She was booked for an urgent CT scan, which was performed the same day.
The scan showed enlarged muscles in the right eye but more significantly a very large right superior ophthalmic vein (Figure 4). Further history obtained at this stage revealed an episode of bifrontal headache and eye pain 4 months prior.
She was referred urgently to the neurosurgeons with a working diagnosis of a caroticocavernous fistula. Cerebral angiography confirmed the diagnosis by demonstrating a fistula fed by the meningio-hypophyseal branch of the left internal carotis artery and a branch from the left external carotid artery. Drainage appeard to be via the superior ophthalmic vein which appeared thrombosed.