Analysis of related factors of recurrence in horizontal semicircular canal benign paroxysmal positional vertigo: a pilot study.

Background: Whether the abnormal caloric test (C-test) affects recurrence rate in horizontal semicircular canal benign paroxysmal positional vertigo (HSC-BPPV) with residual dizziness (RD) is not clear. Objectives: 1) Analyze the association of the cycles of canalith repositioning procedure (CRP), C-test and RD after CRP and 2) determine which affects the recurrence rate in idiopathic HSC-BPPV. Materials and methods: Eighty-four patients with HSC-BPPV (canal type) were included in this work. The cycles of CRP, C-test, the RD after CRP and HSC-BPPV recurrence rate were recorded. Depending on the times of CRP and patients who presented dizziness after treatment, patients were divided into four groups, the relationship between abnormal C-test and RD was analyzed. The outcomes of recurrence rate were compared between groups, respectively. Results: (1) The abnormal C-test prevalence among the HSC-BPPV patients with RD was 36% while in no RD group was 14.7%. The difference was statistically significant ( p  = .045). (2) The recurrence rate was 11.8% in no RD group but in RD group the rate was higher (32%, p  = .039). When patients combined with abnormal C-test, the recurrence rate was significantly higher (77.8% vs. 20%) ( p  = .033). Conclusions: A weak correlation between RD and abnormal C-test is noted. Presence of RD and abnormal C-test in patients with HSC-BPPV predicts a higher recurrence rate.