Ischaemic stroke and essential thrombocythemia: a series of 14 cases.

Background: Essential thrombocythemia (ET) is considered as a rare cause of stroke, partially because of difficulties to identify it when platelet count is not greatly elevated. However, early detection of ET is important because, without adapted treatment, recurrent thromboses are frequent.
Method: We collected, retrospectively, data from 14 cases of stroke patients with ET. Clinical characteristics, ischaemic stroke, laboratory data (platelet and leucocyte count, haemoglobin, JAK2 V617F mutation, culture of haematopoietic progenitors) and treatment were reviewed. Every patient has been interviewed by phone to evaluate outcome.
Results: The population consisted of nine women and five men with ages ranging from 40 to 87 years. Most of the patients (12) had atherosclerotic risk factors and two presented a thrombus in the internal carotid. ET was diagnosed early after the onset of stroke except in two patients. The platelet count was under 600*10(9) /L for five patients. Mutation JAK2 V617F was found for eight patients. Thirteen patients were treated with an association between antiplatelet and cytoreductive treatment and did not present further thrombosis. Median follow-up is 2.8 years.
Conclusion: These cases emphasize the problems of diagnosing ET at the onset of the stroke. Complete blood count has to be carefully read and ET can be suspected even if platelet count is not greatly increased. Diagnosis must be confirmed by haematologist to initiate appropriate treatment.
(© 2010 The Author(s). European Journal of Neurology © 2010 EFNS.)