A 23-year-old woman, with a history of cerebral venous sinus thrombosis (CVST) on warfarin, presented with acute septic hemarthrosis, requiring surgery. A cerebrovascular consultation was placed for anticoagulation recommendations. Brain magnetic resonance venography revealed a hypoplastic right transverse sinus (figure). Anticoagulation was discontinued. Given her history of headache and papilledema, acetazolamide was started due to clinical suspicion of idiopathic intracranial hypertension (IIH).