Effect of right-to-left shunt on youth benign paroxysmal positional vertigo: A prospective clinical study.

OBJECTIVE: To evaluate the correlation between right to left shunt (RLS) and youth benign paroxysmal positional vertigo (YBPPV). PATIENTS AND METHODS: Patients with benign paroxysmal positional vertigo (BPPV) and normal control cases younger than 45 years were enrolled at 1:1 ratio. Contrast-enhanced transcranial doppler ultrasound was performed to determine the existence and shunt grading of RLS. Regression analysis was conducted by including other possible risk factors for YBPPV to evaluate whether RLS acts as an independent risk factor. RESULTS: A total of 174 cases were enrolled, with 87 cases in the YBPPV group and 87 cases in the normal control group. The proportion of existing RLS in the YBPPV group was significantly higher than in the normal control group (65.52% vs. 28.74%, P < 0.001). Regression analysis showed that RLS was an independent risk factor for YBPPV (odds ratio = 2.157, 95% credibility interval: 1.504～3.093, P＜0.001). In the YBPPV group, the recurrence of BPPV within 180 days showed no statistical difference between cases with RLS and receiving anti-platelet treatment and cases with RLS and without anti-platelet treatment. In the YBPPV group, the recurrence of BPPV within 180 days in cases without RLS and anti-platelet treatment did not significantly differ from cases with RLS and without anti-platelet treatment and cases with RLS and receiving anti-platelet treatment. CONCLUSION: In the present study, RLS resulted as an independent risk factor for YBPPV. This observation could generate hypotheses of the mechanism by which a RLS could induce YBPPV.