[Animal models and their results in relation to the therapy of migraine]

Until now, our understanding of migraine pathophysiology has been fairly incomplete. So far no animal model has allowed an explanation of all facets of the clinically heterogeneous condition migraine. However, it is now generally accepted that the migraine headache is due to activation of the trigeminal system. The model of neurogenic inflammation after stimulation of the trigeminal ganglion or systemic administration of capsaicin allows study of the inhibitory interactions between antimigraine compounds and peripheral trigeminal fibre terminals that sustain a sterile meningeal inflammation through release of allogenic and vasoactive neuropeptides, such as substance P and calcitonin gene-related peptide. Studies with the model of superior sagittal sinus stimulation have revealed central actions of antimigraine agents such as ergotamine and sumatriptan, but also acetylsalicylic acid on neurotransmission of trigeminal nociceptive input in the brainstem. A likely explanation for the slowly progressing neurological deficits is cortical spreading depression (CSD), which can easily be elicited in many species. However, CSD has not been observed in vivo in humans. The described models strongly influenced the development of new medications for migraine treatment and have improved our understanding of migraine pathophysiology.