“…The characterizations of EEG signals include: EEG frequency spectrum characteristics, evoked potentials and cortical-muscle coherence (CMC). The remaining 11 papers (37%) used resting state EEG to investigate possible biomarkers for cognitive decline in PD patients (Schlede et al, 2011 ; Caviness et al, 2015 , 2016 ; Latreille et al, 2015 ; Cozac et al, 2016 ; Utianski et al, 2016 ; Arnaldi et al, 2017 ), evaluate therapeutic effects (Galvez et al, 2018 ; Babiloni et al, 2019 ), and distinguish PDD patients from other dementia patients, such as AD and DLB (Babiloni et al, 2011 ; Bliwise et al, 2014 ). The EEG frequency spectrum characteristics (the spectral power and/or power density), the event-related desynchronization/synchronization (ERD/ERS), and the EEG connectivity were studied in rest state EEG while sleep EEG, microstate analysis and the grand total EEG (GTE) score were also investigated in PD patients.…”