Menstrual Cycles Affect Seizure Frequency for Women with Epilepsy


San Diego – In women with epilepsy, having a longer or shorter menstrual cycle reduces ovulation, and lack of ovulation increases seizure frequency, according to research that will be presented at the American Academy of Neurology 58th Annual Meeting in San Diego, Calif., April 1 – 8, 2006. “Ovulation rates are lower among women with epilepsy than in the general population,” said the study’s lead author Andrew Herzog, MD, M.Sc, FAAN, of the Harvard Neuroendocrine Unit at Beth Israel Deaconess Medical Center in Boston, Mass. “It has been suggested that these low ovulation rates may be due in part to menstrual cycles that are longer or shorter than normal, and that lack of ovulation may in turn correlate with increased frequency of seizures, but prospective data are lacking in this population.” To test these hypotheses, the researchers studied menstrual cycle length, ovulation occurrence, and seizure frequency in 100 women during the baseline phase of a larger multi-center study on the use of progesterone for modulation of seizures. Over a three-month period the women recorded menstrual cycle length and seizure occurrence. A rise in progesterone during the middle of the cycle signaled ovulation. The frequency of seizures during cycles with ovulation and cycles where no ovulation occurred was compared in the 30 women who had at least one of each type of cycle during the study. Ovulation occurred in 90 percent of 26-32 day cycles, but declined steeply when cycles were either longer or shorter, occurring in less than 40 percent of either 23- or 35-day cycles. Seizures occurred on average about every four days in ovulatory cycles, and every three days in anovulatory cycles. “These results support the hypothesis that seizure frequency is affected by ovulation,” said Herzog, “and ovulation is correlated with cycle length.” This study was supported by the National Institutes of Health.

The American Academy of Neurology is the world's largest association of neurologists and neuroscience professionals, with 34,000 members. The AAN is dedicated to promoting the highest quality patient-centered neurologic care. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as Alzheimer's disease, stroke, migraine, multiple sclerosis, concussion, Parkinson's disease and epilepsy.

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Editor's Notes:Dr. Herzog will present this research during a scientific poster session between 3:00 p.m. and 7:00 p.m. on Thursday, April 6 in the Sails Pavilion of the San Diego Convention Center. April 1 - April 7, 2006 contact (619) 525-6207 He will be available for media questions during a briefing at 1:00 p.m. Thursday, April 6 in the on-site Press Interview Room, room 16 B. All listed times are for Pacific Time (PT). AAN Press Room in the San Diego Convention Center April 1 - April 7, 2006 contact (619) 525-6207


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