scholarly journals Task Dependent Variations of Ocular Lateropulsion in Wallenberg’s Syndrome

1981 ◽  
Vol 8 (1) ◽  
pp. 21-26 ◽  
Author(s):  
T.H. Kirkham ◽  
D. Guitton ◽  
M. Gans
Keyword(s):  
Magnetic Field ◽  
Eye Movements ◽  
Eye Position ◽  
Position Information ◽  
Wallenberg’S Syndrome ◽  
Wallenberg's Syndrome ◽  
Vertical Saccades ◽  
The Right ◽  
Voluntary Saccades ◽  
Multiple Step

SUMMARYThe eye movements of a patient with a left lateral medullary infarct (Wallenberg’s syndrome) were recorded using the scleral search coil in magnetic field technique. When asked to look at spontaneously appearing targets, saccades to the left were generally accurate hut those to the right reached the target by multiple step refixation saccades. Large amplitude rightward saccades were possible between two continuously visible targets or when making voluntary saccades in the dark.Vertical saccades, up or down, between spontaneously appearing targets were always associated with a leftward eye movement (lateropulsion). Voluntary vertical saccades between continuously visible targets showed that upward movements had left lateropulsion but downward movements were normal. Vertical voluntary saccades in the dark were oblique, upward saccades showing left lateropulsion and downward saccades showing rightward deviation. The aberrant horizontal components of vertical saccades had amplitude and velocity characteristics for components of normal oblique saccades. Possibly impaired assessment of vertically with incorrect eye position information produced by the infarct accounts for the lateropulsion of saccades in Wallenberg’s syndrome.

Visually Induced Eye Movements in Wallenberg's Syndrome

1991 ◽  
Vol 111 (sup481) ◽  
pp. 563-566 ◽  
Author(s):  
Ryoji Kanayama ◽  
Tadashi Nakamura ◽  
Makoto Ohki ◽  
Yo Kimura ◽  
Yoshio Koike ◽  
...  
Keyword(s):  
Eye Movements ◽  
Wallenberg’S Syndrome ◽  
Wallenberg's Syndrome

scholarly journals Expansion of Visual Space During Optokinetic Afternystagmus (OKAN)

2008 ◽  
Vol 99 (5) ◽  
pp. 2470-2478 ◽  
Author(s):  
André Kaminiarz ◽  
Bart Krekelberg ◽  
Frank Bremmer
Keyword(s):  
Eye Movements ◽  
Visual Space ◽  
Eye Position ◽  
Control Mechanisms ◽  
Position Information ◽  
Fast Phase ◽  
Optokinetic Afternystagmus ◽  
Perceptual Stability ◽  
Voluntary Eye Movements ◽  
The Brain

The mechanisms underlying visual perceptual stability are usually investigated using voluntary eye movements. In such studies, errors in perceptual stability during saccades and pursuit are commonly interpreted as mismatches between actual eye position and eye-position signals in the brain. The generality of this interpretation could in principle be tested by investigating spatial localization during reflexive eye movements whose kinematics are very similar to those of voluntary eye movements. Accordingly, in this study, we determined mislocalization of flashed visual targets during optokinetic afternystagmus (OKAN). These eye movements are quite unique in that they occur in complete darkness and are generated by subcortical control mechanisms. We found that during horizontal OKAN slow phases, subjects mislocalize targets away from the fovea in the horizontal direction. This corresponds to a perceived expansion of visual space and is unlike mislocalization found for any other voluntary or reflexive eye movement. Around the OKAN fast phases, we found a bias in the direction of the fast phase prior to its onset and opposite to the fast-phase direction thereafter. Such a biphasic modulation has also been reported in the temporal vicinity of saccades and during optokinetic nystagmus (OKN). A direct comparison, however, showed that the modulation during OKAN was much larger and occurred earlier relative to fast-phase onset than during OKN. A simple mismatch between the current eye position and the eye-position signal in the brain is unlikely to explain such disparate results across similar eye movements. Instead, these data support the view that mislocalization arises from errors in eye-centered position information.

Eye position effects in saccadic adaptation

2011 ◽  
Vol 106 (5) ◽  
pp. 2536-2545 ◽  
Author(s):  
Katharina Havermann ◽  
Eckart Zimmermann ◽  
Markus Lappe
Keyword(s):  
Eye Movements ◽  
Visual Space ◽  
Initial Position ◽  
Head Movements ◽  
Eye Position ◽  
Saccade Amplitude ◽  
Position Effects ◽  
Position Information ◽  
Saccadic Adaptation ◽  
Visual Error

Saccades are used by the visual system to explore visual space with the high accuracy of the fovea. The visual error after the saccade is used to adapt the control of subsequent eye movements of the same amplitude and direction in order to keep saccades accurate. Saccadic adaptation is thus specific to saccade amplitude and direction. In the present study we show that saccadic adaptation is also specific to the initial position of the eye in the orbit. This is useful, because saccades are normally accompanied by head movements and the control of combined head and eye movements depends on eye position. Many parts of the saccadic system contain eye position information. Using the intrasaccadic target step paradigm, we adaptively reduced the amplitude of reactive saccades to a suddenly appearing target at a selective position of the eyes in the orbitae and tested the resulting amplitude changes for the same saccade vector at other starting positions. For central adaptation positions the saccade amplitude reduction transferred completely to eccentric starting positions. However, for adaptation at eccentric starting positions, there was a reduced transfer to saccades from central starting positions or from eccentric starting positions in the opposite hemifield. Thus eye position information modifies the transfer of saccadic amplitude changes in the adaptation of reactive saccades. A gain field mechanism may explain the eye position dependence found.

Case report: Wallenberg’s syndrome, a possible cause of symptomatic epicrania fugax

Cephalalgia ◽  
2017 ◽  
Vol 38 (6) ◽  
pp. 1203-1206 ◽  
Author(s):  
Alex Jaimes ◽  
Rafael García-Sáez ◽  
Álvaro Gutiérrez-Viedma ◽  
María-Luz Cuadrado
Keyword(s):  
Case Report ◽  
Primary Headache ◽  
Skull Base Meningioma ◽  
Wallenberg’S Syndrome ◽  
Wallenberg's Syndrome ◽  
Epicrania Fugax ◽  
The Right ◽  
The Temple ◽  
Possible Cause ◽  
Symptomatic Form

Background Epicrania fugax has been described as a primary headache. Nevertheless, a symptomatic form was recently found in a patient with a skull base meningioma abutting the trigeminal nerve. Here we report on a patient with facial pain with the features of epicrania fugax occurring after Wallenberg’s syndrome. Case report A 53-year-old man suffered a right-sided dorsolateral medullary ischaemic stroke. Nine months later, he presented with brief electric shock-like paroxysms of pain stemming from the right eye and radiating to the ipsilateral forehead, the temple or the cheek in a zigzag trajectory. Some episodes were accompanied by ipsilateral conjunctival injection and eyelid oedema. Treatment with eslicarbazepine abolished the pain. Conclusion A pain with the features of epicrania fugax may be associated with medullary lesions. This finding suggests that the central trigeminal pathways and/or the spinal trigeminal nucleus may play an important role in the pathophysiology of this type of pain.

A Method for Rehabilitating Vision after Stroke

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 28-28
Author(s):  
V Virsu ◽  
P Koskela
Keyword(s):  
Eye Movements ◽  
Rectus Muscle ◽  
Eye Position ◽  
Central Vision ◽  
Binocular Fusion ◽  
Primary Position ◽  
Lateral Rectus Muscle ◽  
Correct Function ◽  
One Year ◽  
Voluntary Saccades

We developed a method for rehabilitating eye movements and binocular fusion, and tested the method in one patient. An infarct of the pons caused the paresis of the lateral rectus muscle of the left eye. Beginning from the third week in hospital, the patient was trained in eye movements and binocular fusion. Fusion was made possible by means of prisms that moved the images of targets in central vision to the threshold of fusion in the primary eye position. During practice sessions lasting 0.5 to 2 h daily the patient kept the images fused by making a horizontal head movement when necessary. Several eye-movement sessions were held daily, consisting of voluntary saccades and fixations as far to the left as possible. The strength of the prismatic correction required for fusion decreased, and four months after the onset of stroke the patient could fuse without prisms in the primary position. His binocular vision became practically normal in one year. The plasticity of the visual system can be utilised in rehabilitation by a practice that uses minimal remedial means necessary for correct function at each level of performance.

EYE MOVEMENTS IN PATIENTS WITH WALLENBERG'S SYNDROME

1981 ◽  
Vol 374 (1 Vestibular an) ◽  
pp. 600-613 ◽  
Author(s):  
Robert W. Baloh ◽  
Robert D. Yee ◽  
Vicente Honrubia
Keyword(s):  
Eye Movements ◽  
Wallenberg’S Syndrome ◽  
Wallenberg's Syndrome

Visually induced cross-axis postsaccadic eye drift

1993 ◽  
Vol 69 (4) ◽  
pp. 1031-1043 ◽  
Author(s):  
Z. Kapoula ◽  
D. A. Robinson ◽  
L. M. Optican
Keyword(s):  
Magnetic Field ◽  
Human Subjects ◽  
Vertical Component ◽  
Field Method ◽  
Full Field ◽  
Vertical Saccades ◽  
Before And After ◽  
Cross Axis ◽  
The Right ◽  
Random Dot Pattern

1. It has been previously shown that, if a visual pattern is transiently moved just after every saccade, it is possible to induce horizontal, postsaccadic, ocular drift after horizontal saccades that persists in the dark. In this study we show that horizontal ocular drift can also be created after vertical saccades. Five human subjects viewed binocularly the interior of a full-field hemisphere filled with a random-dot pattern. They were encouraged to make frequent vertical saccades. During training, eye movements were recorded by the electrooculogram. A computer detected the end of every saccade and immediately moved the pattern to the left after up saccades and right after down saccades. The motion was exponential, its amplitude was 25% of the vertical component of the antecedent saccade, its time constant was 50 ms. Before and after 2-3 h of training, movements of both eyes were measured by the eye-coil/magnetic-field method while subjects were instructed to make vertical saccades in the dark, in the presence of the movable adapting pattern, and between stationary targets for calibration. 2. After training (approximately 20,000 saccades) all subjects developed a zero-latency, exponential ocular drift to the left after up saccades and to the right after down saccades. The amplitude of the horizontal drift, expressed as a percentage of the vertical component of the preceding saccade, was 2.7% in the dark. This rose to 10.2% in the presence of the movable adapting stimulus. The latter rise is not due to visual following systems but to a zero-latency increase in initial drift velocity. 3. The horizontal drifts were usually unequal between the two eyes, indicating the presence of disconjugate movements. We measured intrasaccadic disconjugate horizontal movements of all subjects. In agreement with studies by others of saccades in the light, we measured a divergence during up saccades (1.3 degrees) and a convergence for down (0.4 degrees), but in this case for spontaneous saccades in the dark. After training, these values increased for saccades in the dark but decreased in the light in the presence of the adapting stimulus. These changes were largely idiosyncratic and statistically significant in only a few subjects. 4. The cross-axis postsaccadic drifts were separated into their conjugate and disconjugate components. The disconjugate components were small and idiosyncratic, and the means were small for saccades in the dark. The only consistent trend was in the presence of the adapting stimulus where up saccades were often followed by convergence.(ABSTRACT TRUNCATED AT 400 WORDS)

Visually Guided Eye Movements in Patients with Wallenberg's Syndrome

1995 ◽  
Vol 115 (sup519) ◽  
pp. 132-135
Author(s):  
Sadao Ogino ◽  
Isao Kato ◽  
Atsushi Sakuma ◽  
Kaoruko Takahashi ◽  
Isamu Takeyama ◽  
...  
Keyword(s):  
Eye Movements ◽  
Visually Guided ◽  
Wallenberg’S Syndrome ◽  
Wallenberg's Syndrome

scholarly journals Lateral syndrome of the medulla oblongata (Wallenberg's syndrome) as a complication of a vertebral angiography: a case report

1972 ◽  
Vol 30 (1) ◽  
pp. 78-83 ◽  
Author(s):  
Roberto Melaragno
Keyword(s):  
Case Report ◽  
Contrast Medium ◽  
Vertebral Artery ◽  
Medulla Oblongata ◽  
Cerebral Arteries ◽  
Lateral Part ◽  
Direct Puncture ◽  
Wallenberg’S Syndrome ◽  
Wallenberg's Syndrome ◽  
The Right

Case report of a female patient, 58 years old, who, due to a right homonymous hemianopsia, was submitted under general anesthesia successively to angiographies through the right carotid and vertebral arteries. At the first examination no abnormalities were evidenced, but the contrast medium did not reach the posterior cerebral artery; angiography by the right vertebral artery, with extravasation of the contrast medium into the vessel wall, visualized both posterior cerebral arteries. Immediately after the angiographic study, the patient presented the characteristic picture of the Wallenberg's syndrome caused by involvement of the right lateral part of the medulla oblongata. The evolution of the case was good, despite the residual right hemifacial neuralgic pain. An involvement of the vertebral artery, through an intramural injection of Hypaque is assumed to be the most probable pathogenic mechanism. The reported complication is considered as one more warning to prevent angiographies of the vertebral artery through direct puncture of this vessel, due to its recognized anatomical variations.

Functional between-Hand Differences and Outflow Eye Position Information

1984 ◽  
Vol 36 (1) ◽  
pp. 75-88 ◽  
Author(s):  
Hitoshi Honda
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Differential Effect ◽  
Visual Target ◽  
The Other ◽  
Eye Position ◽  
Moving Target ◽  
Position Information ◽  
Pointing Accuracy ◽  
Visible Target

Pointing accuracy with an unseen hand to a just-extinguished visual target was examined in various eye movement conditions. When subjects caught the target by a saccade, they showed about the same degree of accuracy as that shown in pointing to a visible target. On the other hand, when subjects tracked a moving target by a pursuit eye movement, they systematically undershot when subsequently pointing to the target. The differential effect of the two types of eye movements on pointing tasks was examined on both the preferred and non-preferred hands, and it was found that the effect of eye movements was more prominent on the preferred hand than on the non-preferred hand. The results are discussed in relation to outflow eye position information.

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