RESUMO
OBJECTIVES: The Epley maneuver (EM) shows immediate effect, wherein disappearance of positional nystagmus occurs soon after the EM. Our previous study showed that setting interval times during the EM reduced the immediate effect. The purpose of this study is to identify the head position for which interval time reduces the immediate effect. METHODS: Fifty-one patients with posterior canal type of benign paroxysmal positional vertigo (BPPV) were randomly assigned to the following three groups: 10 min interval time set at the first head position of the EM in group A, at the third head position in group B, and at the fourth head position in group C. The primary outcome measure (POï¼) was the ratio of maximum slow-phase eye velocity of positional nystagmus soon after the EM, compared with that measured before the EM. A large ratio value indicates a poor immediate effect of the EM. RESULTS: The POï¼ in group A (0.07) was smallest (B: 0.36, C: 0.49) (p < 0.001). DISCUSSION: The interval times at the third and fourth head positions reduced the immediate effect of the EM. Our previous study showed that the effect of BPPV fatigue is continued by maintaining the first head position of the EM. BPPV fatigue constitutes fatigability of positional nystagmus with repeated performance of the Dix-Hallpike test. Our findings may be interpreted in accordance with the theory that the immediate effect of the EM is BPPV fatigue itself, because we observed that the effect of BPPV fatigue is strongest in group A.
RESUMO
Background and objectives: Patients with benign paroxysmal positional vertigo of the posterior canal (pc-BPPV) exhibit BPPV fatigue, where the positional nystagmus diminishes with the repeated performance of the Dix-Hallpike test (DHt). BPPV fatigue is thought to be caused by the disintegration of lumps of otoconial debris into smaller parts and can eliminate positional nystagmus within a few minutes [similar to the immediate effect of the Epley maneuver (EM)]. In this study, we aimed to show the non-inferiority of the repeated DHt to the EM for eliminating positional nystagmus after 1 week. Methods: This multicenter, randomized controlled clinical trial was designed based on the CONSORT 2010 guidelines. Patients who had pc-BPPV were recruited and randomly allocated to Group A or Group B. Patients in Group A were treated using the EM, and patients in Group B were treated using repeated DHt. For both groups, head movements were repeated until the positional nystagmus had been eliminated (a maximum of three repetitions). After 1 week, the patients were examined to determine whether the positional nystagmus was still present. The groups were compared in terms of the percentage of patients whose positional nystagmus had been eliminated, with the non-inferiority margin set at 15%. Results: Data for a total of 180 patients were analyzed (90 patients per group). Positional nystagmus had been eliminated in 50.0% of the patients in Group A compared with 47.8% in Group B. The upper limit of the 95% confidence interval for the difference was 14.5%, which was lower than the non-inferiority margin. Discussion: This study showed the non-inferiority of repeated DHt to the EM for eliminating positional nystagmus after 1 week in patients with pc-BPPV and that even the disintegration of otoconial debris alone has a therapeutic effect for pc-BPPV. Disintegrated otoconial debris disappears from the posterior canal because it can be dissolved in the endolymph or returned to the vestibule via activities of daily living. Classification of evidence: This study provides Class II evidence of the non-inferiority of repeated DHt to the EM for eliminating positional nystagmus after 1 week. Registration number: UMIN000016421.