[Diagnostic value of RART and LDT in determining the affected semicircular canal for the HSC-BPPV]

Objective:To evaluate the utility of the Rapid Axial Roll Test （RART）, Supine Roll Test （SRT）, and Lying-Down Test （LDT） in determining the affected semicircular canal in cases of horizontal semicircular canal benign paroxysmal positional vertigo （HSC-BPPV）. Methods:A total of 330 patients diagnosed with HSCBPPV from September 2022 to September 2023 were collected and divided into three groups based on the different positional tests received: ①SRT Group, ②LDT+SRT Group, ③RART+SRT Group. The trial was divided into two stages: LDT/RART for patients in the first stage, and SRT for patients in the second stage. The elicitation rate of nystagmus among the three groups was compared to evaluate the accuracy in determining the affected semicircular canal in HSCBPPV. Results:Nystagmus was elicited in 84.55% （279/330） of the patients by positional tests. The elicitation rate of nystagmus in the RART+SRT/LDT group was 94.55% （104/110）, in the LDT+SRT group it was 84.11% （90/107）, and in the SRT group it was 69.91% （79/113）. The differences among the three groups were statistically significant （χ²= 23.88, P<0.001）. In the ② and ③ groups, there was a statistically significant difference in the elicitation rate of nystagmus between stage Ⅰ （patients with LDT or RART） （χ²=43.842, P<0.001）. SRT was performed in the stage Ⅱ, and there was a statistically significant difference in nystagmus extraction rate between the two groups （χ² =4.690, P=0.030）. The difference in the proportion of agreement between stage Ⅰ（LDT or RART） and stageⅡ （SRT） in determining the affected side of the semicircular canal was also statistically significant （χ² =40.502, P<0.001）. For patients with a consistent diagnosis of the affected semicircular canal, the difference in cure rate was not significant （P=0.149）. The Kappa statistic indicated substantial agreement between RART and SRT in terms of eliciting nystagmus （agreement 96.36%, Kappa = 0.730, P<0.001）. Conclusion:RART and SRT show a high degree of agreement regarding the elicitation rate of nystagmus. RART is simple and safe, and it can effectively induce the characteristic nystagmus of HSC-BPPV, accurately identify the responsible semicircular canal and provide a more optimized examination protocol for clinical practice in HSCBPPV.