The link between higher cortical dysfunctions during migraine aura and volume of the hippocampus

Abstract

Objective: The role of the hippocampus is insufficiently explored in migraine with aura (MwA). Moreover, the heterogeneity of MwA patients prevents studies to investigate particular roles of specific brain regions in MwA pathophysiology. This study aimed to compare subgroups of MwA patients and healthy controls (HCs) regarding the volume of the hippocampus. Methods: MwA patients were assigned to the MwA-HCD group if they reported higher cortical dysfunctions (HCDs) during the aura or to the MwA-non-HCD group if they did not experience HCDs. Both subgroups were compared in between and to HCs to evaluate any specific changes in the hippocampus. Neuroimaging data derived from FreeSurfer‐based segmentation of hippocampal subfields acquired from a 3 T magnetic resonance machine was used for comparisons. Results: A total of 46 MwA patients (28 MwA-HCD group and 18 MwA-non-HCD group) and 31 HCs were studied. There were no significant differences in age and sex between groups (p=0.490 and p=0.934, respectively). The MwA-HCD group had significantly smaller volumes of the left (3328 vs. 3677 mm3, p<0.001) and right (3395 vs. 3748 mm3, p<0.001) hippocampus compared to the MwA-non-HCD group. Also, the MwA-HCD group had significantly smaller volumes of the left (3328 vs. 3541 mm3, p=0.002) and right (3395 vs. 3592 mm3, p=0.015) hippocampus compared to HCs. There was no significant difference between the MwA-non-HCD group and HCs relative to the hippocampal volumes. Conclusion:Smaller volumes of the left and right hippocampus might play an important role in the pathophysiology of HCDs during MwA attacks. Further functional neuroimaging studies are needed to explain the results of this study.