Analysis of the duration of migraine prophylaxis.

To determine the minimum duration of migraine prophylaxis, after patients become pain-free. Migraine patients diagnosed according to criteria of International Classification of Headache Disorders-2 were treated prophylactically. After becoming pain-free, they were divided into two equal groups: in group 1, prophylaxis was maintained for another 12 months and in group 2, for 24 months.