The superior sagittal sinus runs in the midline along the superior border of the falx cerebri from the foramen cecum anteriorly to the internal occipital protuberance, where it drains into the confluence of sinuses (torcular Herophili) and thence into the transverse sinuses. It receives cortical bridging veins from both cerebral hemispheres and communicates with the diploeic veins and scalp veins through emissary veins.
The superior sagittal sinus is the most common site of cerebral venous sinus thrombosis (CVST), which occurs in hypercoagulable states, pregnancy, oral contraceptive use, dehydration, and head trauma. CVST presents with headache, papilloedema, focal deficits, and seizures from venous infarction. MRI with venography demonstrates the classic empty delta sign (filling defect in the sinus on contrast imaging). Parasagittal meningiomas arise from the sinus wall and may invade and occlude it. The sinus is at significant risk during parasagittal approaches to the brain and its bridging veins must be preserved to prevent venous infarction.
Thrombosis of the superior sagittal sinus causes raised intracranial pressure with headache, visual obscurations, and papilloedema; venous infarctions may produce focal deficits and seizures; anticoagulation with heparin is the standard treatment even in the presence of haemorrhage.
Meningiomas arising from the sinus wall may invade and partially or completely occlude the superior sagittal sinus; surgical resection of the tumour and sinus requires assessment of collateral venous drainage before resecting an invaded sinus segment to avoid catastrophic venous haemorrhage and cerebral swelling.
