Background: Migraine triggered by oral contraception (OC)-free interval is very common and may be extremely severe, long-lasting and poorly responsive to analgesics (status migrainosus). The serotoninergic (5-HT) system is crucially involved in pain threshold and it is sensitive to estradiol (E2). Therefore, we aimed to assess neuroendocrine correlates of OC status migrainosus in response to the direct central 5-HT agonist meta-chlorophenylpiperazine (m-CPP) and to test the effect of transdermal E2 supplementation of the OC-free interval.
Methods: Clinical investigative protocol, single-blinded placebo-controlled treatment. Oral m-CPP (0.5 mg/kg body weight) challenge test was performed in 10 patients with status migrainosus occurring within 48 h of the discontinuation of a monophasic pill (30 microg of ethinyl estradiol and 150 microg of desogestrel) and in six healthy women assuming the same OC as controls. In a consecutive menstrual cycle, patients with OC status migrainosus underwent to the same test after they were blindly treated with 2.0 g of percutaneous E2 gel or placebo daily during the pill-free interval. Plasma prolactin and cortisol levels and clinical characteristics of migraine attacks were evaluated.
Results: Women with OC-status migrainosus showed a derangement of prolactin release (F = 4.8; P < 0.01) and a lack of cortisol response (F = 5.8; P < 0.001) after m-CPP in comparison with controls. Transdermal E2 during the pill-free interval significantly restored prolactin (F = 2.8; P < 0.01) and cortisol responses (F = 18.9; P < 0.001) against placebo and positively affected the duration (P < 0.001), the number of hours in which pain intensity prohibits daily activity (P < 0.001), the episodes of vomiting (P < 0.001) and the consumption of analgesics (P < 0.001).
Conclusions: Status migrainosus triggered by OC-free interval is associated with impaired prolactin and cortisol responses following m-CPP challenge. Transdermal E2 supplementation is able to restore neuroendocrine response to this specific 5-HT agent, exerting a positive clinical effect on the course of menstrually related migraine.