Application Of Vestibular Autorotation Test In Diagnosis Of Benign Paroxysmal Positional Vertigo

【Objective】The practical value of Vestibular Autorotation Test(VAT) in diagnosis of BPPV is approached by doing an analysis of the results that BPPV patients get by VAT,and by comparing VAT with other vestibular function examinations.【Method】The analysis of VAT results of 40 patients who were finally diagnosed BPPV in July to September,2007 was made.All the selected patients had detailed medical records and complete results of vestibular function examination,including spontaneous nystagmus,gaze test,ocular dysmetria test, smooth pursuit test,optokinetic nystagmus test,caloric test, positional and positioning nystagmus and VAT.The characteristics of VAT for BPPV patients were classified and refined.【Result】34 BPPV patients(85%) appeared abnormal in VAT, chiefly displaying abnormity in horizontal and/or vertical phase.9 BPPV patients of horizontal semicircular canal appeared abnormity in horizontal phase or reached critical value.Among 24 BPPV patients of vertical semicircular canals, 17 patients appeared abnormity in vertical phase or reached critical value.Among 8 BPPV patients whose positioning test was negative,phase of 6 patients was abnormal and phase of the other two reached critical value.【Conclusion】VAT conduces to clarifying diagnosis of BPPV, especially when the Dix-Hallpike positioning test appears false negative,it can be an effective adjuvanticity examination.The abnormity of phase in VAT reflects disfunction of semicircular canals and it is especially sensitive when horizontal semicircular canal functions abnormally.