Brain networking analysis in migraine with and without aura

Marina De Tommaso,R Siugzdaite,Eleonora Vecchio,Katia Ricci,Gabriele Trotta,Sebastiano Stramaglia

doi:10.1186/s10194-017-0803-5

Abstract

BackgroundTo apply effective connectivity by means of nonlinear Granger Causality (GC) and brain networking analysis to basal EEG and under visual stimulation by checkerboard gratings with 0.5 and 2.0 cpd as spatial frequency in migraine with aura (MA) and without aura (MO), and to compare these findings with Blood Oxygen Level Dependent (BOLD) signal changes.MethodsNineteen asymptomatic MA and MO patients and 11 age and sex matched controls (C) were recorded by 65 EEG channels. The same visual stimulation was employed to evaluate BOLD signal changes in a subgroup of MA and MO. The GC and brain networking were applied to EEG signals.ResultsA different pattern of reduced vs increased GC respectively in MO and MA patients, emerged in resting state. During visual stimulation, both MA and MO showed increased information transfer toward the fronto-central regions, while MA patients showed a segregated cluster of connections in the posterior regions, and an increased bold signal in the visual cortex, more evident at 2 cpd spatial frequency.ConclusionsThe wealth of information exchange in the parietal-occipital regions indicates a peculiar excitability of the visual cortex, a pivotal condition for the manifestation of typical aura symptoms.

Highlights

To apply effective connectivity by means of nonlinear Granger Causality (GC) and brain networking analysis to basal EEG and under visual stimulation by checkerboard gratings with 0.5 and 2.0 cpd as spatial frequency in migraine with aura (MA) and without aura (MO), and to compare these findings with Blood Oxygen Level Dependent (BOLD) signal changes
Granger causality In this study we evaluated effective connectivity by means of Granger Causality (GC) and Transfer Entropy (TE), using the nonlinear generalization of GC, by Kernel methods, presented in our previous study [14, 15, 21], which allows to infer the directional information flow in nonlinear and multivariate systems [22, 23]
Patients showed reduced functional connections in the temporal-parietal posterior regions in all bands, and in frontal regions in theta band, while this pattern was absent in MA patients (Fig. 1) In beta band MA patients showed increased information transfer compared to controls and MO patients (Fig. 1) in both input and output direction. (Fig. 1)

Summary

Introduction

To apply effective connectivity by means of nonlinear Granger Causality (GC) and brain networking analysis to basal EEG and under visual stimulation by checkerboard gratings with 0.5 and 2.0 cpd as spatial frequency in migraine with aura (MA) and without aura (MO), and to compare these findings with Blood Oxygen Level Dependent (BOLD) signal changes. The study of ongoing EEG activity in basal condition and during sensory stimulation, may clarify how the migraine brain has a different reactivity, expressed by the changes of the main rhythms.under different types of stimulation. This brain behavior may predispose to the cascade of the events occurring during migraine attack, including cortical spreading depression and trigeminal-vascular system activation. The phase synchronization of posterior dominant alpha rhythm (8-12.5 Hz) was lower during intermittent photic stimulation than in basal condition in healthy subjects

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