Department of Otorhinolaryngology, Head and Neck Surgery, Inselspital, University Hospital Bern and University of Bern, Bern, Switzerland.
J Int Adv Otol. 2024 May;20(3):241-246. doi: 10.5152/iao.2024.231249.
Assessment of nystagmus fixation suppression can be used as an additional diagnostic tool for patients with an acute vestibular syndrome to distinguish between a central or peripheral cause. We investigated the ability of physicians to detect fixation suppression using a nystagmus simulation model.
We used a nystagmus simulator to measure the accuracy of the nystagmus fixation suppression test. Fixation suppression was assessed randomly in 6170 trials by 20 otorhinolaryngologists and neurologists, segregated into 2 groups based on their neurootological experience, a beginner and an experienced group. The simulator presented random nystagmus slow velocity (SPV) reductions and presented 3 conditions with either changed nystagmus frequency, amplitude, or both.
The cutoff for the discernment of fixation suppression ranged from 1.2 to 14°/s nystagmus velocity difference. The more intense the baseline nystagmus was, the more difficult was the detection of fixation suppression. There was not significant difference (P >.05) in the cutoff values in the experts group compared to the novices for all 3 different conditions. Both, novices and experts, detected frequency changes easier than differences of the nystagmus amplitude. Test sensitivity was very low (19%-65%) for discernment of small nystagmus velocity differences of <2°/s by experts.
In our study, there was no difference between experts and novices in detection of nystagmus suppression by visual fixation. The examiners could only detect large suppression effects at low-intensity baseline nystagmus. Overall, the sensitivity and accuracy of a clinical fixation suppression test is low and the assistance with a video-oculography device is highly recommended.
眼球震颤固视抑制评估可作为急性前庭综合征患者的附加诊断工具，用于区分中枢或外周病因。我们研究了医生使用眼球震颤模拟模型检测固视抑制的能力。
我们使用眼球震颤模拟器来测量眼球震颤固视抑制测试的准确性。由 20 名耳鼻喉科医生和神经科医生随机评估 6170 次试验中的固视抑制，根据他们的神经耳科学经验分为初学者和经验丰富者两组。模拟器呈现随机的眼球震颤慢相速度（SPV）降低，并呈现 3 种条件，分别改变眼球震颤频率、振幅或两者。
辨别固视抑制的截止值范围为 1.2 至 14°/s 眼球震颤速度差。基础眼球震颤越强，检测固视抑制越困难。在所有 3 种不同条件下，专家组与新手组的截止值均无显著差异（P>.05）。新手和专家都更容易检测到眼球震颤频率的变化，而不是振幅的差异。对于 <2°/s 的小眼球震颤速度差异，专家的辨别能力非常低（19%-65%）。
在我们的研究中，专家和新手在通过视觉固视检测眼球震颤抑制方面没有差异。检查者只能在低强度基础眼球震颤时检测到较大的抑制效果。总体而言，临床固视抑制测试的敏感性和准确性较低，强烈推荐使用视频眼动描记法设备进行辅助。
