This article describes several clinical cases of acute ischemic stroke among patients suffering from essential thrombocytemia. Ambiguity of etiological factors of stroke is demonstrated among patients with this pathology. Thrombocytosis and high allele load in the Jak2 gene play an important role (even with normal platelet count) in progression of cerebrovascular disease. Also the question of effectiveness of preventive and etiological therapy is considered.
Keywords: acute ischemic stroke; blood coagulation system; cerebrovascular disease; endothelial dysfunction; haemotology; myeloproliferative disorders; thrombosis.