Disrupted default mode network connectivity in migraine without aura

Abstract

Background: Resting-state functional magnetic resonance imaging (RS-fMRI) has demonstrated disrupted default mode network (DMN) connectivity in a number of pain conditions, including migraine. However, the significance of altered resting-state brain functional connectivity in migraine is still unknown. The present study is aimed to explore DMN functional connectivity in patients with migraine without aura (MwoA) and investigate its clinical significance.

Methods: To calculate and compare the resting-state functional connectivity of the DMN in 20 patients with MwoA, during the interictal period, and 20 gender- and age-matched HC, Brain Voyager QX was used. Voxel-based morphometry was used to assess whether between-group differences in DMN functional connectivity were related to structural differences. Secondary analyses explored associations between DMN functional connectivity, clinical and neuropsychological features of migraineurs.

Results: In comparison to HC, patients with MwoA showed decreased connectivity in prefrontal and temporal regions of the DMN. Functional abnormalities were unrelated to detectable structural abnormalities or clinical and neuropsychological features of migraineurs.

Conclusions: Our study provides further evidence of disrupted DMN connectivity in patients with MwoA. We hypothesize that a DMN dysfunction may be related to behavioural processes such as a maladaptive response to stress which seems to characterize patients with migraine.

Figure 1

Group level DMN connectivity in HC (A) and patients with MwoA (B) (p < 0.05, cluster-level corrected) HC: healthy controls; MwoA: migraine without aura.

Figure 2

Statistically significant differences within the DMN between patients with MwoA and HC groups. A) T-map of statistically significant differences within the DMN between patients with MwoA and HC groups (p < 0.05, cluster-level corrected) overlaid on the standard “Colin-27” brain T1 template. Talairach coordinates (x,y,z): top: right l-SPFG = −13, 43, 42; bottom: right l-TP = −34, 10, -14. B) Bar graphs of the ROI-averaged ICA z-scores (±SD) for patients with MwoA and HC groups. Top: l-SPFG (MwoA patients: 0.15 ± 0.63; HC: 2.12 ± 0.43; p = 0.01). Bottom: l-TP (MwoA patients: -0.09 ± 0.55; HC: 0.72 ± 0.29; p = 0.003). DMN: default mode network, MwoA: migraine without aura, HC: healthy controls, ICA: independent component analysis, l-SPFG: left superior prefrontal gyrus; l-TP: left temporal pole.