LEFT DURAL TO RIGHT CAVERNOUS SINUS FISTULA - A CASE-REPORT

Direct carotid-cavernous sinus fistulas that present with signs and sy mptoms contralateral to the arterial supply of the fistulas are not un common. We present a thoroughly documented case of a dural-cavernous s inus fistula with symptoms exclusively contralateral to the arterial s ource, a rarer entity. The patient presented with a red, proptotic rig ht eye and a history of transient horizontal diplopia and a ''feeling of fullness'' in that eye. Magnetic resonance imaging (MRI) of the bra in and orbits performed at another hospital had shown no abnormalities . Carotid angiography performed on the right side was normal; carotid angiography performed on the left side showed a dural-cavernous sinus fistula, with shunting from branches of the left external carotid arte ry directly to the right cavernous sinus. Orbital duplex color-flow so nography showed reverse flow in a dilated right superior ophthalmic ve in. This unusual manifestation of a dural-cavernous sinus fistula offe rs insight into the pathophysiology of arteriovenous fistulas involvin g the cavernous sinus, and is a reminder that bilateral injections are required when performing carotid angiography to characterize these di sorders.