Abstract
IMPORTANCE: Head-shaking and mastoid oscillation maneuvers effectively treat cupulolithiasis of horizontal canal benign paroxysmal positional vertigo. However, to date there are no validated treatments for cupulolithiasis of posterior canal benign paroxysmal positional vertigo (PC-BPPV-cu). OBJECTIVE: To determine the immediate and short-term therapeutic efficacy of head-shaking and mastoid oscillation maneuvers in PC-BPPV-cu. DESIGN, SETTING, AND PARTICIPANTS: This double-blind randomized clinical trial was conducted at 6 referral-based university hospitals in South Korea between November 1, 2019, and April 30, 2023. The inclusion criteria consisted of (1) repetitive episodes of positional vertigo or dizziness; (2) positional nystagmus beating torsionally with the upper pole of the eye to the lower ear and vertically upward (to the forehead) and lasting longer than 1 minute, which was evoked by Dix-Hallpike or half Dix-Hallpike maneuver; and (3) absence of accompanying neurologic symptoms or signs suggesting central nervous system disorders. Patients were excluded who declined to participate or had cervical spine problems, multicanal BPPV, or cognitive dysfunction. INTERVENTIONS: Patients were randomly assigned to the head-shaking, mastoid oscillation, or sham maneuver groups. After a maximum of 2 trials of each maneuver, therapeutic response was assessed within 30 minutes and the following day. MAIN OUTCOMES AND MEASURES: The primary outcome was the short-term resolution rate of positional vertigo and nystagmus the following day. The secondary outcome was the immediate efficacy of 2 trials of each maneuver within 30 minutes. RESULTS: A total of 159 patients were included in the analysis (108 [67.9%] women; mean [SD] age, 65.4 [10.5] years). Fifty-three participants were randomized to the head-shaking group (mean [SD] age, 64.0 [11.2] years; 33 [62.3%] women), 53 to the mastoid oscillation group (mean [SD], age, 66.5 [11.1] years; 41 [77.4%] women), and 53 to the control group (mean [SD] age, 65.6 [9.2] years; 34 [64.2%] women). A total of 142 patients (89.3%) completed the assessment the following day. In the intention-to-treat analysis, 20 patients in the head-shaking group (37.7%), 14 in the mastoid oscillation group (26.4%), and 7 in the control group (13.2%) showed the resolution of vertigo and nystagmus the following day (χ2 = 8.40; odds ratio, 2.86; 95% CI, 1.32-6.18; P = .004; α = .0167). For the secondary outcome (the immediate effectiveness of 2 trials of each maneuver compared with sham within 30 minutes), no significant difference was detected (6 of 53 [11.3%] vs 4 of 53 [7.5%] vs 2 of 53 [3.8%]; P = .34; α = .05). CONCLUSIONS AND RELEVANCE: In this randomized clinical trial, the head-shaking maneuver was effective in the treatment of PC-BPPV-cu. TRIAL REGISTRATION: CRIS clinical trial registration: KCT0004756.