[Application of vestibular autorotation test in diagnosis of benign paroxysmal positional vertigo]

The objective of this study was to evaluate the utility of vestibular autorotation test in the diagnosis of BPPV.

VAT and caloric test were performed on 41 patients with BPPV. VAT results were analyzed according to the affected semicircular canal.

Results of VAT were abnormal in 34 (82.93%) patients with BPPV. Fourteen cases were found with abnormal vertical phase, 1 case with abnormal vertical gain in a total of 21 vertical semicircular canal BPPV patients. Six cases with abnormal horizontal phase lead, 5 cases with abnormal horizontal gain, 2 cases with asymmetry were found in 12 patients with horizontal semicircular canal BPPV. Phase lead was abnormal in all frequencies in 4 patients, and in 2-3 Hz in 21 patients. 24 (58.54%) patients showed abnormal canal paresis (CP) and direction preference (DP) in caloric test.

VAT can indicate information of vestibular function in both vertical and horizontal semicircular canal. Phase of VAT is constantly enhanced in BPPV, especially in 2-3 Hz. As the supplement of caloric test, VAT may prove helpful in assessment of semicircular canal function.