Objective: Based on the current criteria, the diagnosis of "possible" or "probable" variant Creutzfeldt-Jakob disease (vCJD) implies the absence of periodic sharp wave complexes (PSWCs) in the electroencephalogram (EEG). To verify this point, we investigated the development of the EEG changes along the course of the disease in a pateint with vCJD.
Methods: Long-lasting EEG-polygraphic recordings were performed once a month during the last year of illness.
Results: We found the occurrence of a typical EEG periodic pattern in the late clinical stage of the vCJD patient.
Interpretation: In the light of our finding, the diagnostic criteria for vCJD should be amended to include the possibility of a typical periodic EEG in advanced stages of disease in cases with long survival.