Cortical thickness studies in migraine: Current evidence and future directions

BackgroundStructural imaging offers insight into migraine pathogenesis. Magnetic resonance imaging (MRI) morphometry plays a crucial role in identifying these alterations, yet the clinical significance remains debated. While gray matter volume and cortical curvature are commonly analyzed, cortical thickness offers a more direct measure of cytoarchitectural differences and neuroplastic changes in migraine. Advanced structural MRI techniques, including surface-based morphometry and voxel-based morphometry, have provided insights into cortical thickness alterations in migraine. These methods enable high-resolution assessment of brain morphometry, revealing dynamic changes associated with migraine phases and treatment.MethodsThis narrative review synthesizes findings from cortical thickness studies, focusing on methodological approaches, variations in imaging sequences and study designs, including cross-sectional and longitudinal studies.ResultsStudies using surface-based morphometry (i.e. SBM) and voxel-based morphometry (i.e. VBM) have reported inconsistent findings. Increased thickness is frequently observed in pain-processing regions, such as the somatosensory cortex, insula and anterior cingulate cortex reflecting hyperexcitability or maladaptive neuroplasticity. by contrast, cortical thinning has been noted in regions such as the orbitofrontal cortex, posterior cingulate cortex and visual cortex, suggesting neuronal loss or impaired cortical integrity. Differences between episodic and chronic migraine further highlight progressive structural changes associated with disease burden. Emerging evidence also suggests that preventive treatments, including calcitonin gene-related peptide monoclonal antibodies and botulinum toxin A, may reverse some of these cortical alterations, particularly in treatment responders.ConclusionsCortical thickness analysis provides valuable insights into migraine pathophysiology, offering a potential biomarker for disease progression and treatment response. However, inconsistencies across studies highlight the need for standardized MRI protocols and larger longitudinal investigations to clarify the clinical relevance of cortical thickness changes in migraine.