Integrated Anatomical and Functional Connectivity Mapping in Episodic Migraine: A Spectral Graph Theory Approach

Migraine disproportionately affects women, yet how menstrual physiology reshapes large-scale brain communication remains unclear. We combined diffusion-weighted imaging (DWI) and resting-state fMRI in female participants (14 patients with episodic migraine without aura; 15 matched healthy controls) to test how direct and indirect anatomical communication paths in the brain can predict brain fucntion. We used a spectral mapping framework that isolates the contribution of communication paths of a specific length and evaluated, how well brain structure predicts brain function within individuals. Analyses of individual path lengths revealed a non-monotonic dissociation: no difference at one-step (direct) paths, but higher mapping accuracy in patients at intermediate polysynaptic scales (four to six steps). At longer scales, contributions attenuated in both groups. Spatial correspondence analyses localized patient-specific effects to default mode network subsystems across multiple atlas. These findings indicate that migraine-related dysfunction reflects altered mesoscale integration along indirect anatomical routes rather than global disconnection, and they provide a general approach to dissect structure-function coupling by communication scale in disease.