Specific early electroencephalogram for the diagnosis of sporadic Creutzfeldt-Jakob disease.

An early diagnosis is required for intervention in prion disease cases. To elucidate the specificity of early electroencephalography discharges in cases of sporadic Creutzfeldt-Jakob disease, we analysed epileptiform discharges through electroencephalography. Nine patients with methionine/methionine type 1/classic sporadic Creutzfeldt-Jakob disease and 20 patients with status epilepticus were included. Generalized periodic discharges, lateralized periodic discharges, and central sagittal sporadic epileptiform discharges were evaluated. Central sagittal sporadic epileptiform discharges were defined as nonrhythmic and nonperiodic waveforms showing generalized spike-and-wave complexes and/or sharp waves predominantly in the central sagittal region. In the sporadic Creutzfeldt-Jakob disease group, central sagittal sporadic epileptiform discharges, lateralized periodic discharges, and generalized periodic discharges were observed in five (55.6%), one (11.1%), and eight (88.9%) patients, respectively, with an average duration from onset to the appearance of the discharges of 1.6, 1.0, and 2.44 months, respectively. In the status epilepticus group, these discharges were detected in one (5.0%), six (30.0%), and six (30.0%) patients, respectively. The incorporation of central sagittal sporadic epileptiform discharges and lateralized periodic discharges into the World Health Organization diagnostic criteria, alongside generalized periodic discharges, significantly shortened the average lapse from symptom onset to sporadic Creutzfeldt-Jakob disease diagnosis (2.06 months vs. 2.44 months; p = 0.02). Central sagittal sporadic epileptiform discharges emerge as promising biomarkers for distinguishing sporadic Creutzfeldt-Jakob disease from status epilepticus, and together with lateralized periodic discharges provide an opportunity for early diagnosis of sporadic Creutzfeldt-Jakob disease.