A preliminary study on brain functional magnetic resonance imaging in migraine patients with visual aura using visual...

Migraine is characterized by high prevalence, recurrent attacks, and poor response to pharmacological interventions, which can severely impair patients' quality of life. The complex and diverse aura symptoms in its clinical presentation further increase the risk of misdiagnosis and mismanagement. Moreover, the pathogenesis of this disorder remains incompletely understood. This study employed a visual stimulation paradigm combined with blood oxygenation level-dependent functional magnetic resonance imaging (BOLD-fMRI) to simultaneously monitor brain functional activity and neuronal dynamics in patients with visual aura migraine (VaM) and migraine without aura (MwoA). The aim was to identify specific brain network features associated with visual aura in VaM, thereby providing new insights into its pathological mechanisms and early differential diagnosis.

From May 2023 to May 2024, 21 patients meeting the diagnostic criteria for VaM and excluding related ocular fundus and optic nerve pathologies during the interictal period (VaM group), 21 patients meeting the criteria for MwoA during the interictal period (MwoA group), and 21 gender- and age-matched healthy controls (HC group) were recruited from the Department of Neurology, Affiliated Hospital of North Sichuan Medical College. All participants underwent visual stimulation using an 8 Hz flickering checkerboard paradigm concurrent with task-state fMRI scanning and image acquisition. The primary outcome was the comparison of brain activation differences among the three groups and between each pair of groups using one-way analysis of variance (ANOVA) and post-hoc multiple comparison analyses. Secondary outcomes included within-group brain activation analysis for the VaM, MwoA, and HC groups using one-sample t-tests.

Brain regions showing differential activation among the VaM, MwoA, and HC groups included: right cerebellar lobule IX, left middle temporal gyrus, left orbital part of the inferior frontal gyrus, left triangular part of the inferior frontal gyrus, left opercular part of the inferior frontal gyrus, left temporal pole: superior temporal gyrus, left medial superior frontal gyrus, left anterior cingulate gyrus, left middle cingulate gyrus, right middle cingulate gyrus, right middle occipital gyrus, left middle occipital gyrus, left superior occipital gyrus, left middle temporal gyrus, right angular gyrus, left precuneus, right precuneus, and left cuneus (p < 0.05). Pairwise comparisons revealed: Compared to the HC group, the VaM group exhibited stronger activation in the left precuneus (p < 0.005). Compared to the HC group, the MwoA group showed stronger activation in the right middle occipital gyrus (p < 0.005) and left middle occipital gyrus (p < 0.05). Compared to the MwoA group, the VaM group demonstrated stronger activation in the right angular gyrus (p < 0.05), left cuneus (p < 0.0001), right middle cingulate gyrus (p < 0.05), and left precuneus (p < 0.05). Conversely, the VaM group showed weaker activation than the MwoA group in the right middle occipital gyrus (p < 0.05).

The results indicate abnormalities in visual-related brain networks in both patient groups, suggesting a central mechanism underlying visual aura generation in VaM. Abnormal activation in regions such as the cuneus, precuneus, and superior occipital gyrus may serve as preliminary indicators that warrant further investigation into visual aura mechanisms, while changes in the middle cingulate gyrus and angular gyrus may be associated with cognitive-emotional aspects of migraine, although this remains exploratory.