Stroke Prediction Based on the Spontaneous Nystagmus Suppression Test in Dizzy Patients

Abstract

ObjectiveFailure 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.MethodsPatients with AVS were screened and recruited (convenience sample) as part of a prospective cross-sectional study in the Emergency Department between 2015-2020. All patients received neuroimaging which served as a reference standard. We recorded fixation suppression with video-oculography (VOG) for straight, right and left gaze. The ocular fixation index (OFI) and the spontaneous nystagmus slow velocity reduction was calculated.ResultsWe screened 1646 dizzy patients in the emergency department and tested for spontaneous nystagmus in 148 included AVS patients. 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 AVS patients, in 40% of patients with vestibular neuritis and in 62.5% of vestibular strokes. OFI scores had no predictive value for detecting strokes, however, a nystagmus reduction of less than 2deg/s showed a high accuracy of 76.9% (CI 0.59-0.89) with a sensitivity of 62.2% and specificity of 84.8% in detecting strokes..ConclusionsThe 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 still predicts accurately vestibular strokes provided that eye movements are recorded with VOG.Classification of EvidenceThis study provides Class II evidence that in patients with an acute vestibular syndrome, decreased fixation suppression recorded with VOG occurred more often in stroke (76.9%) than in vestibular neuritis (37.8%).

Automated alternate cover test for ‘HINTS’ assessment: a validation study

“…It consists of a battery of three tests, the head impulse test, the observation of a Nystagmus and the test of Skew [23]. Since VOG is already used for head impulse recordings [24] and nystagmus detection in the ED, [25] we suggest to measure skew deviations with the same VOG equipment as well. Such an approach would not only allow an examiner-independent diagnostic test at the point-of-care, but it would also provide a quantification and automated assessment of vertical skew in the future [26].…”

Bruns' nystagmus revisited: A sign of stroke in patients with the acute vestibular syndrome

“…In this prospective, cross‐sectional study, data was collected in the ED during daylight hours between 07/2015 and 04/2020, which was part of a larger study (DETECT – Dizziness Evaluation Tool for Emergent Clinical Triage). Data from a large subset of this patient cohort (12/12 strokes and 32/35 vestibular neuritis) have been presented in a prior publication investigating the nystagmus suppression test [2].…”

“…The slow‐phase velocity (SPV), frequency (beats per second), and direction of eye drift of GEN can be quantified using mobile eye tracking devices (Video‐oculography, VOG). Nystagmus can often be suppressed in light and a quantitative suppression test recorded with VOG helps to differentiate central from peripheral causes of vertigo [2, 3]. However, the nystagmus suppression test does not consider other characteristics of nystagmus and has not become a routine part of the ‘HINTS’ testing battery (Head impulse – Nystagmus – Test of skew) [4].…”

“…VOG helps to differentiate central from peripheral causes of vertigo [2,3]. However, the nystagmus suppression test does not consider other characteristics of nystagmus and has not become a routine part of the 'HINTS' testing battery (Head impulse -Nystagmus -Test of skew) [4].…”

Impaired fixation suppression of horizontal vestibular nystagmus during smooth pursuit: pathophysiology and clinical implications

“…Fixation suppression of nystagmus is a hallmark feature of a peripheral vestibular nystagmus (the "Romberg sign" of the vestibulo-ocular reflex) and, if not present, points to a central lesion causing the nystagmus [19] Whilst fixation suppression of a SN is not a perfect discriminator between a central and peripheral lesion, since some patients with central lesions can show fixation suppression [16,17,23] it is nevertheless useful in developing algorithms to localize lesions in patients with nystagmus. What is proposed here is that looking for a change in nystagmus during pursuit, especially horizontal nystagmus during vertical pursuit, complements other ways to reveal an effect of fixation on a SN without putting patients in the dark or using a Frenzel lens, for example, which are not always readily available.…”