Patients Who Have Aura With Migraine Have Smaller Brain Structures Than Healthy Subjects

A recent study sought to identify possible differences in subcortical structures between patients who have migraine with aura (MwA) and healthy subjects, and also to determine the correlations between the characteristics of migraine aura and the volumes of subcortical structures.

Various features of the cerebral cortex and white matter have been extensively investigated in MwA, but the morphological characteristics of subcortical structures have been largely neglected.

Aura in migraine affects about 20% to 30% of patients; it is a phenomenon whose manifestations coincide with a wave of cortical spreading depolarization/depression (CSD) through the cerebral cortex and/or through the 3 different types of white matter nerve fibers (associative, commissural, and projective). Imaging studies have described multiple changes in the migraineur brain.

A few studies have investigated the role of subcortical structures in the pathophysiology of migraine, revealing decreased volumes of the left caudate, putamen, right nucleus accumbens, and striatum; in addition, it was found that the basal ganglia play a significant role in the pathophysiology of pain in episodic migraine.

However, previous studies did not examine the role of subcortical structures in the pathophysiology of MwA, nor did they look at the volume and shape abnormalities in distinct subcortical structures. Therefore, the aim of this study was to compare the volumes of subcortical structures between patients with MwA and healthy subjects, using advanced structural neuroimaging techniques, as well as the correlations between the characteristics of MwA and the volumes of subcortical structures.

Thirty-two patients with MwA were matched by age and sex to 32 healthy subjects. Regional subcortical brain volumes were automatically calculated using the FSL/FMRIB Image Registration and Segmentation Tool software. A general linear model analysis was used to investigate differences in the volume of subcortical structures between the 2 groups. A partial correlation test was used to assess correlations between the volume of subcortical structures and characteristics of patients with MwA.

The volumes of the right globus pallidus, left globus pallidus, and left putamen were significantly smaller in the brains of patients with MwA than in those without: mean (SD): 1427 (135) mm³ versus 1557 (136) mm³ (P <.001); 1436 (126) mm³ versus 1550 (139) mm³ (P = .001); and 4235 (437) mm³ versus 4522 (412) mm³ (P = .006); respectively. There were no significant relationships between subcortical structures and clinical parameters.

These findings suggest that both the globus pallidi and left putamen play significant roles in the pathophysiology of the MwA. Future studies should determine the cause-and-effect relationships, since these could not be found in this study due to its cross-sectional design.

Reference

Petrusic I, Dakovic M, Zidverc-Trajkovic J. Subcortical volume changes in migraine with aura [published online Jul 15, 2019]. J Clin Neurol. doi: 10.3988/jcn.2019.15.4.448.