Papers of the Week

Background Migraine is a common disorder with high social and medical impact. Patients with migraine have a much higher chance of experiencing headache attacks as compared to the general population. Recent neuroimaging studies have confirmed that pathophysiology in the brain is not limited to the moment of the attack but is also present in between attacks, the interictal phase. Methods In this study, we hypothesized that the topology of functional brain networks is also different in the interictal state, compared to people who are not affected by migraine. We also expected that the level of network disturbances scales with the number of years people have suffered from migraine. Functional connectivity between 78 cortical brain regions was estimated for source-level magnetoencephalography (MEG) data by calculating the Phase Lag Index (PLI), in five frequency bands (delta-beta), and compared between healthy controls (n=24), and patients who had been suffering from migraine longer than 6 years (n=12) or shorter than 6 years (n=12). Moreover, the topology of the functional networks was characterized using the Minimum Spanning Tree (MST). Results The migraine groups did not differ from each other in functional connectivity. However, the network topology was different as compared to healthy controls. The results were frequency specific, and higher average nodal betweenness centrality was specifically evident in higher frequency bands in patients with a longer disease duration, while an opposite trend was present for lower frequencies. Conclusion This study shows that patients with migraine have a different network topology in the resting-state as compared to healthy controls, whereby specific brain areas have altered topological roles in a frequency specific manner. Some alterations appear specifically in patients with long-term migraine, which might show the long-term effects of the disease.