Dural Venous Sinus Arachnoid Granulations in Patients with Pulsatile Tinnitus

To determine the relationship, if any, between dural venous sinus arachnoid granulations (AGs) and pulsatile tinnitus.

Retrospective case-control study.

Between October 1999 and March 2020, magnetic resonance imaging of patients with tinnitus (pulsatile [PT] and nonpulsatile [NPT]) were assessed for the presence of dural venous sinuses AG. During the same interval, patients with AGs found incidentally on all magnetic resonance imagings ordered without an indication of tinnitus were reviewed. Demographic variables recorded included patient age, sex, race, body mass index, and a history of idiopathic intracranial hypertension (IIH) or obstructive sleep apnea. Location of AGs, when present, were recorded.

A total of 651 (PT 250, NPT 401) were found to have AGs. AGs had a higher prevalence in PT patients (10.4% [n = 26]) versus NPT patients (0.3% [n = 1]; odds ratio, 31.0; confidence interval 4.1-234; p < 0.001). Of the 77,607 patients who had an indication for imaging other than tinnitus, 230 patients (0.30%) were found to have incidental AGs, suggesting that the NPT cohort was an adequate control. Patients with PT were more likely to have a higher body mass index, be female, be non-White, and have an existing diagnosis of IIH. For all patients with AGs, AGs were more likely to be found in the lateral sinuses (i.e., sigmoid, transverse) in the PT group (odds ratio, 8.1; confidence interval, 1.1-61.1; p = 0.0218).

This study evaluates the association between AG and PT, finding higher rates of AG in patients with PT than in NPT. However, despite the increased prevalence of AG in patients with IIH, these data combined with existing literature would suggest that AGs are not necessarily the missing link to explain PT pathophysiology in IIH.