Cerebral Venous Thrombosis and Venous Infarction: Case Report of a Rare Initial Presentation of Smoker's Polycythemia

INTRODUCTION: Cerebral venous thrombosis is a rare initial presentation of polycythemia. If diagnosed early, treatment can reduce mortality and morbidity significantly. Often it may present with headache as the only complaint, and thus the diagnosis is likely to be missed. CASE PRESENTATION: A medically stable 31-year-old male, a chronic smoker with a ∼17 pack-year history of smoking, was admitted to the emergency room with a 2-week history of gradually worsening, severe, throbbing headache in the occipital region sensitive to light. Initial neurological examination was positive only for some involuntary motor tics of the left leg. Initial laboratory workup showed hemoglobin of 20 g/dl and hematocrit of 56.5%. The carboxyhemoglobin level was normal, but the oxygen dissociation curve was shifted to the left. Further evaluation by MRI and MRA of the brain suggested extensive and complete thrombosis of the superior sagittal sinus, right transverse sinus and right sigmoid sinus with a small venous infarct in the right parafrontal region. Given that the patient first presented with a thrombotic event, workup for primary polycythemia and hypercoagulable disorders was carried out, including JAK2 mutation evaluation, which was negative. This left us with smoking as the only risk factor and possible cause for secondary polycythemia. He improved significantly with phlebotomy and anticoagulation treatment. CONCLUSION: This case illustrates a rare but severe complication of secondary polycythemia stressing the importance of being aware of the risk of developing cerebral thrombosis in patients with chronic smoking exposure.