The effect of medication on cross frequency coupling in Parkinson’s disease

This Study demonstrates that non-invasive scalp EEG can detect and characterize nested phase-amplitude coupling (PAC) patterns in Parkinson's disease (PD), particularly a delta-driven hierarchy involving delta (0.5–4 Hz), beta (13–30 Hz), and gamma (70–110 Hz) bands, and to evaluate its potential as a biomarker for medication efficacy through modulation of these couplings. Resting-state EEG data from 15 PD patients (on and off dopaminergic medication) and 16 healthy controls were analyzed. Manual preprocessing was applied, including bandpass filtering, independent component analysis for artifact rejection, and visual inspection. Statistical group-level analysis identified significant channels (e.g., F4) via power spectrum features. PAC metrics, using the mean vector length modulation index, were calculated to assess delta-beta and beta-gamma couplings. Unmedicated PD patients exhibited elevated delta-beta and beta-gamma PAC compared to controls, which were significantly attenuated following dopaminergic therapy (p