The objectives of this study is to compare the efficacy between repetition of Epley maneuver and switch to alternate Semont maneuver in treating posterior canal benign paroxysmal positional vertigo (PC-BPPV) that does not respond to the initial Epley maneuver. In the nationwide, seven dizziness clinics of Korea, 506 consecutive patients (303 women, age range 22-87, mean age ± SD = 64 ± 12, median = 61) with idiopathic PC-BPPV were initially treated with a single Epley maneuver. Of those, 144 (28.5%) patients, who did not respond to the therapy, were randomized to the repetition of Epley maneuver (n = 70) or switch to Semont maneuver (n = 74). The therapeutic efficacy was determined within 1 h by a blinded examiner after the trial of each second maneuver. The efficacy did not differ between the repetition of Epley maneuver and switch to Semont maneuver groups (38.6 vs. 27.0%, p = 0.14, Chi-square test). However, the patients with a long duration (p < 0.001, linear regression) and latency (p = 0.01) of the positional nystagmus during Dix-Hallpike maneuver showed a higher rate of the initial and second treatment failures. Either Epley or Semont maneuver may be applied as a second treatment to the patients with PC-BPPV refractory to the initial Epley maneuver. This study provides Class I evidence that repeated Epley and switch to Semont maneuver shows a similar efficacy in treating PC-BPPV that does not respond to the initial Epley maneuver.
Clinical trial registration: NCT01822002.
Keywords: BPPV, benign paroxysmal positional vertigo; Double-blind randomized trial; Epley maneuver; Nystagmus; PC-BPPV, BPPV involving the posterior semicircular canal; Semont maneuver; Treatment outcome; Vertigo; Vestibular.