[Superior sagittal sinus thrombosis as first manifestation of essential thrombocythemia]

A 52-year-old previously healthy woman was admitted to our hospital for status epilepticus in November 1999. She had not taken oral contraceptives. After treatment with intravenous diazepam and phenytoin, she did not develop seizures anymore. When she became alert, there was a mild left hemiparesis. Lumbar puncture showed an opening pressure of 145 mm H2O, and the cerebrospinal fluid was acellular. Cranial MR imaging demonstrated thrombosis of the superior sagittal sinus and fresh infarction in the right frontal lobe. Plasma fibrinogen, fibrin degradation product, and prothrombin fragment 1 + 2 levels were elevated. Proteins S and C activities and anti-thrombin III levels were within the normal range. Lupus anticoagulant and anti-cardiolipin antibody were negative. She was treated with continuous heparin infusion for ten days and with oral warfarin thereafter. Six months after the first admission, platelet count became more than 400 x 10(3)/microliter. In July 2002, she developed slowly progressive monoplegia of the left arm. Cranial MR imaging demonstrated patent superior sagittal sinus, fresh infarction in the right parietal lobe, and old small infarction in the right corona radiata. The patient was maintained on warfarin and 100 mg of aspirin thereafter. In September 2002, platelet count was 737 x 10(3)/microliter. Bone marrow examination showed increased megakaryopoiesis with normal erythroid and myeloid series and no chromosomal aberrations. Serum C-reactive protein and iron levels were in the normal range. An abdominal ultrasound demonstrated mild splenomegaly. Thus, we made a diagnosis of essential thrombocythemia (ET). ET causes thrombotic events in the course of the disease at a rate of 7% per year. Cerebral infarction is not uncommon, but occurrence of cerebral sinus thrombosis has been rarely reported. Recently, several cases have been reported in which cerebral infarction was the first manifestation of ET even with platelet counts lower than 600 x 10(3)/microliter. To our knowledge, there have been no reported cases of ET presenting with cerebral venous sinus thrombosis. Platelet count should be monitored in the patients with venous sinus thrombosis of undetermined etiology.