Increased default mode network connectivity and increased regional homogeneity in migraineurs without aura

Abstract

Background: The precuneus/posterior cingulate cortex, which has been associated with pain sensitivity, plays a pivotal role in the default mode network. However, information regarding migraine-related alterations in resting-state brain functional connectivity in the default mode network and in local regional spontaneous neuronal activity is not adequate.

Methods: This study used functional magnetic resonance imaging to acquire resting-state scans in 22 migraineurs without aura and in 22 healthy matched controls. Independent component analysis, a data-driven method, was used to calculate the resting-state functional connectivity of the default mode network in the patient and healthy control groups. Regional homogeneity (ReHo) was used to analyse the local features of spontaneous resting-state brain activity in the migraineurs without aura.

Results: Compared with the healthy controls, migraineurs without aura showed increased functional connectivity in the left precuneus/posterior cingulate cortex within the default mode network and significant increase in ReHo values in the bilateral precuneus/posterior cingulate cortex, left pons and trigeminal nerve entry zone. In addition, functional connectivity was decreased between the areas with abnormal ReHo (using the peaks in the precuneus/posterior cingulate cortex) and other brain areas.

Conclusions: The abnormalities in the precuneus/posterior cingulate cortex suggest that migraineurs without aura may exhibit information transfer and multimodal integration dysfunction and that pain sensitivity and pian processing may also be affected.

Keywords: Functional connectivity; Migraine; Precuneus; Regional homogeneity.

Fig. 1

The default mode network (DMN) functional connectivity in migraineurs without aura and healthy controls and the differences between the groups. a DMN network of each group was obtained by one-sample t test (FDR corrected, p = 0.001). The brain areas of the DMN comprised of the medial prefrontal cortex, anterior and posterior cingulate cortexes, precuneus, angular gyrus and cerebellar areas in the migraine and control groups. b Compared with the control group, the migraineurs without aura showed significantly increased intra-network connectivity in the left posterior cingulate and precuneus. c The mean ICA z-scores were extracted from the significantly altered brain area in each subject. No significant differences in intra-network FC were observed between the female and male migraineurs. d The ICA z-score of the precuneus/PCC was positively correlated with the HIT-6 score (r = 0.46, P < 0.05). HC, healthy control; M, migraineurs without aura

Fig. 2

Regional homogeneity (ReHo) maps in migraineurs without aura and healthy controls and the differences between groups. a The ReHo maps of each group were obtained by one-sample t test (FDR corrected, P = 0.001). b When comparing controls, the migraine patients exhibited significantly increased ReHo values in the bilateral precuneus/PCC, pons and trigeminal nerver entery zone. c The mean ReHo z-scores were extracted within the significantly altered brain area of each subject. There were no significant differences in ReHo between the female and male migraineurs without aura. d The ReHo z-score of the trigeminal nerver entery zone was positively correlated with the HIT-6 score (r = 0.43, p < 0.05). HC, healthy control; M, migraineurs without aura