The cavernous sinus is a dural venous sinus in the skull that is adjacent to the temporal bone and the sphenoid bone. The carotid cavernous fistula is a type of arteriovenous fistula that causes arterial blood to enter the cavernous sinus. Clinical findings include head, ocular, and facial pain, pulsatile proptosis, chemosis, periorbital edema, conjunctival injection, double vision, glaucoma and, visual loss.