Treatment Efficacy of Forced Prolonged Position After Cupulolith Repositioning Maneuver in Apogeotropic HSCC BPPV

Objectives: To evaluate the therapeutic efficacy of the forced prolonged position (FPP) in patients with horizontal semicircular canal (HSCC) cupulolithiasis in whom the cupulolith repositioning maneuver (CuRM) failed. Methods: Fifty-four consecutive patients with HSCC cupulolithiasis were included, and immediate treatment efficacy of CuRM and short-term treatment efficacy of FPP were investigated. Results: We performed the CuRM in HSCC cupulolithiasis, and, if the CuRM did not show immediate success, instructed the patients to perform the FPP or the sham position (by random allocation) at home. The immediate therapeutic success of the CuRM was assessed by the absence of nystagmus and vertigo on positional testing after 30 minutes of the maneuver, which was 14.8% on the first visit day. And the resolution rate of HSCC cupulolithiasis was higher in the FPP group than in the sham position group at the second (78.3% vs 55.6%), third (75.0% vs 42.9%), and fourth visits (100% vs 25.0%). Conclusion: Although the CuRM has been considered to be a good therapeutic option for HSCC cupulolithiasis because it theoretically aims to detach otoconial particles attached both on the utricle and canal sides of the cupula, the immediate success rate was only 14.8% at the first visit. The FPP can be additionally recommended to improve the resolution rate in HSCC cupulolithiasis patients in whom the CuRM fails.