Redefining periodic patterns on electroencephalograms of patients with sporadic Creutzfeldt-Jakob disease

•We redefined various periodic patterns in the EEG of sCJD using the ACNS criteria.•iPDs+R, RSWs and PDs appeared at different time point during the disease course.•Periodic patterns might be a predictive factor of a rapid progression of sCJD.

ObjectiveWe aimed to redefine various periodic patterns (PPs) observed on electroencephalography (EEG) in patients with sporadic Creutzfeldt-Jakob disease (sCJD) using the American Clinical Neurophysiology Society's (ACNS) Criteria.MethodsWe analyzed EEG data of 23 patients with sCJD were admitted to two university hospitals between August 2005 and September 2015.ResultsWe classified PPs on EEG data into three types: irregular periodic discharges (PDs) with superimposed rhythmic activities, appearing at a median of 8 weeks after onset (w.a.o.); rhythmic sharp-and-wave, at a median of 11 w.a.o.; and PDs with biphasic or triphasic morphology, at a median of 17 w.a.o. Of 16 patients presenting with PPs, 14 had widespread lesions in both cortical and subcortical areas with clinical stage III at admission, and shorter time intervals for admission to hospital from disease onset than patients without PPs (Patients with PP, 11.6 ± 12.2 weeks; without PP, 18.2 ± 8.3 weeks; p = 0.033).ConclusionsPPs largely presented as three types at different stages of disease progression, and patients who had PPs had more wide spread lesions and rapid disease progression.SignificanceOur redefinition of PPs demonstrated on EEG using the ACNS criteria may contribute to further understanding of the pathological mechanisms of sCJD, and PPs might be a predictive factor of a rapid sCJD progression.