Department of Otolaryngology, Head and Neck Surgery, Queen Elizabeth University Hospital, Glasgow, Scotland, UK.
J Laryngol Otol. 2023 Apr;137(4):398-403. doi: 10.1017/S0022215122001153. Epub 2022 May 16.
Abnormal gains in six-canal video head impulse test are attributed to semi-circular canal deficits. However, as video head impulse test responses are linked to the vestibulo-ocular reflex, it was hypothesised that abnormal gains can be caused by vestibulo-ocular reflex pathway deficits.
This study compared video head impulse test gains in 20 patients with superior semi-circular canal dehiscence (labyrinthine cause) and 20 side- and gender-matched patients with vestibular schwannomas (retrolabyrinthine cause), and investigated correlations between them (Mann-Kendall trend test).
Vestibular schwannoma but not superior semi-circular canal dehiscence was significantly associated with abnormal lateral (odds ratio = 9.00 (95 per cent confidence interval = 1.638-49.44), = 0.011) and posterior (odds ratio = 9.00 (95 per cent confidence interval = 2.151-37.659), = 0.003) canal status. In vestibular schwannoma patients, there was a statistically significant degree of dependence between all ipsilesional canal video head impulse test gains; such dependence was not observed in superior semi-circular canal dehiscence.
Vestibulo-ocular reflex gains differ in patients with labyrinthine and retrolabyrinthine disease; this suggests that abnormal gains can indicate deficits not only in the semi-circular canals but also elsewhere along the vestibulo-ocular reflex pathway.
六管视频头脉冲试验的异常增益归因于半规管缺陷。然而，由于视频头脉冲试验的反应与前庭眼反射有关，因此假设异常增益可能是由前庭眼反射通路缺陷引起的。
本研究比较了 20 例上半规管裂（迷路原因）和 20 例性别和年龄匹配的前庭神经鞘瘤（迷路后原因）患者的视频头脉冲试验增益，并对它们之间的相关性进行了研究（Mann-Kendall 趋势检验）。
前庭神经鞘瘤而不是上半规管裂与异常的外侧（优势比=9.00（95%置信区间=1.638-49.44），=0.011）和后侧（优势比=9.00（95%置信区间=2.151-37.659），=0.003）管状态显著相关。在前庭神经鞘瘤患者中，所有同侧管视频头脉冲试验增益之间存在统计学上显著的依赖性；在上半规管裂患者中没有观察到这种依赖性。
迷路性和迷路后疾病患者的前庭眼反射增益不同；这表明异常增益不仅可以表明半规管缺陷，还可以表明前庭眼反射通路的其他部位缺陷。
