Simulation study of BPPV fatigability
Abstract To analyze the mechanism and clinical significance of BPPV fatigability and discuss how to eliminate BPPV fatigability. A physical simulation model of BPPV was developed to analyze the effects of the Dix-Hallpike test and different angles of bowing maneuver on otolith positions. Dix-Hallpike test can keep the otoliths in the lower arm of the posterior semicircular canal away from the ampulla. The otoliths located in the lower arm of the posterior semicircular canal, slide closed to the ampulla while tilting the head forward more than 30 degrees; slide to the bottom of the crista ampullaris while tilting the head forward more than 60 degrees. The otoliths located in the short arm of the posterior semicircular canal leave the short arm and enter the utricle while tilting the head forward more than 120 degrees. It is recommended that tilting the head forward at least 60° so that the nystagmus induced by repeated Dix-Hallpike tests is consistent with long latency and fatigability is eliminated,which will be an important basis for the diagnosis of BPPV.