Serum Ionized Magnesium Levels and Serum Ionized Calcium/Ionized Magnesium Ratios in Women With Menstrual Migraine

OBJECTIVE: It has been suggested that magnesium deficiency may play an important role in menstrual migraine and that the serum ionized calcium (ICa2+)/ionized magnesium (IMg2+) ratio is important in migraine headache. Studies were designed to test these hypotheses. DESIGN: We prospectively evaluated 270 women seen at a headache clinic and in 61 women with menstrual migraine measured IMg2+, total magnesium, and ICa2+ levels so as to calculate the ICa2+/IMg2+ ratio. RESULTS: The incidences of IMg2+ deficiency were 45% during menstrual attacks, 15% during nonmenstrual attacks, 14% during menstruation without a migraine, and 15% between menstruations and between migraine attacks. The serum ICa2+ levels were within our reference range, but the ICa2+/IMg2+ ratio was elevated (P<.01) in menstrual migraine. CONCLUSIONS: The high incidence of IMg2+ deficiency and the elevated ICa2+/IMg2+ ratio during menstrual migraine confirm previous suggestions of a possible role for magnesium deficiency in the development of menstrual migraine.