Exploring Subcortical and Cortical Neural Complexity in Migraine: A Fractal and Spectral Analysis Approach

Migraine is a common neurological disorder linked to altered neural processing and sensory integration. For the first time, this study uses Functional Source Separation (FSS) spatial filters estimated on high-density Electroencephalography (EEG) data to examine cortical and subcortical neural dynamics in migraineurs. Twenty-two migraine patients and 25 healthy volunteers underwent EEG recordings, with spectral properties analyzed via Power Spectrum Density (PSD) and signal complexity assessed using Higuchi's Fractal Dimension (HFD). Migraine patients showed increased low-frequency power and fractal complexity in the brainstem and thalamus, indicating subcortical dysfunction. In contrast, no significant cortical alterations were observed except for the alpha band, suggesting that cortical abnormalities may be secondary. These findings highlight the role of subcortical networks in migraine pathophysiology and support their potential as therapeutic targets.