Calcitonin gene-related peptide triggers migraine-like attacks in patients with migraine with aura

Introduction: Calcitonin gene-related peptide (CGRP) is a key molecule in migraine pathogenesis. Intravenous CGRP infusion triggers delayed migraine-like attacks in patients with migraine without aura (MO). In contrast to patients with MO, in prior studies patients with familial hemiplegic migraine (FHM) did not report more migraine-like attacks compared to controls. Whether CGRP triggers migraine in patients with typical (non-hemiplegic) migraine with aura is (MA) unknown. In the present study we examined the migraine inducing effect of CGRP infusion in patients suffering from MA and healthy controls. Methods: Fourteen patients suffering exclusively from migraine with typical aura (MA) and 11 healthy volunteers received a continuous intravenous infusion of 1.5 mu g/min CGRP over 20 minutes. Headache and other migraine symptoms were scored every 10 minutes for one hour and self recorded hourly thereafter and until 13 hours post-infusion. Results: CGRP infusion induced significantly more delayed headaches in MA patients (12 out of 14) than in controls (2 out of 11) (p = 0.001). Furthermore, significantly more MA patients (57%; 8 out of 14) fulfilled criteria for an experimentally induced migraine attack after CGRP than controls (0%; 0 out of 11) (P = 0.003). Four patients (28%) reported aura symptoms after CGRP infusion. Conclusion: CGRP triggered migraine-like attacks without aura in patients suffering exclusively from MA. It also triggered a typical aura in 28% of the patients. These data indicate similar neurobiological pathways responsible for triggering migraine headache in MA and MO patients, and suggest differences between MA/MO and FHM.