The Relationship Between Paroxysmal Vertigoes and Right-To-Left Shunt: A Large Observational Study

Abstract Background The association between paroxysmal vertigo and right-to-left shunt (RLS) is rarely reported. We investigated the incidence and correlation of RLS in patients with different paroxysmal vertigo diseases. Methods This large observational study included patients with paroxysmal vertigo from seven different hospitals in China from 2017 to 2021 (NCT04939922). Migraine patients within the same period were included for comparison. Demographic data and medical history were collected, contrast transthoracic echocardiography (cTTE) was performed, and the clinical features, dizziness handicap inventory, and incidence of RLS in each group were recorded. Results This study used a consecutive sampling of 4536 patients from seven centres, and a total of 2751 patients were enrolled. The proportion of RLS in patients with migraine with aura (MA), migraine without aura (MoA), vestibular migraine (VM) with headache, VM without headache, and benign recurrent vertigo (BRV) was significantly higher than that in patients with benign paroxysmal positional vertigo (BPPV), Meniere’s disease (MD), and vestibular paroxysmia (VP) (P<0.05). There was no statistical difference between the frequency of RLS in patients with BRV and those with MoA (P=0.931), MA (P=0.997), VM with migrainous headache (P=0.787), and VM without migrainous headache (P=0.754). There was a positive correlation between the RLS grade and the dizziness handicap inventory scores of VM and BRV patients (P<0.01). Conclusions RLS was significantly associated with BRV and VM. RLS may be involved in the pathogeneses of BRV and VM and may serve as a reference index for the differential diagnosis of central and peripheral vertigo. Trial registration: CHRS, NCT04939922, registered 14 June 2021- retrospectively registered, https://register.clinicaltrials.gov