Electrophysiological response patterns of primary sensory cortices in migraine.

Migraine is an ictal disorder characterised by a particular vulnerability of patients to sensory overload, both during and outside of the attack. Central nervous system dysfunctions are supposed to play a pivotal role in migraine. Electroneurophysiological methods, which aim to investigate sensory processing, seem thus particularly appropriate to study the pathophysiology of migraine. We have thus reviewed evoked potential studies performed in migraine patients. Although results are in part contradictory, these studies nonetheless demonstrate an interictal dysfunction of sensory cortices, and possibly of subcortical structures, in migraine with and without aura. The predominant abnormality is a deficient habituation of evoked responses to repeated stimuli, probably due to cortical, and possibly widespread neural, "dysexcitability".