Three-dimensional simulations of mixed maneuver for three semicircular canalithiasis on the same side

Background The canalith repositioning maneuver (CRM) is an effective method for treating benign paroxysmal positional vertigo (BPPV). Classical CRM is designed mainly for a single semicircular canal (SC). Methods A mixed maneuver (MM) hybridized by classical maneuvers was proposed for otoconia of three SCs on the same side. Simulations of otoconia movement induced by classical CRMs and MM were performed on a 3-axis servo motors platform (SMP) with an iPhone containing the aVOR app. MM was performed on BPPV VIEWER to show the otoconia trajectory. Results The Epley and Barbecue maneuver were effective for the otoconia of posterior semicircular canal (PSC) and horizontal semicircular canal (HSC), respectively. Similarly, the supine roll test + Gufoni maneuver was effective for otoconia of HSC, and the Dix-Hallpike test + Yacovino maneuver was effective for otoconia of ASC. Furthermore, the MM was effective for free-floating otoconia in HSC, ASC and long arm of PSC on the same side. Conclusion The SMP-aVOR model and BPPV VIEWER provide methods for studying otoconia repositioning. The MM showed potential capability to reposition the common types of otoconia in the three SCs on the same side.