Type C Carotid Cavernous Fistula

A patient presented with acute, painless, intermittent double vision. The patient had a past medical history of hypertension, hyperlipidemia, and myocardial infarction. The presenting visual acuity was 20/25 in both eyes with normal pupillary responses and intraocular pressure. The extra-ocular motility was full and there was no blepharoptosis. The posterior segment examination was normal. The patient underwent CT scan of the head which was normal. They were discharged with close-interval follow-up but returned one month later to the ophthalmic emergency room with now persistent double vision, eye redness, and new ”drooping” eyelids. There were no systemic symptoms reported. The visual acuity decreased to 20/40 in the right eye and remained 20/25 in the left eye. The pupillary responses and intraocular pressures were normal. Physical examination revealed restricted elevation, depression, and adduction of both eyes and blepharoptosis of both eyes. There was new bilateral conjunctival injection without follicles or papillae. The posterior segment examination remained normal. The patient underwent MRI and MR angiography of the brain and orbits which revealed a non-specific pre-pontine mass. They were admitted to the hospital for expedited laboratory work-up and appropriate consultations. There was concern for an autoimmune process, such as Miller-Fisher Syndrome or Myasthenia Gravis, resulting in bilateral ptosis and external ophthalmoplegia. The patient had worsening external ophthalmoplegia despite a treatment trial with intravenous corticosteroids. Repeat MRI and MR angiography of the brain revealed arterialized flow in the left cavernous sinus and arterialized flow in the superior ophthalmic veins. A carotid-cavernous fistula was suspected and the patient underwent digital subtraction angiography which confirmed a Barrow Type C carotid cavernous fistula (CCF). The patient underwent coil embolization with improvement in the visual acuity, resolution of the blepharoptosis, and return of full extra-ocular motility. CCF is a difficult diagnosis to make and requires a high index of suspicion. Direct CCF is more commonly traumatic in young, male patients. Indirect, spontaneous CCF is often reported in post-menopausal, hypertensive females. Direct cerebral angiography is the gold-standard in diagnosis and treatment options include elimination of the fistula with detachable balloons, metal coils, and different liquid embolization agents.

Presentation Date: 11/03/2022

Issue Date: 12/16/2022