Background: Although migraines are estimated to affect up to 10% of the population (2), they remain highly under-diagnosed and under-treated and have a heavy functional, social and economic impact on these individuals and society (3-6). It is assumed that managing a migraine episode in the prodromal phase, when symptoms are not yet present, could reduce the intensity or even prevent the onset of the ictal phase (19, 28). Since 2015, with the study by Pagán et al, we have known that it is possible to predict migraines in the prodromal phase by analysing Heart Rate Variability (HRV) parameters, which reflect variations in the autonomic nervous system (ANS) (35, 40). The main objective of this study was to detect Heart Rate Variabilty changes in the different phases of the migraine on a larger sample scale that the above-mentioned study.
Methods: We conducted a prospective observational study including 7 women with migraines without aura. They filled in an electronic diary to record their migraine attacks during the 3 months of the study and wore a wearable wrist device called Empatica E4 with numerous sensors including a plethysmograph. This enabled us to extract the heart rate and interbeat 24 hours and 30 minutes before and 30 minutes after the onset of the migraine attack. Then we calculated the HRV parameters that we analysed using mixed linear regression and added age as a covariable.
Results: We found a decrease in the parasympathetic activity during the headache phase when we compare it to the premonitory phase. We also found a decrease in the sympathetic activity during the headache phase when we compare it to the end of the premonitory phase.
Conclusion: We therefore found variations in ANS during the phases of migraine, which is encouraging for the early detection of migraine by wearable devices. This pilot study also highlighted limitations in the method that need to be addressed. This type of study needs to be repeated on a larger sample and with different types of migraine to best reflect the reality of migraine sufferers.