scholarly journals Nystagmus goggles: how to use them, what you find and what it means

2020 ◽  
Vol 20 (6) ◽  
pp. 446-450
Author(s):  
G Michael Halmagyi ◽  
Leigh A McGarvie ◽  
Michael Strupp
Keyword(s):  
Clinical Examination ◽  
Visual Fixation ◽  
Spontaneous Nystagmus ◽  
Fundamental Characteristic ◽  
Vestibular Nystagmus ◽  
Horizontal Nystagmus

A fundamental characteristic of peripheral vestibular nystagmus, in particular horizontal nystagmus, is that it is suppressed by visual fixation. This means that a patient with a vertigo attack of peripheral vestibular origin might have no obvious spontaneous nystagmus on clinical examination. Goggles that reduce or remove visual fixation allow the cliniican to observe nystagmus in this situation. Nystagmus goggles are essential for any clinician dealing with dizzy patients. Here, we discuss why this is so and how easy it is to acquire and use them.

scholarly journals VertiGo – a pilot project in nystagmus detection via webcam

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Sophia Reinhardt ◽  
Joshua Schmidt ◽  
Michael Leuschel ◽  
Christiane Schüle ◽  
Jörg Schipper
Keyword(s):  
Computer Vision ◽  
Clinical Application ◽  
Feasibility Study ◽  
Clinical Examination ◽  
Pilot Project ◽  
Vestibular Nystagmus ◽  
Central Origin ◽  
Recorded Data

AbstractDizziness is one of the most common symptoms in medicine. For differentiation of peripheral or central origin of the vertigo, history and clinical examination with detection of a nystagmus is essential. The aim of this study was to detect horizontal vestibular nystagmus utilizing a webcam. In the feasibility study, caloric induced vestibular nystagmus was recorded with conventional video-nystagmography and webcam. Analysis of recorded data was performed with a developed software which used computer vision techniques. A designed algorithm detected nystagmus existence and their direction. The software was evaluated by an expert-rated video-nystagmography. Webcam-based vestibular nystagmus detection is possible. Currently, a clinical application is not approved. Further software improvements are necessary to increase its accuracy.

scholarly journals 022 Patient-initiated event monitoring for acute vertigo

2019 ◽  
Vol 90 (e7) ◽  
pp. A8.2-A8
Author(s):  
Allison S Young ◽  
Corinna Lechner ◽  
Andrew P Bradshaw ◽  
Hamish G MacDougall ◽  
Deborah A Black ◽  
...  
Keyword(s):  
Spontaneous Nystagmus ◽  
Slow Phase ◽  
Vestibular Disorders ◽  
Positional Nystagmus ◽  
Low Velocity ◽  
Event Monitoring ◽  
Superior Semicircular Canal Dehiscence ◽  
Positional Vertigo ◽  
Horizontal Nystagmus ◽  
Vertical Nystagmus

IntroductionThe diagnosis of vestibular disorders may be facilitated by analysing patient-initiated capture of ictal nystagmus.MethodsAdults with a history of recurrent vertigo were taught to self-record spontaneous and positional-nystagmus at home while symptomatic, using video-goggles. Patients with final diagnoses of disorders presenting with recurrent vertigo were analysed: 121 patients with Ménière’s Disease (MD), Vestibular Migraine (VM), Benign Positional Vertigo (BPV), Episodic Ataxia Type II (EAII), Vestibular Paroxysmia (VP) or Superior Semicircular Canal Dehiscence (SSCD) were included.ResultsOf 43 MD patients, 40 showed high-velocity spontaneous horizontal-nystagmus (median slow-phase velocity (SPV) 39.7 degrees/second (°/s); Twenty-one showed horizontal-nystagmus reversing direction within 12-hours (24 on separate days). In 44 of 67 patients with VM, low velocity spontaneous horizontal (n=28, 4.9°/s), up-beating (n=6, 15.5°/s) or down-beating-nystagmus (n=10, 5.1°/s) was observed; Sixteen showed positional-nystagmus only, and seven had no nystagmus. Spontaneous horizontal-nystagmus with SPV >12.05°/s had a sensitivity and specificity of 95.3% and 82.1% for MD. Nystagmus direction-change within 12-hours was highly specific (95.7%) for MD. Spontaneous vertical-nystagmus was highly specific (93.0%) for VM. In the seven BPV patients, spontaneous-nystagmus was absent or <3°/s, and characteristic paroxysmal positional nystagmus was observed in all cases. Patients with central and MD-related positional vertigo demonstrated persistent nystagmus. Two patients with EAII showed spontaneous vertical nystagmus, one patient with VP showed short bursts of horizontal-torsional nystagmus lasting 5–10s, and one patient with SSCD demonstrated paroxysmal torsional down-beating nystagmus when supine.ConclusionsPatient-initiated vestibular event-monitoring is feasible and could facilitate rapid and accurate diagnosis of episodic vestibular disorders.

Nystagmus characteristics of healthy controls

2020 ◽  
Vol 30 (6) ◽  
pp. 345-352
Author(s):  
Allison S. Young ◽  
Sally M. Rosengren ◽  
Mario D’Souza ◽  
Andrew P. Bradshaw ◽  
Miriam S. Welgampola
Keyword(s):  
Upright Position ◽  
Community Dwelling ◽  
Spontaneous Nystagmus ◽  
Slow Phase ◽  
Healthy Controls ◽  
Positional Nystagmus ◽  
Low Velocity ◽  
Video Oculography ◽  
Significant Difference ◽  
Horizontal Nystagmus

BACKGROUND: Healthy controls exhibit spontaneous and positional nystagmus which needs to be distinguished from pathological nystagmus. OBJECTIVE: Define nystagmus characteristics of healthy controls using portable video-oculography. METHODS: One-hundred and one asymptomatic community-dwelling adults were prospectively recruited. Participants answered questions regarding their audio-vestibular and headache history and were sub-categorized into migraine/non-migraine groups. Portable video-oculography was conducted in the upright, supine, left- and right-lateral positions, using miniature take-home video glasses. RESULTS: Upright position spontaneous nystagmus was found in 30.7% of subjects (slow-phase velocity (SPV)), mean 1.1±2.2 degrees per second (°/s) (range 0.0 – 9.3). Upright position spontaneous nystagmus was horizontal, up-beating or down-beating in 16.7, 7.9 and 5.9% of subjects. Nystagmus in at least one lying position was found in 70.3% of subjects with 56.4% showing nystagmus while supine, and 63.4% in at least one lateral position. While supine, 20.8% of subjects showed up-beating nystagmus, 8.9% showed down-beating, and 26.7% had horizontal nystagmus. In the lateral positions combined, 37.1% displayed horizontal nystagmus on at least one side, while 6.4% showed up-beating, 6.4% showed down-beating. Mean nystagmus SPVs in the supine, right and left lateral positions were 2.2±2.8, 2.7±3.4, and 2.1±3.2°/s. No significant difference was found between migraine and non-migraine groups for nystagmus SPVs, prevalence, vertical vs horizontal fast-phase, or low- vs high-velocity nystagmus (<5 vs > 5°/s). CONCLUSIONS: Healthy controls without a history of spontaneous vertigo show low velocity spontaneous and positional nystagmus, highlighting the importance of interictal nystagmus measures when assessing the acutely symptomatic patient.

Suppression of spontaneous nystagmus during different visual fixation conditions

2011 ◽  
Vol 269 (7) ◽  
pp. 1759-1762 ◽  
Author(s):  
Timo P. Hirvonen ◽  
Martti Juhola ◽  
Heikki Aalto
Keyword(s):  
Visual Fixation ◽  
Spontaneous Nystagmus

scholarly journals Suppressive control of optokinetic and vestibular nystagmus by the primate frontal eye field

2020 ◽  
Vol 124 (3) ◽  
pp. 691-702
Author(s):  
Yoshiko Izawa ◽  
Hisao Suzuki
Keyword(s):  
Electrical Stimulation ◽  
Eye Movements ◽  
Visual Fixation ◽  
Frontal Eye Field ◽  
Vestibular Nystagmus ◽  
Functional Classes ◽  
Eye Field ◽  
Neuronal Assembly

In this study, electrical stimulation in the frontal eye field (FEF) suppressed the quick and slow phases of optokinetic and vestibular nystagmus at an intensity subthreshold for eliciting saccades. Furthermore, the activity of fixation neurons in the FEF was related to the suppression of optokinetic and vestibular nystagmus by visual fixation. This suggests that a common neuronal assembly in the FEF may contribute to the suppressive control of different functional classes of eye movements.

Capturing acute vertigo

Neurology ◽  
2019 ◽  
Vol 92 (24) ◽  
pp. e2743-e2753 ◽  
Author(s):  
Allison S. Young ◽  
Corinna Lechner ◽  
Andrew P. Bradshaw ◽  
Hamish G. MacDougall ◽  
Deborah A. Black ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Spontaneous Nystagmus ◽  
Slow Phase ◽  
Vestibular Disorders ◽  
Positional Nystagmus ◽  
Event Monitoring ◽  
Positional Vertigo ◽  
Horizontal Nystagmus ◽  
Vertical Nystagmus ◽  
Paroxysmal Positional Vertigo

ObjectiveTo facilitate the diagnosis of vestibular disorders by patient-initiated capture of ictal nystagmus.MethodsAdults from an Australian neurology outpatient clinic reporting recurrent vertigo were recruited prospectively and taught to self-record spontaneous and positional nystagmus at home while symptomatic, using miniature video-oculography goggles. Consenting patients with ictal videorecordings and a final unblinded clinical diagnosis of Ménière disease (MD), vestibular migraine (VM), or benign paroxysmal positional vertigo (BPPV) were included.ResultsIctal eye videos of 117 patients were analyzed. Of 43 patients with MD, 40 showed high-velocity spontaneous horizontal nystagmus (median slow-phase velocity [SPV] 39.7°/s; 21 showed horizontal nystagmus reversing direction within 12 hours [24 on separate days]). In 44 of 67 patients with VM, spontaneous horizontal (n = 28, 4.9°/s), upbeating (n = 6, 15.5°/s), or downbeating nystagmus (n = 10, 5.1°/s) was observed; 16 showed positional nystagmus only, and 7 had no nystagmus. Spontaneous horizontal nystagmus with SPV >12.05°/s had a sensitivity and specificity of 95.3% and 82.1% for MD (95% confidence interval [CI] 0.84–0.99, 0.71–0.90). Nystagmus direction change within 12 hours was highly specific (95.7%) for MD (95% CI 0.85–0.99). Spontaneous vertical nystagmus was highly specific (93.0%) for VM (95% CI 0.81–0.99). In the 7 patients with BPPV, spontaneous nystagmus was absent or <3°/s. Lying affected-ear down, patients with BPPV demonstrated paroxysmal positional nystagmus. Median time for peak SPV to halve (T50) was 19.0 seconds. Patients with VM and patients with MD demonstrated persistent positional nystagmus (median T50; 93.1 seconds, 213.2 seconds). T50s <47.3 seconds had a sensitivity and specificity of 100% and 77.8% for BPPV (95% CI 0.54–1.00, 0.64–0.88).ConclusionPatient-initiated vestibular event monitoring is feasible and could facilitate rapid and accurate diagnosis of episodic vestibular disorders.

Analysis of vertebrate eye movements following intravitreal drug injections. II. Spontaneous nystagmus induced by picrotoxin is mediated subcortically

1988 ◽  
Vol 60 (3) ◽  
pp. 1022-1035 ◽  
Author(s):  
M. Ariel ◽  
F. R. Robinson ◽  
A. G. Knapp
Keyword(s):  
Visual Cortex ◽  
Eye Movements ◽  
Visual Stimulation ◽  
Ganglion Cells ◽  
Vestibular Stimulation ◽  
Spontaneous Nystagmus ◽  
Slow Phase ◽  
Directional Information ◽  
Gaba Antagonist ◽  
Horizontal Nystagmus

1. Eye movements were observed following an injection of picrotoxin, a GABA antagonist, into the vitreous of one eye. A spontaneous nystagmus was observed in cats, rabbits, and turtles, even in total darkness, with slow-phase eye movements in the temporal-to-nasal direction for the injected eye. 2. During visual stimulation by a horizontal drifting pattern, injected eyes moved in the temporal-to-nasal direction, irrespective of stimulus direction. In cats, however, the nystagmus was usually slower when the injected eye viewed nasal-to-temporal motion (opposite to the direction of the spontaneous nystagmus). The spontaneous nystagmus could be halted or even reversed by allowing cats to view motion opposite to the direction of the nystagmus with the uninjected eye alone. The nystagmus could not be overridden in this fashion in rabbits or turtles. 3. The nystagmus induced by picrotoxin could also be modified by vestibular stimulation. When cats were placed on their sides, the spontaneous horizontal nystagmus often decreased and spontaneous vertical nystagmus with upward slow phase movements occurred. During sinusoidal horizontal vestibular stimulation, the horizontal nystagmus due to picrotoxin added to the vestibuloocular reflex as a velocity offset in the temporal-to-nasal direction. 4. Following bilateral ablation of the cat visual cortex, picrotoxin's effect became even more pronounced than before the ablation. Therefore, at least some picrotoxin-sensitive cells can use subcortical pathways, perhaps to the accessory optic nuclei. The visual cortex, which also processes directional information, may be able to compensate for changes in retinal processing induced by picrotoxin in intact animals. 5. This study demonstrates the importance of retinal GABA in the control of eye stability. As GABA is known to be responsible for null direction inhibition of directionally sensitive retinal ganglion cells, these results suggest that the output of these cells may be critical for the normal functioning of central optokinetic pathways, even in the absence of visual cortex.

Inhibition of Labyrinthine Nystagmus by Visual Fixation: Effects of Ablation of Visual Cortex and Superior Colliculi

1979 ◽  
Vol 88 (3) ◽  
pp. 419-423
Author(s):  
Emil P. Liebman ◽  
Joseph U. Toglia
Keyword(s):  
Visual Cortex ◽  
Visual System ◽  
Brain Stem ◽  
Light Stimulus ◽  
Visual Fixation ◽  
Vestibular Nystagmus ◽  
Superior Colliculi ◽  
Vestibular Testing ◽  
Significant Change ◽  
The Brain

A study was conducted to destroy two specific areas of the cat's visual system in order to determine if these lesions would affect the visual inhibition of calorically-induced vestibular nystagmus. The occipital visual cortex was removed in eight cats and the superior colliculi were removed bilaterally in nine cats. Postoperative vestibular testing revealed no significant change in the electronystagmography tracings and response to visual fixation. These findings suggest that, in cats, the visual inhibition of labyrinthine nystagmus is not dependent upon the integrity of the visual cortex or superior colliculi. The hypothesis is brought forward that the visual inhibition of the vestibular nystagmus is merely a reflex of the brain stem to light stimulus, mediated via the cerebellum.

Tumor Diagnosis

1982 ◽  
Vol 40 ◽  
pp. 262-265
Author(s):  
Bruce Mackay
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Differential Diagnosis ◽  
Light Microscopy ◽  
Clinical Examination ◽  
Ultrastructural Study ◽  
Diagnostic Procedures ◽  
Specific Diagnosis ◽  
Transmission Electron ◽  
Microscopic Diagnosis

The broadest application of transmission electron microscopy (EM) in diagnostic medicine is the identification of tumors that cannot be classified by routine light microscopy. EM is useful in the evaluation of approximately 10% of human neoplasms, but the extent of its contribution varies considerably. It may provide a specific diagnosis that can not be reached by other means, but in contrast, the information obtained from ultrastructural study of some 10% of tumors does not significantly add to that available from light microscopy. Most cases fall somewhere between these two extremes: EM may correct a light microscopic diagnosis, or serve to narrow a differential diagnosis by excluding some of the possibilities considered by light microscopy. It is particularly important to correlate the EM findings with data from light microscopy, clinical examination, and other diagnostic procedures.

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