Not Just Another Headache: Cerebral Venous Sinus Thrombosis in a Patient With Isolated Antithrombin III Deficiency.

Cerebral venous sinus thrombosis (CVST) is a rare condition. Symptoms and signs arise from a combination of thrombosis of cerebral veins and increased intracranial pressure. The most common presenting symptom is a non-descriptive headache, but presentation varies with underlying etiology. CVST requires a high index of suspicion to diagnose, particularly in those without apparent risk factors. Evaluation and diagnosis should include a combination of a thorough history, ophthalmoscopic examination, laboratory studies, and imaging. Management is multidimensional and aims to reverse the underlying causes, and prompt treatment with anticoagulation by heparin to decrease thrombotic burden, risk of permanent neurological deficits, and death. In the present study, we report the case of a 61-year-old man referred to the emergency department by an ophthalmologist for bilateral papilledema and eventually diagnosed with CVST secondary to isolated antithrombin III deficiency. Although CVST is uncommon, this case is worthwhile to report as the presentation is unique, and it requires a high index of clinical awareness for timely diagnosis and early therapeutic intervention.