Abstract：
OBJECTIVE: The objective of this study was to assess the clinical significance of the Bow and Lean Test (BLT) for the diagnosis of different variants of vertical canal Benign Paroxysmal Positional Vertigo (BPPV). BLT is commonly used for diagnoses of lateral semicircular canal (LSC) BPPV. However, vertical nystagmus in the BLT may indicate the presence of other variants such as PSC-BPPV.
METHODS: 567 patients with vertical canal BPPV were recruited. Patients with anterior semicircular canal (ASC) or PSC-BPPV were weekly examined until the negativization of BPPV. Nystagmus characteristics during BLT were analyzed.
RESULTS: Of 567 patients with vertical canal BPPV, 1.4% had ASC-BPPV. BLT was positive in 155 patients, showing patterns like down-beating nystagmus in bowing and no nystagmus in leaning (15.52% of patients), and down-beating in bowing and up-beating in leaning (6.17%), which was predominantly present in PSC-canalolithiasis. Statistically significant differences were observed in the direction of nystagmus provoked by BLT in PSC-BPPV subtypes. No significant differences were found in nystagmus latency or duration during BLT positions. Among BPPV subtypes, there was a significant difference in nystagmus duration and latency, especially between cupulolithiasis and other variants. BLT\'s sensitivity was 0.93 in bowing and 1 in a leaning position, while specificity was 0.93 and 0.82 respectively.
CONCLUSIONS: Beyond the LSC, the BLT has expanded to other variants. However, study results differ likely due to variations in patient characteristics and test execution. Currently, no specific features for ASC have been found to differentiate it from PSC-BPPV limiting the test\'s use for this variant.
METHODS: 3, according to Oxford Center for Evidence-Based Medicine Laryngoscope, 134:2405-2410, 2024.
METHODS: 567 patients with vertical canal BPPV were recruited. Patients with anterior semicircular canal (ASC) or PSC-BPPV were weekly examined until the negativization of BPPV. Nystagmus characteristics during BLT were analyzed.
RESULTS: Of 567 patients with vertical canal BPPV, 1.4% had ASC-BPPV. BLT was positive in 155 patients, showing patterns like down-beating nystagmus in bowing and no nystagmus in leaning (15.52% of patients), and down-beating in bowing and up-beating in leaning (6.17%), which was predominantly present in PSC-canalolithiasis. Statistically significant differences were observed in the direction of nystagmus provoked by BLT in PSC-BPPV subtypes. No significant differences were found in nystagmus latency or duration during BLT positions. Among BPPV subtypes, there was a significant difference in nystagmus duration and latency, especially between cupulolithiasis and other variants. BLT\'s sensitivity was 0.93 in bowing and 1 in a leaning position, while specificity was 0.93 and 0.82 respectively.
CONCLUSIONS: Beyond the LSC, the BLT has expanded to other variants. However, study results differ likely due to variations in patient characteristics and test execution. Currently, no specific features for ASC have been found to differentiate it from PSC-BPPV limiting the test\'s use for this variant.
METHODS: 3, according to Oxford Center for Evidence-Based Medicine Laryngoscope, 134:2405-2410, 2024.
摘要：
目的：本研究的目的是评估弓和瘦检验（BLT）在诊断垂直管良性阵发性位置性眩晕（BPPV）的不同变体中的临床意义。BLT通常用于诊断外侧半规管（LSC）BPPV。然而,BLT中的垂直眼震可能表明存在其他变体，例如PSC-BPPV。
方法：纳入567例垂直管BPPV患者。对前半规管（ASC）或PSC-BPPV的患者进行每周检查，直到BPPV阴性为止。分析了BLT期间的眼球震颤特征。
结果：在567例垂直管BPPV患者中，1.4%有ASC-BPPV。155例患者BLT阳性,在鞠躬时表现出向下跳动的眼球震颤，在倾斜时没有眼球震颤（15.52％的患者），鞠躬下降，倾斜上升(6.17%)，主要存在于PSC-泪小管结石中。在PSC-BPPV亚型中，BLT引起的眼球震颤方向存在统计学上的显着差异。在BLT位置期间，眼球震颤的潜伏期或持续时间没有发现显着差异。在BPPV亚型中，眼球震颤持续时间和潜伏期有显著差异，尤其是在铜石症和其他变种之间。BLT的灵敏度在弯曲时是0.93，在倾斜位置是1，而特异性分别为0.93和0.82。
结论：超越LSC，BLT已扩展到其他变体。然而,研究结果可能由于患者特征和测试执行的差异而不同.目前,没有发现ASC的特定功能可以将其与PSC-BPPV区分开，从而限制了该变体的测试用途。
方法：3级，根据牛津循证医学中心喉镜，2023年。
方法：纳入567例垂直管BPPV患者。对前半规管（ASC）或PSC-BPPV的患者进行每周检查，直到BPPV阴性为止。分析了BLT期间的眼球震颤特征。
结果：在567例垂直管BPPV患者中，1.4%有ASC-BPPV。155例患者BLT阳性,在鞠躬时表现出向下跳动的眼球震颤，在倾斜时没有眼球震颤（15.52％的患者），鞠躬下降，倾斜上升(6.17%)，主要存在于PSC-泪小管结石中。在PSC-BPPV亚型中，BLT引起的眼球震颤方向存在统计学上的显着差异。在BLT位置期间，眼球震颤的潜伏期或持续时间没有发现显着差异。在BPPV亚型中，眼球震颤持续时间和潜伏期有显著差异，尤其是在铜石症和其他变种之间。BLT的灵敏度在弯曲时是0.93，在倾斜位置是1，而特异性分别为0.93和0.82。
结论：超越LSC，BLT已扩展到其他变体。然而,研究结果可能由于患者特征和测试执行的差异而不同.目前,没有发现ASC的特定功能可以将其与PSC-BPPV区分开，从而限制了该变体的测试用途。
方法：3级，根据牛津循证医学中心喉镜，2023年。
