This cross-sectional study included 24 drug-naive CSF-proven EOAD patients and age-, sex, and education-matched healthy controls. All participants underwent a detailed neuropsychological evaluation, resting-state electroencephalography (EEG) recording, and Magnetic Resonance Imaging (MRI). Gamma power and coherence were measured in total gamma (30-48 Hz), gamma-1 (30-35 Hz), gamma-2 (35-40 Hz), and gamma-3 (40-48 Hz) frequency bands. Gray matter volumes were extracted for 54 regions of interest (ROIs) and compared between groups. Discriminant analysis was performed to determine the classification accuracy of gamma activity for EOAD. Finally, correlations between CSF, neuropsychological tests, EEG, and MRI measures were explored.