Potential Risk Factors Affecting Repeated Canalith Repositioning Procedures in Benign Paroxysmal Positional Vertigo.

OBJECTIVE: To define the risk factors and adverse effects associated with repeated canalith repositioning procedures (CRPs).

STUDY DESIGN: A case series featuring chart review.

SETTING: An academic university hospital.

PATIENTS: We retrospectively reviewed 1900 patients (average age, 54.9 years; range, 11-88 years) diagnosed with benign paroxysmal positional vertigo (BPPV). All underwent repeated CRPs. We recorded clinical features including age, gender, BPPV cause (idiopathic or secondary), symptom duration, the canal involved, the number of sessions of CRP, recurrence, follow-up duration, and complications. We compared these factors using Pearson's chi-squared test and multiple linear regression analysis with dummy variables.

INTERVENTIONS: BPPV was diagnosed based on the results of the head roll and Dix-Hallpike tests.

RESULTS: The overall BPPV resolution rate for patients treated with repeated CRPs was 96.4%. The risk factors for the need for multiple CRPs in BPPV were the duration of vertigo before treatment (β = 0.326, p < 0.001), the type of canal involved (β = 0.130, p < 0.001), and age (β = 0.040, p = 0.040). The explanatory power of the regression model attained 46.0% (F = 172.510, p < 0.001). The failure rate of repeated CRPs was 3.6% and complications included canal conversion (3.1%), nausea (46.4%), vomiting (4.9%), head heaviness (50.8%), imbalance (31.9%), and hypotension or palpitations (8.6%). However, almost all patients recovered.

CONCLUSION: The risk factors associated with the need for Multiple CRPs were as follows: longer duration of vertigo before treatment, bilateral or multiple canal involved, and age >50 years.