG) and cerebrospinal fluid (CSF) 14-3-3 protein testing performed at each stage. <b><i>Results:</i></b> In stage 1, the most distinctive feature was DWI hyperintensities in the neocortex, even with negative CSF 14-3-3 protein and EEG results. In stage 2, DWI hyperintensities in the limbic cortex were more remarkable. CSF 14-3-3 protein testing yielded positive results in >80% of patients; EEG showed sensitivity in <30% of patients. With progression toward stage 3, DWI hyperintensities in the subcortical nucleus increased, with a sustained higher rate of hyperintensities in the limbic and neocortical regions. With gradual progression to stage 4, the sensitivity of CSF 14-3-3 protein testing and EEG decreased and increased, respectively within limited data. <b><i>Conclusions:</i></b> Understanding disease stage-dependent differences in clinical symptoms and laboratory test results will facilitate early and accurate diagnosis.