High-density EEG in the eyes closed condition reveals early reduction of alpha oscillations after galcanezumab: A pilot study in migraine

Objective: This study investigates the impact of galcanezumab on spontaneous cortical electrical activity, focusing on its potential to reduce abnormal alpha oscillations. Methods: We recorded high-density spontaneous EEG (hd-EEG) in 10 migraine patients before (T0) and 7 days after the first galcanezumab administration (T1) in eyes open (EO) and closed (EC) conditions. For each EEG frequency band, we assessed total power, including both aperiodic and periodic components, of the Power Spectral Density (PSD), and compared values between T0 and T1. For the alpha band, we further estimated the change in the periodic component. Clinical changes were assessed through MIDAS and MMD scores after 3 months (T2). Results: All patients showed clinical improvement. At the electrophysiological level, alpha total power (FDR corrected P = 0.034) and alpha periodic power (P = 0.005) significantly decreased in T1 in EC condition. No significant changes were observed in EO, nor in other frequency bands. Conclusions: Alpha power, previously found to be elevated in migraine, decreased after galcanezumab treatment in EC condition. Significance: These findings point to a cortical effect of galcanezumab in migraine patients as early as 7 days after treatment. The EC condition appears particularly sensitive and should be included in future evaluations.