Background: Progesterone with its anti-seizure effect plays a role in the pathophysiology of catamenial epilepsy which affects 31-60% of epileptic women. In this study, an attempt to treat women suffering from catamenial epilepsy with progesterone, as an adjuvant drug, was made.

Methods: The treatment was given to 36 women aged 20-40 years (mean age: 30.75±6.05) with seizures in the entire second half of the menstrual cycle, who were found to have low serum levels of progesterone on days 22, 27, 28 of the cycle in comparison with a control group of healthy women. The patients were administered progesterone in a daily dose of 50 mg on days 16-25 of each cycle. The serum levels of antiepileptic drugs were assayed. The period of progesterone therapy ranged from 3 to 45 months (17.7 on average).

Results: Three patients were free of secondary generalized seizures, and one–of simple partial seizures. A decline in the frequency of primary and secondary generalized seizures by 20-96% (55.9% on average) was accomplished in 18 patients (primary generalized by 20-96%–54.7% on average, and secondarily generalized by 38-85%–59% on average). A decline in the frequency of complex partial seizures by 38-87% (63.1% on average) was achieved in 15 women. In 1 patient, the frequency of myoclonic seizures decreased by 46%. There was no improvement in 5 women (3 patients with generalized, 1 with complex partial and 1 with simple partial seizures). An exacerbation of seizure frequency occurred in 5 patients. Adverse effects were not found in any of the subjects. The average concentrations of antiepileptic drugs during hormonal therapy were in the therapeutic range.

Conclusion: Progesterone combined with antiepileptic therapy was well tolerated and resulted in a significant reduction of seizure frequency in majority of patients with catamenial epilepsy.