Otic vesicle An epithelial sac behind the fifth rhombomere forming the semicircular canals dorsally and the otolith organs ventrally.

耳小囊形成于半规管背与耳石器官且在第五脑特殊节状结构一个上皮囊。

Singular neurectomy (posterior ampullary nere transsection) and posterior semicircular canal occlusion are the 2 specific techniques used in intractable BPP surgery.

单经切除术（经）和半规管闭塞术是应用于难治性良性阵发性位置性眩晕两种特殊手术治疗技术。

Conclusion: The therapy effect of PRM was superior to postural striction, and all patients should be treated by PRM when the diagnosis of posterior semicircular canal BPPV was uncle.

PRM治疗效果明显优于体位限制治疗，凡半规管BPPV诊断明确者均应给予PRM治疗。