Brain imaging in migraine with and without aura: Similarities and differences.

BackgroundWhether migraine with aura (MA) is a biologically independent entity from migraine without aura (MO) is still debated. Similarities and differences between MO and MA have been extensively investigated in recent years through several neuroimaging studies, providing valuable insights into their underlying pathophysiology. To provide a better understanding of functional and structural differences between MO and MA, we conducted a narrative review of neuroimaging studies in these two conditions.MethodsA comprehensive PubMed search for neuroimaging studies in MO and MA was conducted in May 2025. We included studies that directly compared the two conditions using diffusion tensor imaging, voxel-based morphometry, surface-based morphometry, functional MRI and arterial spin labeling studies. No publication date restrictions were applied.ResultsOverall, patients with MA exhibited heightened engagement of the visual regions, cerebellum and thalamus. However, both MO and MA shared common activation of parts of the salience network and involvement of similar visual areas, including the striate and extrastriate cortices. However, contrasting results and several inconsistencies emerged from the analysis of different imaging studies. These included the lack of specification regarding the phase of the migraine cycle during which the scans were conducted, the inclusion of patients under migraine prevention, small sample sizes, and different approaches to data and statistical analysis (including a more liberal approach to interpreting results).ConclusionsAlthough several biases influence the reliability of most findings, patients with MA exhibited higher involvement of visual processing regions, decreased cerebellar antinociceptive activity and impaired thalamic information filtering. Whether this pattern represents the consequence of the recurrence of cortical spreading depression or a primary predisposition to it remains to be determined. Future studies with a rigorous and standardized approach are needed to understand the differences between MO and MA.