Catamenial epilepsy is characterized by an increase in seizures during particular phases of the menstrual cycle. We present two patients, aged 17 and 42 years, who experienced generalized tonic-clonic seizures only during the menstrual cycles. Both patients did not benefit from antiepileptic agents used (sodium valproate, phenytoin). However, continuous phenobarbital treatment resulted in an obvious clinical improvement. The patients have been free of seizures for 10 and 16 months, respectively.

Keywords: Anticonvulsants; convulsions/drug therapy;epilepsy/physiopathology/therapy; menstrual cycle;menstruation; ovulation; phenobarbital/therapeutic use;pregnancy; seizures/etiology/drug therapy