Spontaneous closure of a dural arteriovenous fistula associated with acute hearing loss.

Abstract

Dural arteriovenous malformations (A VMs) are a rare entity, accounting for 10%-15% of cranial AVMs. Sporadic reports of spontaneous regression of these arteriovenous shunts have appeared in the literature and support this event. How­ ever, the mechanism of regression has to date only been speculative. We report a case of spontaneous disappearance of an arteriovenous fistula in the middle ear associated with acute hearing loss and propose a hypothesis for its occur­ rence. Case Report A 60-year-old woman had a 2 year history of pulsatile tinnitus behind the right ear. A right neck and cranial bruit was audible. She gave no history of previous trauma, hearing loss, or vertigo. A tentative diagnosis of jugulotympanic paraganglioma (glomus tumor) was made, and the patient was referred for arteriography. A fistula between the inferior tympanic branch of the ascending pharyngeal artery and the jugular vein was identified (fig . 1 A) . Direct coronal computed tomographic (CT) scans were obtained with the patient in a prone position with her neck hyperextended about 45°. She expe­ rienced total loss of hearing in her right ear, as well as cessation of her pulsatile tinnitus during scanning. Angiography was repeated 6 weeks after the CT scan. The ascending pharyngeal artery could not be subselected, and, thus, a global external carotid angiogram was obtained. The previously demonstrated fistula could not be identified (fig. 18).