Dural arteriovenous shunts involving the sphenoparietal sinus: a case report.

A 40-year-old male suffered transient global amnesia and was diagnosed as having a very rare location of dural arteriovenous shunt (dAVS) involving the right sphenoparietal sinus. The feeding pedicles of dAVS were not only arising from the right external carotid system, including the middle meningeal artery, but also the right internal carotid system including the ophthalmic artery. The dAVS drained into the right sphenoparietal sinus, right vein of Labbe, and right basal vein of Rosenthal through numerous dilated temporal cortical veins. The arteriovenous shunt itself was located at the dura around the right superior ophthalmic fissure and a large varix received direct shunting blood flow from the right sphenoparietal sinus. The dAVS was cured by drainer clipping following transarterial embolisations. A dAVS with cortical venous drainage is considered to have a higher risk of haemorrhage and venous infarction than the others and thus warrants treatment even if the clinical symptom is minimal. If the dAVS has a single drainer, it will be easily cured by way of drainer clipping. Preoperative embolisation makes clipping easier and safer. Intraoperative angiography is useful because preoperative angiography may not necessarily show the complete angioarchitecture around the lesion.