From the Department of Otorhinolaryngology, Head and Neck Surgery (G.M., T.W., E.Z., A.K., M.M., M.D.C.), University Institute of Diagnostic and Interventional Neuroradiology (F.W.), Department of Emergency Medicine (T.C.S.), and Department of Neurology (H.K., R.K.), Inselspital, University Hospital Bern and University of Bern, Switzerland.
Neurology. 2021 Jul 6;97(1):e42-e51. doi: 10.1212/WNL.0000000000012176. Epub 2021 May 13.
Failure of fixation suppression of spontaneous nystagmus is sometimes seen in patients with vestibular strokes involving the cerebellum or brainstem; however, the accuracy of this test for the discrimination between peripheral and central causes in patients with an acute vestibular syndrome (AVS) is unknown.
Patients with AVS were screened and recruited (convenience sample) as part of a prospective cross-sectional study in the emergency department between 2015 and 2020. All patients received neuroimaging, which served as a reference standard. We recorded fixation suppression with video-oculography (VOG) for forward, right, and left gaze. The ocular fixation index (OFI) and the spontaneous nystagmus slow velocity reduction was calculated.
We screened 1,646 patients reporting dizziness in the emergency department and tested for spontaneous nystagmus in 148 patients with AVS. We analyzed 56 patients with a diagnosed acute unilateral vestibulopathy (vestibular neuritis) and 28 patients with a confirmed stroke. There was a complete nystagmus fixation suppression in 49.5% of patients with AVS, in 40% of patients with vestibular neuritis, and in 62.5% of patients with vestibular strokes. OFI scores had no predictive value for detecting strokes; however, a nystagmus reduction of less than 2 °/s showed a high accuracy of 76.9% (confidence interval 0.59-0.89) with a sensitivity of 62.2% and specificity of 84.8% in detecting strokes.
The presence of fixation suppression does not rule out a central lesion. The magnitude of suppression was lower compared to patients with vestibular neuritis. The nystagmus suppression test predicts vestibular strokes accurately provided that eye movements are recorded with VOG.
This study provides Class II evidence that in patients with an AVS, decreased fixation suppression recorded with VOG occurred more often in stroke (76.9%) than in vestibular neuritis (37.8%).
在小脑或脑干参与的前庭卒中患者中，自发性眼震的固视抑制失败有时会出现；然而，在急性前庭综合征（AVS）患者中，该测试对鉴别外周和中枢病因的准确性尚不清楚。
在 2015 年至 2020 年期间，作为一项前瞻性横断面研究的一部分，在急诊科对 AVS 患者进行了筛选和招募（方便样本）。所有患者均接受神经影像学检查，作为参考标准。我们使用视频眼震图（VOG）记录了向前、向右和向左凝视时的固视抑制。计算眼固视指数（OFI）和自发性眼震慢相速度降低。
我们在急诊科筛选了 1646 例自述头晕的患者，并对 148 例 AVS 患者进行了自发性眼震测试。我们分析了 56 例确诊的急性单侧前庭病（前庭神经炎）和 28 例确诊的卒中患者。49.5%的 AVS 患者完全抑制了眼震，40%的前庭神经炎患者和 62.5%的前庭卒中患者抑制了眼震。OFI 评分对检测卒中没有预测价值；然而，眼震减少小于 2°/s 时，对检测卒中具有 76.9%（置信区间 0.59-0.89）的高准确率，敏感性为 62.2%，特异性为 84.8%。
固视抑制的存在并不能排除中枢病变。与前庭神经炎患者相比，抑制程度较低。如果使用 VOG 记录眼动，眼震抑制测试可以准确预测前庭卒中。
本研究提供了 II 级证据，即在 AVS 患者中，与前庭神经炎（37.8%）相比，VOG 记录的固视抑制减少更常见于卒中（76.9%）。
