[Essential thrombocythemia as a cause of headache in young woman].

A case of severe headache in a young woman is described. The headache was not associated with additional neurological findings. In peripheral blood extremely high count of platelets was found. Additional examinations supported the diagnosis of essential thrombocythemia (ET). As a first line treatment thrombocytapheresis was performed. The introduced hydroxyurea treatment was complicated with dysmenorrhea and neutropenia. It was the reason to the use anagrelide--a new antiplatelet drug--in the therapy of ET. The treatment with anagrelide was free of previously mentioned complications. After one year of observation the platelet count was still effectively reduced.