Interrelations between the cerebral cortex and the trigeminal system: studies in healthy subjects and in migraine patients therapeutic perspectives

Understanding migraine pathophysiology is probably the most challenging point in migrainemanagement, since an efficient acute and preventive treatment should rely on clearpathophysiological bases. Migraine is characterized interictally by a lack of habituation ofevoked responses, possibly due to a decreased preactivation level of sensory cortices. Bycontrast, during an attack and in chronic migraine, the preactivation level increases andhabituation normalizes. New neurostimulation techniques could be useful to durably modifythe activation of the underlying cortex, decreasing the repetition of attacks, giving alsoinsight on the pathophysiology of migraine.The visual cortex plays a pivotal role in migraine pathophysiology, but its effect on thetrigeminal nociceptive system remains poorly understood. On the other hand migraine attackis often associated to photophobia, but the pathophysiological relation between headache andthe discomfort to the light, during the ictal but also the interictal phase, is unclear.This thesis puts a new insight into the relation between the visual cortex modulation and theresponse of the trigeminal nociceptive system, showing a possible inhibitory functionalinterrelation between these structures, via thalamic modulation.The hypothesis is based on our first finding investigating the modulation of the visual cortexby the repetitive transcranial magnetic stimulation on the nociceptive blink reflex in healthysubjects and migraine patients.This role of the activation of the visual cortex is also better understood by using the flash lightstimulation, and thanks to the conception of a new device of flash light stimulation, weperformed several protocols in healthy subjects and migraine patient with the final result aproof-of-concept trial using the flash light stimulation in migraine patients.