Abstract
BACKGROUND: Pulsatile tinnitus (PT) is a type of tinnitus characterized by a rhythmic sound that is synchronous with the heartbeat. One of the possible causes of PT is the jugular bulb wall dehiscence (JBWD). However, the hemodynamics of this condition are not well understood. To elucidate this issue, the present study aimed to compare the blood flow of PT patients with JBWD, PT patients with sigmoid sinus wall dehiscence (SSWD), and volunteers. METHODS: A retrospective case-control study was conducted, which enrolled patients with unilateral PT who had undergone both computed tomography angiography (CTA) and four-dimensional (4D) flow magnetic resonance imaging (MRI) examinations at the Department of Otolaryngology-Head and Neck Surgery of Beijing Friendship Hospital affiliated to Capital Medical University between January 2019 and July 2023. After excluding the possible causes of PT, the patients were divided into the JBWD group and SSWD group according to the presence or absence of JBWD and/or SSWD. Finally, 11 female unilateral PT patients with JBWD (JBWD group, 11sides), 22 age- and side-matched female patients with SSWD (SSWD group, 22 sides), and 22 age-matched female volunteers (volunteer group, 36 sides) were enrolled. The area, maximum voxel velocity (V(v-max)), maximum velocity (V(max)), average velocity (V(avg)), and average blood flow rate (Q) were measured in the transverse sinuses (TSs), sigmoid sinuses (SSs), and jugular bulb (JB). The vortex flow pattern was also assessed. Fisher's exact test and Bonferroni correction were used for count data, with P<0.017 was considered statistically significant. Shapiro-Wilk test, one-way analysis of variance (ANOVA), Kruskal-Wallis H test, paired-samples t-test, and Wilcoxon matched-pairs signed-rank test were used for continuous variables depending on the distribution and variance of the data. The P<0.05 and corrected P<0.05 was considered statistically significant. RESULTS: The area and Q of TSs and JB on the symptomatic side were higher than those on the contralateral side in the JBWD group (TSs: P(area)=0.004, P(flow)=0.002; JB: P(area)=0.034, P(flow)=0.018). The area was larger and velocities were lower in the JBWD group at the TSs than the SSWD group (P(area)=0.004, P(Vv-max)=0.009, P(Vmax)=0.021, P(Vavg)=0.026), and velocities were higher at the distal TSs and SSs than the volunteer group (TSs: P(Vv-max)=0.042, P(Vmax)=0.046, P(Vavg)=0.040; SSs: P(Vv-max)=0.007, P(Vmax)=0.001, P(Vavg)=0.001). At the JB, the JBWD group also had higher V(v-max) than the volunteer group (P=0.012). The occurrence rate of vortex at JB in the JBWD group was higher than both the JBWD and the volunteer groups (P=0.002<0.017 and P=0.009<0.017, respectively). CONCLUSIONS: The blood flow of the intracranial venous sinus was different between the JBWD group and the SSWD group. The indicators that can differentiate include V(v-max), V(max), V(avg), vortex, and TSs cross-sectional area.