Figure 3. Drawing shows venous drainage of cavernous sinus dural AVFs. 1 = anterior drainage into superior ophthalmic vein (SOV) and inferior ophthalmic vein (IOV), which can lead to ocular symptoms (eg, exophthalmos and chemosis); 2 = posteroinferior drainage into inferior petrous sinus (IPS), basilar plexus, and pterygoid plexus, leading to bruit and cranial nerve deficits; 3 = posterior drainage into superior petrous sinus (SPS), leading to bruit; 4 = cortical reflux into sphenoparietal sinus and superficial middle cerebral vein (SMV), leading to venous infarction and hemorrhage; 5 = cerebellar (spinal) drainage into petrous vein (PV), leading to ataxia and hemorrhage; and 6 = deep drainage into deep middle cerebral vein and uncal vein, leading to hemorrhage. JV = jugular vein, SS = sigmoid sinus, STV = superficial temporal vein.