Brain structural and functional differences between pure menstrual migraine and menstrually-related migraine.

The pathophysiological differences between menstrually-related migraine (MRM) and pure menstrual migraine (PMM) are largely unclear. The aim of this study was to investigate the potential differences in brain structure and function between PMM and MRM. Forty-eight menstrual migraine patients (32 MRM; 16 PMM) were recruited for this study. Voxel-based morphometry (VBM) was applied on structural magnetic resonance imaging (sMRI), and the amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo) in resting state functional MRI (rsfMRI) were calculated. No significant between-group difference was observed in the grey matter volume (GMV). MRM patients exhibited lower ALFF values at the dorsolateral prefrontal cortex (DLPFC) and medial prefrontal cortex (mPFC) than PMM patients. Moreover, the MRM group showed significantly higher ReHo values in the DLPFC. Higher values in the mPFC were related to higher expression of calcitonin gene-associated peptide (CGRP) in the PMM group (r = 0.5, P = 0.048). Combined ALFF and ReHo analyses revealed significantly different spontaneous neural activity in the DLPFC and mPFC, between MRM and PMM patients, and ALFF values in the mPFC were positively correlated with CGRP expression, in the PMM group. This study enhances our understanding of the relationship between neural abnormalities and CGRP expression in individuals with PMM.