The Incidence of Cranial Arteriovenous Shunts in Patients With Pulsatile Tinnitus: A Prospective Observational Study

Finding the underlying cause for pulsatile tinnitus can be challenging. We aimed to determine the incidence of arteriovenous shunts, i.e., arteriovenous malformations (AVMs) or dural arteriovenous fistulas (dAVFs), in patients referred for catheter angiography (digital subtraction angiography [DSA]). Furthermore, we assessed which clinical features were predictive for the presence of such a lesion.

Fifty-one patients with pulsatile tinnitus, who were referred to us for DSA to exclude an arteriovenous shunt, were enrolled, prospectively.

DSA determined the presence of a dAVF or AVM. Clinical characteristics were recorded systematically and all patients underwent a physical examination.

Fifty patients were included in the final analyses. While no AVMs were found, a dAVF was found in 12 cases (24%). Three of these demonstrated cortical venous reflux, thus requiring treatment due to the risk of hemorrhage. In three cases (6%), DSA demonstrated a non-arteriovenous-shunt abnormality, likely causing the tinnitus. The odds of having a dAVF were significantly raised by unilaterality, objective bruit, and the ability to influence the tinnitus with compression. Unilaterality even had a negative predictive value of 1 and, if used as selection criterion, would have raised dAVF prevalence from 24 to 32%.

In a tertiary care setting, the prevalence of dAVFs in patients with pulsatile tinnitus is not negligible. Thus, patients with unilateral pulsatile tinnitus should be offered dynamic vascular imaging to rule out a dAVF. Especially, since some of these patients are at risk of intracranial hemorrhage and treatment options exist.