Isolated third nerve palsy with pupillary involvement resulting from carotid-cavernous sinus fistula: A case report

Isolated third nerve palsy with pupillary involvement caused by a posterior drainage carotid-cavernous sinus fistula (CCF) is relatively rare. Diagnosis of a posterior drainage CCF can often be delayed due to its unapparent congestive signs.

Here, we present the case of a young male patient with right-sided CCF, who presented with right-side headache and partial third nerve palsy with pupillary involvement. The diagnosis was confirmed using time-of-flight magnetic resonance angiography (TOF-MRA) and digital subtraction angiography (DSA).

A right-sided CCF was detected, which was primarily supplied by the dural branch of the right middle meningeal artery and venous drainage into the right inferior petrosal sinus.

The patient was treated with transarterial coil embolization.

At 2 months, ride-side headache was significantly improved and ptosis and limited extraocular muscle movement were partially resolved.

CCF might not always present with ocular congestion. Although uncommon, white-eye and painful third nerve palsy with pupillary involvement may be caused by a posterior drainage CCF.