A fistula between a carotid artery and the cavernous sinus (carotid-cavernous fistula, CCF) can occur in a number of conditions.
Conditions associated with a CCF:
(1) head trauma
(2) rupture of a small aneurysm
(3) Ehlers Danlos syndrome
(4) pregnancy
(5) iatrogenic
Rare cases will have no preceding event and can be termed idiopathic.
