Preventive treatment effects on brain structures and functions in patients with chronic migraine: A multimodel magnetic resonance imaging study

Abstract

Patients with chronic migraine (CM) often exhibit structural and functional alterations in pain-matrix regions, but it remains unclear how preventive treatment affects these changes. Therefore, this study aimed to investigate the structural and functional changes in pain-matrix regions in CM patients after 6-month treatment. A total of 24 patients with CM and 15 healthy controls were recruited for this study. Patients were divided into responder group (N = 9) and non-responder group (N = 15). After completing the Migraine Disability Assessment (MIDAS) questionnaire, all patients underwent whole-brain high-resolution T1-weighted images, diffusion-weighted imaging, and resting-state functional magnetic resonance imaging at baseline and 6-month follow-up. Whole brain gray matter volume and white matter diffusion indices were analyzed using voxel-based analysis. Structural and functional connectivity analyses were performed to understand brain changes in patients after 6-month preventive treatment. The responder group exhibited significantly higher MIDAS scores than the non-responder group at baseline, but no significant difference between the two groups at follow-up. No significant interval change was noted in gray matter volume, white matter diffusion indices, and structural connectivity in CM patients after 6-month treatment. Nonetheless, the functional connectivity was significantly increased between occipital, temporal lobes and cerebellum, and was significantly decreased between parietal and temporal lobes after 6-month preventive treatment. We concluded that resting-state functional connectivity was suitable for investigating the preventive treatment effect on CM patients.

Keywords: functional MRI; functional connectivity; migraine; pain‐matrix network; structural connectivity.

FIGURE 1

Voxel‐based comparison of gray matter volume between the migraines and healthy controls at baseline (A–C) and follow‐up scans (D–F). The significant regions were enlarged for better visualization at baseline (i–iv) and follow‐up (v–viii). In VBM analysis, the gray matter volumes were estimated on a voxel‐by‐voxel basis, and the volumes were compared between the two groups for the whole brain areas. After statistical analysis, those regions (or imaging voxels) with statistical significance were displayed in yellow‐to‐red colors and superimposed on MR images. The red indicates lower T score (lower significance) and yellow indicates higher T score (higher significance). The T value is indicated by the color bar on the right.

FIGURE 2

Significant correlations between gray matter volume and MIDAS scores in the left cerebellum 8 (A), right cerebellum 8 (B), and right postcentral gyrus (C) in patients after 6‐month treatment.

FIGURE 3

The significant increases (red connections) and decreases (blue connections) of functional connectivity between the brain regions in the migraines after 6‐month treatment.

FIGURE 4

The relationships between functional connectivity and MIDAS scores in the connection between left superior parietal lobule (SPL) and right posterior division of the inferior temporal gyrus (pITG).

FIGURE 5

The interval changes of functional connectivity in the responders (A) and non‐responders (B). Asterisks (*) indicate significant difference (p < 0.05).