Abstract P753: Comparison of Calibration vs Non-Calibration Techniques in the Automated Capture of Eye Movement Data: Initial Validation of the Roadie Device for Detecting Posterior Circulation Stroke

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Mohamed Hassan ◽  
Chad Aldridge ◽  
Yan Zhuang ◽  
Timothy L McMurry ◽  
Gustavo Rohde ◽  
...  
Keyword(s):  
Eye Movements ◽  
Eye Tracking ◽  
Smooth Pursuit ◽  
Strong Correlation ◽  
Posterior Circulation ◽  
Screening Tools ◽  
Moderate Correlation ◽  
Posterior Circulation Stroke ◽  
Initial Validation ◽  
Acute Vestibular Syndrome

Background: Posterior circulation stroke (PCS) accounts for ~20% of ischemic strokes. Existing EMS screening tools lack accuracy in the diagnosis of PCS. We aim to develop an automated screening tool to detect abnormal eye movements in patients presenting with PCS. Methods: As an initial step, we built a portable platform called RoADIE (Rolling Apparatus to Detect Impairment of the Eyes), equipped with eye-tracking software to acquire gaze data from patients presenting with PCS, acute vestibular syndrome, and normal controls. We first performed a validation study in 19 healthy controls comparing calibration (C) vs non-calibration (NC) techniques. Eye movements were captured using a standard H-Test exam. The NC condition was performed first for each volunteer to avoid a learning effect. Correlation between C and NC tests was determined using the Spearman coefficient (r). Results: Conjugate gaze (i.e. ability of eyes to track in unison) demonstrated strong correlation along the horizontal [r = 0.976 (C), 0.922 (NC)] and vertical axes [r= 0.866 (C), 0.881(NC)]. Smooth pursuit (i.e. ability of each eye to track moving target) also showed strong correlation in the horizontal plane: right eye [r = 0.945 (C), 0.946 (NC), left eye [r=0.945 (C), 0.943 (NC)]. Vertical tracking showed moderate correlation: right eye [r=0.652 (C), 0.575 (NC), left eye [r=0.678 (C), 0.550 (NC)]. Conclusion: In this initial validation test of a portable eye tracking platform, we demonstrated strong correlation for both conjugate gaze and smooth pursuit in the horizontal axis, and moderate correlation for eye tracking in the vertical axis. Given similar performance in non-calibrated tests, a calibration procedure may not be necessary for future data capture. Next steps will include validation of the eye tracking device in prospective patients presenting with PCS and acute vestibular syndrome. Acknowledgement: Funding support through AHA Innovative Project Award 19IPLOI34760692

scholarly journals Az akut vestibularis szindróma sürgősségi diagnosztikájával szerzett tapasztalatok

2017 ◽  
Vol 158 (51) ◽  
pp. 2029-2040
Author(s):  
T. László Tamás ◽  
Tibor Garai ◽  
István Király ◽  
Andrea Mike ◽  
Csaba Nagy ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Diagnostic Accuracy ◽  
Emergency Room ◽  
Posterior Circulation ◽  
Cranial Computed Tomography ◽  
Lower Sensitivity ◽  
Posterior Circulation Stroke ◽  
Bedside Test ◽  
Imaging Results ◽  
Acute Vestibular Syndrome

Abstract: Introduction and aim: To diagnose acute vestibular syndrome (AVS) in a prospective study by a new bedside test (providing 1A evidence) based on oculomotor analysis and assessment of hearing loss. To assess the frequency of central and peripheral causes of acute vestibular syndrome in the emergency room. To establish the diagnostic accuracy of acute cranial computed tomography as compared to oculomotor analysis done by video oculography goggles and audiometry. Method: Between 1st March 2016 and 1st March 2017 we documented 125 patients (62 women, 63 men, average age 53 years) in the emergency room of the Petz Aladár County Teaching Hospital using the above bedside and instrumental testing. Diagnosis was verified by cranial magnetic resonance imaging. Results: According to the results of the instrumental examination in AVS in 67% we found a peripheral cause and in 33% a central pathology. In 62% isolated posterior circulation stroke manifested itself by isolated vertigo without additional focal signs and the acute cranial computed tomography showed negative results in 96%. The instrumental examination increased diagnostic accuracy by making the diagnosis of isolated inferior semicircular canal vestibular neuritis possible. Conclusions: The new bedside oculomotor test is suitable for the diagnosis of posterior circulation stroke manifesting with isolated vertigo in early cases, when the routine neuroradiologic methods have a lower sensitivity or are not available. Orv Hetil. 2017; 158(51): 2029–2040.

scholarly journals Investigating the Need for Calibration to Track Eye Movements: A Feasibility Study

2021 ◽  
Author(s):  
Mohamed Abul Hassan Ameen ◽  
Chad M. Aldridge ◽  
Yan Zhuang ◽  
Xuwang Yin ◽  
Timothy McMurry ◽  
...  
Keyword(s):  
Eye Movements ◽  
Feasibility Study ◽  
Neurological Diseases ◽  
Calibration Procedure ◽  
Posterior Circulation ◽  
Clinical Context ◽  
Posterior Circulation Stroke ◽  
Difficult Time ◽  
Preliminary Study ◽  
Tracking Technology

Abstract Automated eye tracking technology could enhance diagnosis and treatment for many neurological diseases, including posterior circulation stroke. Much of the current literature focuses on gaze estimation through a form of calibration. Unlike other fields, medicine has a clear need to better track eye symmetry during movement for better detection of abnormal conjugacy, ductions, and vestibulo-ocular function in a variety of neurological diseases. However, patients with neuro-ocular deficits may have a difficult time completing a calibration procedure due to inattention and other associated neurologic deficits. Here, we investigate the need for calibration to measure the symmetry of eye movements in healthy individuals including testing fixations, smooth pursuits, and saccades. The results of this feasibility study suggest that calibration may not be necessary to measure and track binocular eye movements in tandem. The structure or shape which the eyes draw during visual tracking remain intact even without a calibration procedure. The preliminary study suggests that this technology can be deployed without a calibration procedure within this clinical context. Further research is needed to validate these findings in populations with neuro-ophthalmologic disease, including posterior circulation stroke.

scholarly journals HINTS protocole and it’s accuracy to identify posterior circulation stroke: a review

2021 ◽  
Author(s):  
Eduardo Sales Loureiro ◽  
Luna Vasconcelos Felippe ◽  
Ana Luiza Cotta Mourão Guimarães ◽  
Anna Carolina Dockhorn de Menezes Carvalho Costa
Keyword(s):  
Hearing Loss ◽  
Positive Predictive Value ◽  
Predictive Value ◽  
Emergency Departments ◽  
Posterior Circulation ◽  
Clinical Use ◽  
Emergency Physicians ◽  
Practical Application ◽  
Posterior Circulation Stroke ◽  
Acute Vestibular Syndrome

Introduction: The HINTS protocol is important to differentiate peripheral from central vertigo in Acute Vestibular Syndrome (AVS). There are studies that show almost 1/3 of patients have posterior circulation stroke. It is important to investigate why this happens. Objectives: Review the accuracy of HINTS test in the diagnosis of posterior circulation stroke. Methods: Review conducted in PubMed using key words “HINTS AND ACCURACY AND STROKE”. The search found 9 articles, 7 of which were included. Results: Tehrani et al. (2014) studied HINTS’s accuracy when associated with hearing loss, resulting on a bigger accuracy than MRI. Newman- Toker et al. (2013) found that HINTS score was superior than ABCD2 in identifying AVS caused by stroke. From Carmona et al. (2016), HINTS had 100 % sensibility and 94,4% specificity and emphasized ataxia evaluation’s importance, once all patients with central etiology had a grade of ataxia. Krishnan et al. (2019) HINTS had 59,9% Negative Predictive Value (NPV) and 97,2 % Positive Predictive Value (PPV) related to stroke, same PPV was found by Sankalia et al. (2021). Ohle et al. (2020) observed that HINTS done by a neurologist was more accurate than studies that mixed neurologists and emergency physicians. Dmitriew et al. (2021) saw that HINTS was used wrongly in non-specific emergency departments, once only 3,1% patients tested had AVS and 96,9% wrongly tested had false positives. Conclusion: The HINTS is a valuable instrument in the clinical use and the training for better practical application needs incentive in emergency departments.

scholarly journals The role of transcranial Doppler ultrasonography in differential diagnosis of vertigo in the Emergency Department

2019 ◽  
Vol 15 (3) ◽  
Author(s):  
Antonio Siniscalchi ◽  
Giovanni Malferrari
Keyword(s):  
Emergency Department ◽  
Differential Diagnosis ◽  
Transcranial Doppler ◽  
Neurological Diseases ◽  
Low Cost ◽  
Color Doppler ◽  
Subsequent Treatment ◽  
Posterior Circulation ◽  
Posterior Circulation Stroke ◽  
Acute Vestibular Syndrome

Vertigo represents about 4% of access to the Emergency Department (ED). Several conditions, such as general medical illnesses, otovestibular diseases and neurological diseases (including posterior circulation stroke) cause acute vertigo. The incidence of cerebrovascular disease in patients with vertigo in ED varies from 3 to 5%. Although neurosonology studies on acute vestibular syndrome are scarce, the use of transcranial Doppler (TCD) and transcranial color Doppler (TCCD) in the management of vertigo patients has several advantages: it can be performed at the patient's bedside and repeated and, furthermore, its use is low-cost. In an acute stroke, with an experienced doctor, it can help distinguish an ischemic stroke from a hemorrhagic stroke. In acute central vertigo induced by posterior circulation stroke, the TCD or TCCD can be a screening test before angiographic neuroradiological studies for stenosis of vertebral or basal arteries. As a matter of fact, the clinical outcome, particularly in the posterior circulation stroke, is mainly related to a rapid diagnosis and subsequent treatment that will be able to quickly restore the blood flow. In conclusion, TCD and TCCD are useful in the differential diagnosis of vertigo in the ED, although we recognize the indisputable importance of clinical examination as a first step in vertigo management. In the evaluation of patients with acute central vertigo due to suspected posterior circulation stroke, the use of TCD or TCCD can rapidly reveal steno-occlusive disease of the posterior circulation, arterial dissections and give indirect signs of vertebra-basilar insufficiency.

Smooth Pursuit along a Solid Line: A New Variation on the Theme of Efference-Copy-Bound Eye Tracking

Perception ◽  
1993 ◽  
Vol 22 (4) ◽  
pp. 477-482
Author(s):  
Claude Lamontagne ◽  
François J Desjardins ◽  
R T Pivik
Keyword(s):  
Eye Movements ◽  
Eye Tracking ◽  
Smooth Pursuit ◽  
Extreme Case ◽  
Apparent Movement ◽  
Efference Copy ◽  
Continuous Illumination ◽  
Moving Target ◽  
Straight Line ◽  
Theoretical Considerations

Theoretical considerations of the physiology of eye tracking have long implied that the kinematics of smooth pursuit need not parallel those of the pursued target, with pursuit in the absence of a physically moving target as an extreme case. Yet these theoretical implications have been largely ignored, with the consequence that observed kinematic discrepancies between target and pursuit have generally been presented as somewhat surprising, and this view has maintained unnecessary diversity among reported smooth-pursuit phenomena. The case of yet another stimulus-discrepant smooth-pursuit phenomenon is presented and is used to suggest a role which recognized eye-tracking theory might advantageously play in classifying smooth-pursuit phenomena. The new phenomenon, smooth pursuit along a stationary solid straight line under continuous illumination, was demonstrated in a study where eye movements were documented by continuous recordings of the electrooculogram. All twelve subjects were able to initiate smooth pursuit along the line and to maintain it in the absence of any other source of stimulation, and all reported experiencing apparent movement during smooth pursuit. It is suggested that smooth-pursuit phenomena can best be classified in terms of degree of efference-copy dependency.

An Eye Tracking Study on Feigned Schizophrenia

2021 ◽  
Author(s):  
Francesca Ales ◽  
Luciano Giromini ◽  
Lara Warmelink ◽  
Megan Polden ◽  
Thomas Wilcockson ◽  
...  
Keyword(s):  
Data Analysis ◽  
Eye Movements ◽  
Eye Tracking ◽  
Healthy Volunteers ◽  
Full Advantage ◽  
Smooth Pursuit ◽  
Published Data ◽  
Malingering Detection ◽  
Tracking Technology ◽  
Do So

AbstractResearch on malingering detection has not yet taken full advantage of eye tracking technology. In particular, while several studies indicate that patients with schizophrenia behave notably differently from controls on specific oculomotor tasks, no study has yet investigated whether experimental participants instructed to feign could reproduce those behaviors, if coached to do so. Due to the automatic nature of eye movements, we anticipated that eye tracking analyses would help detect feigned schizophrenic problems. To test this hypothesis, we recorded the eye movements of 83 adult UK volunteers, and tested whether eye movements of healthy volunteers instructed to feign schizophrenia (n = 43) would differ from those of honest controls (n = 40), while engaging in smooth pursuit and pro- and anti-saccade tasks. Additionally, results from our investigation were also compared against previously published data observed in patients with schizophrenia performing similar oculomotor tasks. Data analysis showed that eye movements of experimental participants instructed to feign (a) only partially differed from those of controls and (b) did not closely resemble those from patients with schizophrenia reported in previously published papers. Taken together, these results suggest that examination of eye movements does have the potential to help detecting feigned schizophrenia.

scholarly journals Video-Oculography-Assisted Head Impulse Test and Caloric Testing for Detecting Stroke in Acute Vertigo Patients via Modified HINTS Plus

2021 ◽  
Vol 10 (19) ◽  
pp. 4471
Author(s):  
Timo Siepmann ◽  
Cosima Gruener ◽  
Erik Simon ◽  
Annahita Sedghi ◽  
Hagen H. Kitzler ◽  
...  
Keyword(s):  
Diagnostic Value ◽  
Posterior Circulation ◽  
Head Impulse Test ◽  
Head Impulse ◽  
Caloric Testing ◽  
Patients Âgés ◽  
Video Oculography ◽  
Posterior Circulation Stroke ◽  
Acute Vestibular Syndrome ◽  
Cranial Mri

Background: We assessed whether detection of stroke underlying acute vertigo using HINTS plus (head-impulse test, nystagmus type, test of skew, hearing loss) can be improved by video-oculography for automated head-impulse test (V-HIT) analysis. Methods: We evaluated patients with acute vestibular syndrome (AVS) presenting to the emergency room using HINTS plus and V-HIT-assisted HINTS plus in a randomized sequence followed by cranial MRI and caloric testing. Image-confirmed posterior circulation stroke or vertebrobasilar TIA were the reference standards to calculate diagnostic accuracy. We repeated statistical analysis for a third protocol that was composed post hoc by replacing the head-impulse test with caloric testing in the HINTS plus protocol. Results: We included 30 AVS patients (ages 55.4 ± 17.2 years, 14 females). Of these, 11 (36.7%) had posterior circulation stroke (n = 4) or TIA (n = 7). Acute V-HIT-assisted HINTS plus was feasible and displayed tendentially higher accuracy than conventional HINTS plus (sensitivity: 81.8%, 95% CI 48.2–97.7%; specificity 31.6%, 95% CI 12.6–56.6% vs. sensitivity 72.7%, 95% CI 39.0–94.0%; specificity 36.8%, 95% CI 16.3–61.6%). The new caloric-supported algorithm showed high accuracy (sensitivity 100%, 95% CI 66.4–100%; specificity 66.7%, 95% CI 41–86.7%). Conclusions: Our study provides pilot data on V-HIT-assisted HINTS plus for acute AVS assessment and indicates the diagnostic value of integrated acute caloric testing.

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