MAPT and Alzheimer disease: Here, we performed combined simultaneous FO-scalp EEG with polysomnography (PSG) and acquired 18F-MK6240 tau PET-MR in five patients with AD from our initial study cohort45 with subclinical epileptiform activity (SEA) on scalp EEG or a seizure history to investigate the interaction between sleep, neuronal hyperexcitability and tau pathology.