Bilateral proptosis, dilatation of conjunctival veins, and papilloedema: a neuro-ophthalmological syndrome caused by arteriovenous malformation of the torcular herophili.

A patient with an occipital dural arteriovenous malformation (AVM) developed signs of a carotid-cavernous sinus fistula and raised intracranial pressure. Bilateral transverse sinus occlusion associated with the AVM produced these signs by rerouting intracranial venous drainage anteriorly through the cavernous sinuses and superior ophthalmic veins. Angiography and computerised tomographic reformation techniques were used to define these extraordinary cranio-orbital venous pathways.