Negative Impact of Vestibular Suppressant Drugs on Provocative Positional Tests of BPPV: A Study from the Western Part of India

AIMS: To study the impact of vestibular suppressant drugs (VSD) on provocative positional tests (PPT) in patients with benign paroxysmal positional vertigo (BPPV). SETTINGS AND DESIGN: A prospective case-control observational study. MATERIALS AND METHODS: Patients with a history suggestive of BPPV were tested for PPT. Patients with vertiginous symptoms and with nystagmus on PPT were classified as objective BPPV (O-BPPV, control group), while those without nystagmus with no alternate diagnosis were classified as subjective BPPV (S-BPPV, case group). Details of VSD treatment were noted in all the patients. In both groups, patients were instructed to discontinue VSD and were further assigned as the VSD and non-VSD subgroups. Patients were followed for 2 months with PPT every week. PPT positive patients were treated by vestibular rehabilitation maneuvers. STATISTICS: Student t-test with two-tailed, unpaired, was used for continuous scale and Chi-square test for categorical differences between the two groups. RESULTS: 295 consecutive BPPV patients were enrolled in the study, 55 in the S-BPPV group and 240 in the O-BPPV group. Significantly higher proportion of patients in the S-BPPV group were on VSD at presentation, 80.00% vs. 53.75% (OR 2.52; 95% CI: 1.30–4.86), P = 0.006. In an unadjusted analysis of the S-BPPV group following discontinuation of VSD, PPT became positive in 79.54% of patients as compared to 18.19% in the non-VSD group (OR 35.0; 95% CI: 6.2–197.3), P < 0.001. CONCLUSION: A higher proportion of S-BPPV patients were receiving VSD in comparison to O-BPPV at the initial visit. The PPT converted positive four times higher after ceasing the VSD in S-BPPV patients. STUDY DESIGN: Prospective case-control observational study.