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An Approach to a Patient with Gaze Disorder
Published in Vivek Lal, A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
Ask the patient to gaze at a stationary object. In a normal person, the eyes should remain still. Examiner observes for eye movements that take the eyes off the target, for example, a fast jerky eye movement (saccadic intrusions) or slow drifts followed by fast corrective saccades (nystagmus). One may have to observe for at least 10–15 minutes to detect their presence. Minimal amplitude saccadic intrusions, easily missed by the untrained observer, can be picked up by watching the retinal vessels through an ophthalmoscope. In dedicated centers, oculography and video oculography can be used to detect these defects in gaze fixation with higher sensitivity [7].
Observational analysis of nystagmic oscillations by two-dimensional video-oculography
Published in Jan-Tjeerd de Faber, 28th European Strabismological Association Meeting, 2020
R. Frosini, L. Frosini, P. Linari, S. Frosini, S. Brogelli, G. Alfieri
Objective: To study nystagmic oscillations of ophthalmological interest by means of 2DVOG ™(two-dimensional video-oculography),a recently introduced technology which has shown to be useful in monitoring patients affected by oto-vestibular illnesses.
Evaluation of Balance
Published in John C Watkinson, Raymond W Clarke, Christopher P Aldren, Doris-Eva Bamiou, Raymond W Clarke, Richard M Irving, Haytham Kubba, Shakeel R Saeed, Paediatrics, The Ear, Skull Base, 2018
There are many techniques available and they all offer advantages and disadvantages. The two techniques usually available in ENT or audiology departments are electro-oculography (EOG) and video-oculography (VOG). These two techniques are relatively easy to set up, inexpensive, non-invasive and have a range of signal linearity of approximately ±20–30 degrees, capable of coping with the large eye movements encountered during vestibular tests in the dark. The main disadvantages are poor spatial (EOG) and temporal (VOG) resolution, but in the clinical vestibular setting these two techniques are the ones to be recommended (note that EOG and electronystagmography (ENG), are synonymous). An increasingly popular use of VOG is as part of the video head-impulse test (VHIT).
Static cervico-ocular reflex in healthy humans
Published in Acta Oto-Laryngologica, 2023
Tomoki Ooka, Keiji Honda, Takeshi Tsutsumi
This study aimed to verify the existence of static COR in healthy individuals. We observed torsional eye movement in a head-upright-with-body-tilt (HUBT) position using video oculography. We considered this eye movement to be a static COR in the roll plane (static tilting COR). Video oculography is a direct and objective method that can accurately measure torsional eye movement and has the potential to identify static COR in normal individuals. Experiment 1 aimed to detect the static COR observed as eye torsion during the HUBT position and assess the correlation between the amplitude of COR and degree of neck flexion. Experiment 2 aimed to minimise the influence of dynamic VOR more strictly than Experiment 1 and assess the influence of static COR on OCR by comparing OCR during head tilt with OCR during whole-body tilt.
A case of apogeotropic horizontal canal benign paroxysmal positional vertigo that transformed to the geotropic variant during treatment with Appiani maneuver, followed by successful treatment with Gufoni maneuver
Published in Physiotherapy Theory and Practice, 2022
In developing countries, the video recording of nystagmus during positional tests in patients suspected to have benign paroxysmal positional vertigo is a low-cost, yet useful alternative to the high-cost video-oculography. It is not only reassuring for the treating doctor to observe positional nystagmus disappear after a repositioning maneuver but it also sometimes aids in recognizing the pattern of nystagmus, especially if it is very short-lasting. In patients suspected to have BPPV who visit our center for a consultation, the positional tests are done by recording the eye movement using a 5-inch Google pixel camera.1 Subsequently, an appropriate session of repositioning maneuver is executed and recorded in some patients for teaching purposes. The verifying positional test is done not earlier than 1 h after the session of a repositioning maneuver, and this is also video recorded to document the disappearance of positional nystagmus. In the case presented here, the transformation from the apogeotropic to geotropic positional nystagmus was not merely observed, but we were able to record as the case evolved from examination to intervention with the therapeutic maneuvers.
Neuro-Ophthalmic Literature Review
Published in Neuro-Ophthalmology, 2021
David A. Bellows, Noel C.Y. Chan, John J. Chen, Hui-Chen Cheng, Jenny A. Nij Bijvank, Michael S. Vaphiades, Konrad P. Weber, Sui H. Wong, Xiaojun Zhang
Textbook knowledge suggests that failure of spontaneous nystagmus suppression by looking at a target should be interpreted as a central clinical sign. To validate this assumption, the authors enrolled 148 patients with acute vestibular syndrome at the emergency room. 56 of them were diagnosed with vestibular neuritis, 28 with stroke. They measured their spontaneous nystagmus with video oculography and calculated an ocular fixation index (OFI). They found that OFI scores had no predictive value for detecting strokes. Accordingly, they found that nystagmus suppression of less than 2°/s as measured with video oculography had a modest sensitivity (62.2%) but high specificity (84.8%) to detect a stroke. Therefore, they inferred that a decreased nystagmus suppression is specific to rule in a stroke, but the presence of fixation suppression does not rule out an intracerebral lesion. But to take advantage of this conclusion, nystagmus measures with video oculography are needed. However, from a practical point of view, it is probably difficult to measure such subtle differences in nystagmus suppression reliably in the busy environment of an emergency room.