Dural carotid-cavernous sinus vascular malformation with facial nerve paresis.

Facial nerve paresis is rarely seen in dural cavernous sinus arteriovenous malformations or carotid-cavernous sinus fistulae. A patient with an otherwise typical presentation of a spontaneous carotid-cavernous sinus malformation was found to have ipsilateral infranuclear facial nerve paresis. Angiography revealed a dural arteriovenous malformation with early petrosal sinus filling. Possible mechanisms for the paresis include compression of the facial nerve by increased venous pressure and "stealing" of the arterial supply by the malformation.