Does cervical range of motion affect the outcomes of canalith repositioning procedures for posterior canal benign positional paroxysmal vertigo?

Purpose: Canalith repositioning procedure (CRP) for posterior canal benign positional paroxysmal vertigo (BPPV), also known as Epley maneuver, is a common procedure for the treatment of BPPV. This maneuver entails flexion, extension and rotation of the patient's neck. This study aims to investigate the impact of cervical range of motion (C-ROM) on CRP efficacy. Materials and methods: The study included 47 patients with posterior canal BPPV treated by CRP. The procedure was considered successful if vertigo and nystagmus disappeared at the post-treatment evaluation. If CRP resulted ineffective, it was repeated up to three times per session. C-ROM was measured at BPPV diagnosis before treatment. Patients were followed up for 30 days. Results: The first CRP was successful in 29 patients (61.7%), while it was ineffective in 18 patients (38.3%) requiring multiple repositioning maneuvers. Patients who needed two or more CRP showed lower C-ROM in extension (p = .003) and flexion (p = .042), and earlier recurrences (p = .006). Univariate regression analysis showed that lower cervical extension was significantly associated with the failure of the first CRP (OR: 0.899, 95% CI 0.831–0.973, p = .008). Conclusions: Our data suggest that a reduced C-ROM can require multiple CRPs to successfully treat BPPV and increase the risk of early recurrences