Department of Otorhinolaryngology, Head and Neck Surgery, Inselspital, University Hospital Bern and University of Bern, Bern, Switzerland.
Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Eur J Neurol. 2021 Aug;28(8):2614-2621. doi: 10.1111/ene.14909. Epub 2021 Jun 7.
A peripheral spontaneous nystagmus (SN) is typically enhanced or revealed by removing fixation. Conversely, failure of fixation suppression of SN is usually a sign of a central disorder. Based on Luebke and Robinson (Vision Res 1988, vol. 28 (8), pp. 941-946), who suggested that the normal fixation mechanism is disengaged during pursuit, it is hypothesized that vertical tracking in the light would bring out or enhance a horizontal SN.
Eighteen patients with acute vestibular neuritis were studied. Eye movements were recorded using video-oculography at straight-ahead gaze with and without visual fixation, and during smooth pursuit. The slow-phase velocity and the fixation suppression indices of nystagmus (relative to SN in darkness) were compared in each condition.
During vertical tracking, the slow-phase velocity of horizontal SN with eyes near straight-ahead gaze was significantly higher (median 2.7°/s) than under static visual fixation (median 1.2°/s). Likewise, the fixation index was significantly higher (worse suppression) during pursuit (median 48%) than during fixation (median 26%). A release of SN was also suggested during horizontal pursuit, if one assumes superposition of SN on a normal and symmetrical pursuit capability.
外周性自发性眼球震颤（SN）通常在去除固视时增强或显现。相反，SN 的固视抑制失败通常是中枢性疾病的标志。基于 Luebke 和 Robinson（1988 年视觉研究，第 28 卷（8），第 941-946 页）的研究，他们提出正常的固视机制在追踪过程中被解除，因此假设在光线下进行垂直跟踪会引出或增强水平性 SN。
研究了 18 例急性前庭神经炎患者。使用视频眼动描记术在直视和视觉固视时以及在平滑追踪时记录眼球运动。在每种情况下，比较了眼震的慢相速度和固视抑制指数（相对于暗室中的 SN）。
在垂直跟踪时，眼接近直视位时水平性 SN 的慢相速度（中位数 2.7°/s）明显高于静态视觉固视时（中位数 1.2°/s）。同样，在追踪时（中位数 48%）的固视指数明显高于在固视时（中位数 26%）。如果假设 SN 叠加在正常和对称的追踪能力上，那么在水平追踪时也可能出现 SN 释放。
