Objective.—To examine the role of matrix metalloproteinase 9 (MMP-9) in migraine during headache and asymptomatic periods.
Methods.—Thirty-four patients with migraine with and without aura (according to International Headache Society criteria) were studied. Clinical characteristic of headache were recorded. Blood samples for measurement of MMP-9 were drawn during headache attacks and during asymptomatic periods in all patients and in 10 healthy controls.
Results.—We found higher plasma MMP-9 levels in migraine patients than in control group (129.3 [78.0–258.9] vs. 49.6 [39.1-64.3] ng/mL; P < .001). Migrainous patients showed higher MMP-9 plasma levels during headache attacks than in asymptomatic periods, both in migraine without aura (338.4 [275.1–396.2] vs. 118.2 [75.3–137.5] ng/mL; P < .0001), and migraine with aura (389.3 [273.4–487.1] vs. 139.3 [107.3–191.4] ng/mL; P < .0001).
Conclusions.—Our study showed an increased production of MMP-9 during migraine attacks. These data suggest a possible role of inflammation or blood–brain barrier disruption during the migraine attack.