Endocrine Abstracts

Cerebral venous sinus thrombosis (CVST) represents approximately 0.5-1% of all patients with strokes. It is associated with conditions resulting in a hypercoagulable state, typically occurring in young women during pregnancy and taking the combined oral contraceptive pill (COCP). Thyrotoxicosis is a predisposing factor in 1.7% of patients with CVST. A 26-year-old female presented with acalculus cholecystitis. Doppler ultrasound of liver demonstrated turbulent flow through hepatic veins suggestive of right heart dysfunction. Echocardiogram showed an estimated ejection fraction of 40%. She was thyrotoxic; TSH <0.01 (0.4-4.2IU/l) and Free T4 (FT4) 35.2 (12-22 pmol/l). Her TRAb was positive 19.8 (<0.8IU/l) confirming Graves’ disease. She commenced anti-thyroid drugs and failed to attend a series of appointments. She returned a number of months later thyrotoxic; TSH <0.01 (0.4-4.2IU/l) and FT4 46.0 (12-22 pmol/l) and pregnant (G ⁴P ¹⁺²). She was managed with antithyroid drugs throughout her pregnancy and delivered a baby at 30 weeks gestation that required a period in neonatal ICU. She had no history of venous thromboembolic disease in prior pregnancies or postpartum period. Over 3 months postpartum, she returned profoundly thyrotoxic; TSH <0.01(0.4-4.2IU/l) and FT4 84.6(12-22 pmol/l). Her dose of antithyroid drug was increased. She represented a number of days later complaining of headache, vomiting and blurred vision. CT brain demonstrated a 14mm hyperdense segment in the region of the right transverse sinus. An MRV confirmed loss of flow void in the right transverse sinus, consistent with right transverse sinus thrombosis. She was commenced on a Dabigatran. Antiphospholipid screen, serum ANCA and JAK mutation were negative. Thyrotoxicosis is associated with hypercoagulable state and possibly endothelial dysfunction mediated via increased levels of fibrinogen, factor VIII, factor IX and VonWillebrand factor. It was felt the patient’s Graves’ disease most likely was a provoking factor in the development of a CVST, which is a rare but known association.