A patient with diplopia had a carotid cavernous fistula associated with a p
ersistent primitive trigeminal artery that was seen with angiography. Ballo
on occlusion of the carotid cavernous fistula resulted in flow stasis of th
e persistent primitive trigeminal artery and resolution of the symptoms. Pe
rsistent primitive trigeminal artery may be associated with a carotid caver
nous fistula.