Interictal quantitative EEG in migraine: a blinded controlled study

Abstract

Abnormal electroencephalography (EEG) in migraineurs has been reported in several studies. However, few have evaluated EEG findings in migraineurs during a time period when neither the last attack nor the next attack may interact with the results. We, therefore, compared interictal EEG in migraineurs and headache-free subjects with a design controlled for interference by pre-ictal changes. Pre-ictal EEG findings in the painful cranial side during the next attack after registration were also investigated. Correlations between clinical variables and EEG are reported as well. Interictal EEGs from 33 migraineurs (6 with and 27 without aura) and 31 controls were compared. Absolute power, asymmetry and relative power were studied for delta, theta and alpha frequency bands in parieto-occipital, temporal and fronto-central areas. EEG variables were correlated to attack frequency, headache duration, attack duration, pain intensity, photo- and phonophobia. Compared with controls, migraineurs had increased relative theta power in all cortical regions and increased delta activity in the painful fronto-central region. Absolute power and asymmetry were similar among groups. In age-adjusted analyses, headache intensity correlated with increased delta activity. In this blinded controlled study, we found globally increased relative theta activity in migraineurs. A slight interictal brain dysfunction is probably present between attacks.

Resting-state EEG power and coherence vary between migraine phases

“…Furthermore, in the pre-ictal phase (before migraine attacks), migraine patients exhibit normal habituation of visually-evoked and auditory-evoked potentials [13], but decreased motor cortex activity [14]. However, resting-state cortical activities, such as EEG power density and effective connectivity, have not been studied much in relation to particular migraine phases [15, 16]. …”

“…Compared to stimulation-related tasks, resting-state experiments, in which additional cortical activations are not induced, are more convenient and comfortable for migraine patients. Previous resting-state studies have shown dynamic EEG power changes in migraine patients [15, 16, 18]. EEG coherence, which involves cross-correlation between signals in the frequency domain to reveal interrelationships of EEG signals, is a widely used measure of functional connectivity [19].…”

From migraine to epilepsy: a threshold mechanism?

“…These slow activity should increase even more just before the headache attack in the same patients. Bjørk and co-workers [11] found that delta activity was increased even before pain onset on the affected side in migraineurs. Furthermore, alpha rhythm changes were observed along the migraine cycle, correlated with increasing disease and attack duration [12].…”

Quantitative electroencephalography analysis in university students with hazardous alcohol consumption, but not alcohol dependence

“…1). Values for either AP, RP, or MF from all the electrodes within one region were averaged as reported elsewhere [17][18][19]. FZ was not included in statistical analysis to allow the inclusion of the same number of electrodes in each region to achieve a more reliable comparison between regions.…”