Reduced trigeminovascular cyclicity in patients with menstrually related migraine

Objective: A case-control study to investigate the effect of the menstrual cycle on trigeminal nerve-induced vasodilation in healthy women and patients with menstrually related migraine (MRM). Methods: Using a laser-Doppler imager, we compared the vasodilator effects of capsaicin application and electrical stimulation (ES) on the forehead skin, a trigeminal nerve-innervated dermatome, in premenopausal patients with MRM (n = 22), healthy controls (n = 20), and postmenopausal women without migraine (n = 22). Blood samples were collected for female sex hormone measurements. Results: Dermal blood flow(DBF) responses to capsaicin were higher in controls during days 1-2 than during days 19-21 of their menstruation cycle (mean E-max +/- SEM: 203 +/- 28 AU vs 156 +/- 27 AU [p = 0.031] for 0.06 mg/mL capsaicin and 497 +/- 25 AU vs 456 +/- 24 AU [p = 0.009] for 6.0 mg/mL capsaicin). In contrast, patients with MRM demonstrated DBF responses without significant cycle-dependent variability (days 1-2 vs days 19-21: E-max 148 +/- 20 AU vs 154 +/- 20 AU [p = 0.788] for 0.06 mg/mL capsaicin and 470 +/- 17 AU vs 465 +/- 20 AU [p = 0.679] for 6.0 mg/mL capsaicin). DBF responses to ES were not different between either patients with MRM or controls, at either occasion. Estradiol levels on days 19-21 of the menstrual cycle were higher in healthy controls (mean +/- SEM: 75 +/- 8 pg/mL) than in patients with MRM (52 +/- 4 pg/mL, p = 0.014). In postmenopausal women, DBF responses to capsaicin and ES, as well as estradiol levels at both visits, were all significantly reduced compared to patients with MRM and controls (in all cases, p < 0.05). Conclusions: Our study provides evidence for a reduced menstrual cyclicity of both estradiol levels and the trigeminovascular vasodilator system in patients with MRM.