Of generators, networks and migraine attacks.

Abstract

One of the most discussed topics in migraine pathophysiology is where migraine attacks originate. Although recent evidence suggests central attack generating loci, there is an ongoing debate about the involved centres of the brain and brainstem. Recent neuroimaging studies focussing on the preictal stage of migraine attacks suggest a predominant role of the hypothalamus and its functional connectivity shortly before the beginning of migraine headaches. In interictal migraineurs, changes in resting state functional connectivity of the dorsal pons and the hypothalamus have been found. Based on the clinical presentation of the premonitory phase of migraine, the hypothalamus and changes within the dopaminergic system have been discussed as likely candidates for attack generation. Neuroimaging studies however suggested the dorsal pons as attack generator. Taking into account the recent findings of hypothalamic involvement and changing connectivity in the preictal stage, the available evidence suggests that the idea of a single migraine generator within the human brain is probably too simplistic. More likely, spontaneous oscillations of complex networks lead to activity changes in certain subcortical and brainstem areas. This in turn might constitute functional changes of descending pain-modulating pathways, and thus the generation of migraine pain.