Abnormalities in cortical pattern of coherence in migraine detected using ultra high-density EEG

Abstract

Individuals with migraine generally experience photophobia and/or phonophobia during and between migraine attacks. Many different mechanisms have been postulated to explain these migraine phenomena including abnormal patterns of connectivity across the cortex. The results, however, remain contradictory and there is no clear consensus on the nature of the cortical abnormalities in migraine. Here, we uncover alterations in cortical patterns of coherence (connectivity) in interictal migraineurs during the presentation of visual and auditory stimuli, and during rest. We used a high-density EEG system, with 128 customized electrode locations, to compare inter- and intra-hemispheric coherence in the interictal period from 17 individuals with migraine (12 female) and 18 age- and gender-matched healthy control subjects. During presentations of visual (vertical grating pattern) and auditory (modulated tone) stimulation which varied in temporal frequency (4 and 6 Hz), and during rest, participants performed a color detection task at fixation. Analyses included characterizing the inter- and intra-hemisphere coherence between the scalp EEG channels over 2-second time intervals and over different frequency bands at different spatial distances and spatial clusters. Pearson’s correlation coefficients were estimated at zero-lag. Repeated measures analyses-of-variance revealed that, relative to controls, migraineurs exhibited significantly (i) faster color detection performance, and (ii) lower spatial coherence of alpha-band activity, for both inter- and intra-hemisphere connections, and (iii) the reduced coherence occurred predominantly in frontal clusters during both sensory conditions, regardless of the stimulation frequency, as well as during the resting-state. The abnormal patterns of EEG coherence in interictal migraineurs during visual and auditory stimuli, as well as at rest (eyes open), may be associated with the cortical hyper-responsivity that is characteristic of abnormal sensory processing in migraineurs.

Application of EEG in migraine

“…Visual evoked potentials from 20 healthy controls and 70 migraine patients were analyzed in the frequency domain, and the author found that compared to healthy controls, interictal migraine patients had increased visually induced low frequency activity (Lisicki et al, 2020). The research of Gomez-Pilar et al also confirmed our consideration and supports another fact that characteristic neural dynamics in migraine are linked to specific frequency bands but are not necessarily equal to conventional ones (Chamanzar et al, 2021).…”

“…In both sensory stimulation conditions as well as in the resting state, the decrease in consistency occurred predominantly in the frontal lobes, regardless of stimulation frequency. The abnormal pattern considering their EEG coherence may be associated with the cortical hyperreactivity of abnormal sensory processing in migraine patients (Chamanzar et al, 2021).…”

“…The relationship between various frequency bands and clinical characteristics of migraine is also explored in the studies (Bjork et al, 2009a(Bjork et al, ,b, 2011b. The differences in specific frequency bands in migraineurs may depend on where on the scalp the abnormalities appear, in which phases of migraine the EEG signals were recorded and whether the responses were recorded at rest or were stimulus-evoked (Chamanzar et al, 2021). Although with heterogeneous results, most found differences are related to lower-frequency responses.…”

Attenuated alpha oscillation and hyperresponsiveness reveals impaired perceptual learning in migraineurs

“…For example, one study observed migraine patients to have increased theta, delta [ 28 ] and alpha [ 29 ] resting-state activity interictally while in another study, they appeared to show reduced resting theta, alpha, beta power [ 30 ]. Recently, the spatial coherence (functional connectivity) of different frequency bands on migraine patients was also explored [ 31 ]. In addition to resting state, sensory evoked alpha rhythm of migraine sufferers had a lower coherence compared to headache-free controls.…”

Individual finger movement decoding using a novel ultra-high-density electroencephalography-based brain-computer interface system

“…Several studies have demonstrated that narrowing down the inter-electrode distance under 2 cm–commonly and widely used inter-electrode distance–is beneficial since it provides additional neural information ( Freeman et al, 2003 ; Odabaee et al, 2013 ; Petrov et al, 2014 ; Robinson et al, 2017 ). For this reason, some recent studies explored denser electrode layouts in visual and auditory contexts ( Robinson et al, 2017 ; Chamanzar et al, 2021 ; Narayanan et al, 2021 ). Here, we define a novel array formatted dense electrode layout (see small black circles in Figure 1A ) as ultra-high-density EEG (uHD EEG).…”