Teaching NeuroImages: Chronic sinus thrombosis with patency of occipital and falcine cerebral venous sinuses

A 42-year-old woman was referred to the emergency department for severe, drug-resistant headache, persisting since 4 weeks. Neurologic examination was unremarkable. CT venography and magnetic resonance angiography (figure) showed occlusion of the sagittal, rectus, and right sigmoidal sinus and of the right jugular vein, and ectasia of cortical veins, including tentorial veins, the falcine, and the occipital sinus. The falcine sinus usually involutes after birth,1 but thrombosis of this sinus have been described.2 It may become visible in neuroimaging if the straight sinus is thrombosed. The occipital sinus pericranii is the smallest dural venous sinus. The simultaneous patency of these alternative venous drainages is consistent with a compensatory mechanism for chronic dural sinus thrombosis.