CLINICAL CHANGES AND EEG PATTERNS PRECEDING THE ONSET OF PERIODIC SHARP WAVE COMPLEXES IN CREUTZFELDT-JAKOB-DISEASE

The conversion of EEG findings and the evolution of clinical signs was investigated in 7 CJD patients who underwent serial EEG recordings al ong the course. At the onset of PSWC (mean 8.7 weeks:), 5 :patients ha d already progressed to akinetic mutism (characterized by loss of verb al contact and directed responses); and a CJD-typical-movement disorde r (myoclonia, exaggerated startle reaction or focal dyskinesia) had st arted in 5 patients. When akinetic mutism commenced (on average at 7.5 weeks), runs of frontal intermittent non-peaked rhythmical delta acti vity (FIRDA) were found in all cases. These were later replaced by PSW C in 6 patients (interval 1 to 3 weeks). Occurrence of PSWC was often negatively related to external stimuli (2 of 6 cases), and sedative me dication (all patients tested). We conclude that the selection of EEG recording dates to detect PSWC in CJD-candidates should be guided by d etailed information about movement disorders and conscious level. Rega rding the short survival time after their onset (average 8 weeks), PSW C usually mark the terminal stage of CJD. To detect PSWC, especially, EEG registrations in advanced stages are often necessary. In earlier d isease stages, FIRDA-like EEG activities should be regarded as compati ble with this diagnosis, and encourage further EEG studies for the dem onstration of PSWC in a more advanced stage of CJD.