Effects of Pattern-Reversal Visual Stimulation on Brain Activity in Migraineurs and General Population

Background: A better understanding of migraine pathophysiology through standardized methods could facilitate the development of more effective therapeutic approaches for migraine sufferers. However, neurophysiological studies with migraine sufferers present larger variability, as most contain only a single measurement. Objective: This observational study aimed to compare the cortical and visual excitability of migraine sufferers, individuals with other types of headaches, and healthy participants in response to pattern-reversal visual stimulation. Methods: Fifty-nine individuals were classified by a neurologist into the following groups: (i) migraineurs (n = 25); (ii) other types of headaches (n = 23); (iii) healthy (n = 11). Habituation during pattern-reversal visual stimulation was assessed by visual evoked potentials. Visual and motor cortex excitability were evaluated before and after pattern-reversal visual stimulation. Results: We found no intergroup differences in motor and visual excitability measures after pattern-reversal visual stimulation. Compared to the healthy group, migraineurs and individuals with other types of headaches displayed a reduction in phosphene threshold after pattern-reversal visual stimulation. Additionally, an increase in visual cortical excitability in these groups was also observed. Lastly, the habituation in individuals with migraines and other types of headaches was lower compared to healthy individuals. Therefore, the lack of habituation may not be exclusively associated with the pathophysiological mechanisms of migraine. Conclusion: Individuals who experience headaches, including migraineurs, have an increased visual cortical excitability in response to visual stimuli. This finding is promising for guiding future neurophysiological research to identify cortical biomarkers in migraineurs and in other types of headaches.