Dural cavernous sinus fistula: an unusual presentation.

This article describes a 22-year-old man who presented to the Howard University Hospital emergency room with acute onset of swelling, proptosis, and decreased vision in the right eye preceded by 24 hours of nausea and vomiting. The patient's visual acuity was count fingers in the involved eye with marked proptosis and limitation of ocular motility. There was no history given of any ocular or head trauma. A computed tomography scan of the orbits showed diffuse symmetric enlargement of the extraocular muscles of the right eye, felt to be consistent with an orbital inflammatory pseudotumor. The patient was treated with intravenous steroids initially, then placed on oral prednisone. After minimal improvement on the steroids, a selective external carotid angiogram showed a moderate-sized dural cavernous sinus fistula. The patient underwent selective embolization of the fistula with rapid resolution of periorbital edema and proptosis. Visual acuity was stabilized at 20/200 in the right eye. The differential diagnosis and pathogenesis of carotid cavernous sinus fistulas and the likely pathogenesis of the fistula in this case are discussed.