Comparative Study on the Roles of the Number of Accelerations and Rotation Angle in the Treatment Maneuvers for Posterior Semicircular Canal Benign Paroxysmal Positional Vertigo.

AIMS

This study aims to investigate the roles of the number of accelerations and rotation angle in the treatment of posterior semicircular canal benign paroxysmal positional vertigo (PC-BPPV).

METHODS

We enrolled 344 patients with unilateral PC-BPPV. Of these, 167 patients in the simple-step maneuver (SSM) group were accelerated twice and rotated 120° per step, whereas 177 patients in the multi-step maneuver (MSM) group were accelerated 4 times and rotated 60° per step. Dix-Hallpike (DH) tests were performed to categorize the treatment outcome as follows: 'symptom free' if the result was negative, 'symptom persistent' if the result remained positive after performing the maneuver 3 times or 'canal conversion' if horizontal nystagmus was evoked.

RESULTS

Of the patients in the SSM and MSM groups, 78.4 and 91.5% became symptom free, respectively, while canal conversion occurred in 13.8 and 5.1%, respectively (p = 0.003, χ(2) test). The success rate after performing the maneuver once was 57.1% in the MSM and 32.3% in the SSM symptom-free patients (p = 0.001, χ(2) test). One month after the treatment, 22.0 and 9.6% of the SSM and MSM patients had symptom relapse, respectively (p = 0.007, χ(2) test).

CONCLUSIONS

More accelerations and a smaller rotation angle improved the effectiveness and efficiency of the repositioning maneuvers and reduced canal conversion.