P3 latency as a biomarker for the complexity of migraine with aura: Event-related potential study

Signatures of migraine aura in high-density-EEG

OBJECTIVE

Cortical spreading depolarization is highly conserved among the species. It is easily detectable in direct cortical surface recordings and has been recorded in the cortex of humans with severe neurological disease. It is considered the pathophysiological correlate of human migraine aura, but direct electrophysiological evidence is still missing. As signatures of cortical spreading depolarization have been recognized in scalp EEG, we investigated typical spontaneous migraine aura, using full band high-density EEG (HD-EEG).

METHODS

In this prospective study, patients with migraine with aura were investigated during spontaneous migraine aura and interictally. Time compressed HD-EEG were analyzed for the presence of cortical spreading depolarization characterized by (a) slow potential changes below 0.05 Hz, (b) suppression of faster activity from 0.5 Hz - 45 Hz (c) spreading of these changes to neighboring regions during the aura phase. Further, topographical changes in alpha-power spectral density (8-14 Hz) during aura were analyzed.

RESULTS

In total, 26 HD-EEGs were recorded in patients with migraine with aura, thereof 10 HD-EEGs during aura. Eight HD-EEGs were recorded in the same subject. During aura, no slow potentials were recorded, but alpha-power was significantly decreased in parieto-occipito-temporal location on the hemisphere contralateral to visual aura, lasting into the headache phase. Interictal alpha-power in patients with migraine with aura did not differ significantly from age- and sex-matched healthy controls.

CONCLUSIONS

Unequivocal signatures of spreading depolarization were not recorded with EEG on the intact scalp in migraine. The decrease in alpha-power contralateral to predominant visual symptoms is consistent with focal depression of spontaneous brain activity as a consequence of cortical spreading depolarization but is not specific thereof.

SIGNIFICANCE

Cortical spreading depolarization is relevant in migraine, other paroxysmal neurological disorders and neurointensive care.

Role of sensory processing sensitivity and high sensation seeking in migraine with typical aura

The psychological differences between migraine with aura (MwA) patients and healthy controls (HCs) have not been sufficiently investigated in the current scientific literature. Taking this into account, the present study aimed to examine differences between MwA patients and HCs in sensory processing sensitivity factors, high sensation seeking factors, depression, and anxiety. Mentioned variables were also used to determine their predictive role in predicting the group membership (MwA patients vs HCs). The Highly Sensitive Person Scale, the revised High Sensation Seeking Test, and the Hospital Anxiety and Depression Scale were administered to a sample of seventy-one respondents (39 MwA patients and 32 HCs). MwA patients had a significantly higher score for the low sensory threshold (sensory processing sensitivity factor) in comparison with HCs (4.36 ± 1.4 vs 3.45 ± 1.1, p = 0.003). There was no significant difference in other subscales of sensory processing sensitivity, as well as regarding the high sensation seeking, anxiety, and depression scores, between those two groups. The logistic regression model correctly classified 79.5% MwA patients and 66.7% HCs. The low sensory threshold was a statistically significant predictor for MwA patients (p = 0.001). Our results indicate a certain similarity in the brain sensitivities of MwA patients and people with sensory processing sensitivity trait. Moreover, this shows that the constructs of sensitivity in migraine patients and highly sensitive people overlap to an extent, suggesting the similarity between the conceptualization of sensitivity in the psychological literature and the conceptualization of sensitivity in the medical literature.

Quantitative electroencephalography as a potential biomarker in migraine

OBJECTIVE

The aim of this study was to investigate the utility of quantitative electroencephalography (QEEG) as a diagnostic tool for migraine and as an indicator of treatment response by comparing QEEG characteristics between migraine patients and controls, and monitoring changes in these characteristics alongside clinical symptoms in response to treatment BACKGROUND: We hypothesized that patients with migraine exhibit distinctive characteristics in QEEG measurements, which could be used as potential diagnostic biomarkers and as a tool for monitoring treatment response.

METHODS

A total of 720 patients were included in the study, comprising 619 patients with migraine and 101 subjects as a control group. QEEG measurements were analyzed for absolute power across specific frequency bands: delta wave (0.5-4 Hz), theta wave (4-8 Hz), alpha wave (8-12 Hz), beta wave (12-25 Hz), and high beta wave (25-30 Hz). The absolute power was normalized against a normative dataset from NeuroGuide, with electrodes being highlighted for significance if they exceeded 1.96. Clinical symptoms were also monitored for correlation with QEEG changes.

RESULTS

Our analysis showed that patients with migraine exhibited significantly higher absolute power across all frequencies, most markedly within the high beta frequency range. When considering electrodes with z-scores exceeding the threshold of 1.96 in the high beta range, a significant association with migraine diagnosis was observed (per 1 electrode increase, OR 1.06; 95% CI 1.01-1.11; p = .012). Moreover, pre- and posttreatment changes in QEEG measurements corresponded with changes in clinical symptoms.

CONCLUSION

Patients with migraine have distinctive QEEG measurements, particularly regarding absolute power and the number of electrodes that surpassed the z-score threshold in high beta wave activity. These findings suggest the potential of QEEG as a diagnostic biomarker and as a tool for monitoring treatment response in migraine patients, warranting further large-scale studies for confirmation and expansion.

Migraine Aura-Catch Me If You Can with EEG and MRI-A Narrative Review

Roughly one-third of migraine patients suffer from migraine with aura, characterized by transient focal neurological symptoms or signs such as visual disturbance, sensory abnormalities, speech problems, or paresis in association with the headache attack. Migraine with aura is associated with an increased risk for stroke, epilepsy, and with anxiety disorder. Diagnosis of migraine with aura sometimes requires exclusion of secondary causes if neurological deficits present for the first time or are atypical. It was the aim of this review to summarize EEG an MRI findings during migraine aura in the context of pathophysiological concepts. This is a narrative review based on a systematic literature search. During visual auras, EEG showed no consistent abnormalities related to aura, although transient focal slowing in occipital regions has been observed in quantitative studies. In contrast, in familial hemiplegic migraine (FHM) and migraine with brain stem aura, significant EEG abnormalities have been described consistently, including slowing over the affected hemisphere or bilaterally or suppression of EEG activity. Epileptiform potentials in FHM are most likely attributable to associated epilepsy. The initial perfusion change during migraine aura is probably a short lasting hyperperfusion. Subsequently, perfusion MRI has consistently demonstrated cerebral hypoperfusion usually not restricted to one vascular territory, sometimes associated with vasoconstriction of peripheral arteries, particularly in pediatric patients, and rebound hyperperfusion in later phases. An emerging potential MRI signature of migraine aura is the appearance of dilated veins in susceptibility-weighted imaging, which may point towards the cortical regions related to aura symptoms ("index vein"). Conclusions: Cortical spreading depression (CSD) cannot be directly visualized but there are probable consequences thereof that can be captured Non-invasive detection of CSD is probably very challenging in migraine. Future perspectives will be elaborated based on the studies summarized.

Whole brain surface-based morphometry and tract-based spatial statistics in migraine with aura patients: difference between pure visual and complex auras

Background

The migrainous aura has different clinical phenotypes. While the various clinical differences are well-described, little is known about their neurophysiological underpinnings. To elucidate the latter, we compared white matter fiber bundles and gray matter cortical thickness between healthy controls (HC), patients with pure visual auras (MA) and patients with complex neurological auras (MA+).

Methods

3T MRI data were collected between attacks from 20 patients with MA and 15 with MA+, and compared with those from 19 HCs. We analyzed white matter fiber bundles using tract-based spatial statistics (TBSS) of diffusion tensor imaging (DTI) and cortical thickness with surface-based morphometry of structural MRI data.

Results

Tract-based spatial statistics showed no significant difference in diffusivity maps between the three subject groups. As compared to HCs, both MA and MA+ patients had significant cortical thinning in temporal, frontal, insular, postcentral, primary and associative visual areas. In the MA group, the right high-level visual-information-processing areas, including lingual gyrus, and the Rolandic operculum were thicker than in HCs, while in the MA+ group they were thinner.

Discussion

These findings show that migraine with aura is associated with cortical thinning in multiple cortical areas and that the clinical heterogeneity of the aura is reflected by opposite thickness changes in high-level visual-information-processing, sensorimotor and language areas.