scholarly journals The Integrated Optokinetic Nystagmus Inter-saccadic Interval Scales Statistical Different In a Group of Vertigo Patients Depended On The Stimulation Velocity, But Not For Healthy Subjects

2021 ◽  
Author(s):  
Torbjørn Aasen
Keyword(s):  
Eye Movements ◽  
Hurst Exponent ◽  
Healthy Subjects ◽  
Optokinetic Nystagmus ◽  
Time Intervals ◽  
Full Field ◽  
Fast Phase ◽  
Left And Right ◽  
Over Time ◽  
Stimulation Of

Abstract Optokinetic nystagmus is rhythmic eye movements, back and forth, with a slow and fast phase, when the eyes are presented for full-field visual stimulus. OKN was recorded in 20 healthy subjects and 20 patients suffering from vertigo, for four conditions: stripes moving 30 o/s left and right and 60 o/s left and right. Calculating the scaling, the spread over time, for the integrated optokinetic nystagmus inter-saccadic interval, the time intervals between the onsets of consecutive fast components, shows lower Hurst exponent for velocity stimulation of 30o/s compared to 60o/s for both patients and health subjects, but only reach statistical differences for the group of patients.

Eye Movements in Cerebellar and Combined Cerebellobrainstem Diseases

1983 ◽  
Vol 92 (2) ◽  
pp. 165-171 ◽  
Author(s):  
Carsten Wennmo ◽  
Bengt Hindfelt ◽  
Ilmari Pyykkö
Keyword(s):  
Quantitative Analysis ◽  
Eye Movements ◽  
Eye Movement ◽  
Smooth Pursuit ◽  
Optokinetic Nystagmus ◽  
Vestibular Nystagmus ◽  
Full Field ◽  
Eye Velocity ◽  
Voluntary Saccades ◽  
Cerebellar Disorders

We report a quantitative analysis of eye movement disturbances in patients with isolated cerebellar disorders and patients with cerebellar disorders and concomitant brainstem involvement. The most characteristic abnormalities in the exclusively cerebellar patients were increased velocities of the slow phases of vestibular nystagmus induced by rotation in the dark and increased peak velocities of the fast phases of optokinetic nystagmus induced by full-field optokinetic stimuli. Dysmetria of saccades was found in three of six cerebellar patients and gaze nystagmus in all six patients. The typical findings in the combined cerebellobrainstem group were reduced peak velocities of voluntary saccades, defective smooth pursuit and reduced peak velocities of the fast component of nystagmus during rotation in both the dark and light. All patients with combined cerebellobrainstem disorder had dysmetric voluntary saccades and gaze nystagmus. The numbers of superimposed saccades during smooth pursuit were uniformly increased. Release of inhibition in cerebellar disorders may explain the hyperresponsiveness and inaccuracy of eye movements found in this study. In addition, when lesions also involve the brainstem, however, integrative centers coding eye velocity are affected, leading to slow and inaccurate eye movements. These features elicited clinically may be useful in the diagnosis of cerebellar and brainstem disorders.

scholarly journals Vestibular implantation and longitudinal electrical stimulation of the semicircular canal afferents in human subjects

2015 ◽  
Vol 113 (10) ◽  
pp. 3866-3892 ◽  
Author(s):  
James O. Phillips ◽  
Leo Ling ◽  
Kaibao Nie ◽  
Elyse Jameyson ◽  
Christopher M. Phillips ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Eye Movements ◽  
Human Subjects ◽  
Vestibular Function ◽  
Slow Phase ◽  
Vestibular Loss ◽  
Stimulation Current ◽  
Eye Velocity ◽  
Over Time ◽  
Stimulation Of

Animal experiments and limited data in humans suggest that electrical stimulation of the vestibular end organs could be used to treat loss of vestibular function. In this paper we demonstrate that canal-specific two-dimensionally (2D) measured eye velocities are elicited from intermittent brief 2 s biphasic pulse electrical stimulation in four human subjects implanted with a vestibular prosthesis. The 2D measured direction of the slow phase eye movements changed with the canal stimulated. Increasing pulse current over a 0–400 μA range typically produced a monotonic increase in slow phase eye velocity. The responses decremented or in some cases fluctuated over time in most implanted canals but could be partially restored by changing the return path of the stimulation current. Implantation of the device in Meniere's patients produced hearing and vestibular loss in the implanted ear. Electrical stimulation was well tolerated, producing no sensation of pain, nausea, or auditory percept with stimulation that elicited robust eye movements. There were changes in slow phase eye velocity with current and over time, and changes in electrically evoked compound action potentials produced by stimulation and recorded with the implanted device. Perceived rotation in subjects was consistent with the slow phase eye movements in direction and scaled with stimulation current in magnitude. These results suggest that electrical stimulation of the vestibular end organ in human subjects provided controlled vestibular inputs over time, but in Meniere's patients this apparently came at the cost of hearing and vestibular function in the implanted ear.

Analysis of vertebrate eye movements following intravitreal drug injections. I. Blockade of retinal ON-cells by 2-amino-4-phosphonobutyrate eliminates optokinetic nystagmus

1988 ◽  
Vol 60 (3) ◽  
pp. 1010-1021 ◽  
Author(s):  
A. G. Knapp ◽  
M. Ariel ◽  
F. R. Robinson
Keyword(s):  
Visual Cortex ◽  
Eye Movements ◽  
Retinal Ganglion Cells ◽  
Optokinetic Nystagmus ◽  
Ganglion Cells ◽  
Directional Asymmetry ◽  
Retinal Ganglion ◽  
Binocular Stimulation ◽  
Vertebrate Eye ◽  
Stimulation Of

1. Horizontal optokinetic nystagmus (OKN) was examined in alert rabbits and cats following intravitreal injection of 2-amino-4-phosphonobutyrate (APB), an agent which selectively blocks the light-responsiveness of retinal ON-cells while having little effect on OFF-cells. The retinal actions of APB were assessed independently by electroretinography. 2. In five rabbits, doses of APB sufficient to eliminate the b-wave of the electroretinogram reduced drastically the ability of the injected eye to drive OKN at all stimulus speeds tested (1-96 degrees/s). Impairment of OKN was apparent within minutes of the injection, remained maximal for several hours, and recovered completely in 1-7 days. OKN in response to stimulation of the uninjected eye alone remained qualitatively and quantitatively normal. 3. Following administration of APB, OKN in response to binocular stimulation displayed a directional asymmetry. Stimuli moving in the preferred (temporal-to-nasal) direction for the uninjected eye became more effective than stimuli moving in the opposite direction, indicating that the injected eye could no longer contribute to binocular OKN. 4. When rabbits viewed stationary stimuli through the APB-treated eye alone, episodes of slow (less than 1 degrees/s) ocular drift were observed, similar to the positional instability seen when rabbits are placed in darkness or when the retinal image is stablized artifically (12). 5. APB had little effect on OKN in normal cats. In two cats that had previously received large lesions of the visual cortex, however, APB eliminated the ability of the injected eye to drive monocular OKN. The extent of the impairment was similar to that seen in rabbits. Because the cortex is thought to contribute more to OKN in cats than in rabbits, this result suggests that the optokinetic pathways disrupted by APB project subcortically. 6. This study demonstrates that the integrity of retinal ON-cells is required to sustain normal OKN. The results are consistent with additional anatomic and physiological evidence suggesting that a particular subclass of retinal ganglion cells, the ON-direction-selective cells, may provide a crucial source of visual input to central optokinetic pathways.

Localisation of Auditory Targets during Optokinetic Nystagmus

Perception ◽  
10.1068/p5849 ◽  
2007 ◽  
Vol 36 (10) ◽  
pp. 1507-1512 ◽  
Author(s):  
Kerstin Königs ◽  
Jonas Knöll ◽  
Frank Bremmer
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Temporal Pattern ◽  
Optokinetic Nystagmus ◽  
Visual Stimuli ◽  
Spatial Location ◽  
Neural Mechanisms ◽  
Auditory Target ◽  
Auditory Stimuli ◽  
Fast Phase

Previous studies have shown that the perceived location of visual stimuli briefly flashed during smooth pursuit, saccades, or optokinetic nystagmus (OKN) is not veridical. We investigated whether these mislocalisations can also be observed for brief auditory stimuli presented during OKN. Experiments were carried out in a lightproof sound-attenuated chamber. Participants performed eye movements elicited by visual stimuli. An auditory target (white noise) was presented for 5 ms. Our data clearly indicate that auditory targets are mislocalised during reflexive eye movements. OKN induces a shift of perceived location in the direction of the slow eye movement and is modulated in the temporal vicinity of the fast phase. The mislocalisation is stronger for look- as compared to stare-nystagmus. The size and temporal pattern of the observed mislocalisation are different from that found for visual targets. This suggests that different neural mechanisms are at play to integrate oculomotor signals and information on the spatial location of visual as well as auditory stimuli.

Characteristics of left and right scanning in schizophrenia patients using exploratory eye movements: Comparison with healthy subjects

2007 ◽  
Vol 61 (5) ◽  
pp. 487-494 ◽  
Author(s):  
SACHIKO NISHIURA ◽  
KIICHIRO MORITA ◽  
KOUJI KURAKAKE ◽  
HIROYASU IGIMI ◽  
HISAO MAEDA
Keyword(s):  
Eye Movements ◽  
Healthy Subjects ◽  
Left And Right

The Aftereffect of Tracking Eye Movements

Perception ◽  
1976 ◽  
Vol 5 (3) ◽  
pp. 309-317 ◽  
Author(s):  
Michael J Morgan ◽  
Roger M Ward ◽  
Edward M Brussell
Keyword(s):  
Eye Movements ◽  
Opposite Direction ◽  
Optokinetic Nystagmus ◽  
Motion Aftereffect ◽  
Moving Target ◽  
Background Stimulation ◽  
Tracking Eye Movements ◽  
Stimulation Of

When observers tracked moving stripes across a background either of stationary stripes, or of stripes moving in the opposite direction, they saw a clear motion aftereffect when the stripes stopped moving. The direction of this aftereffect was opposite to that of the previously tracked stripes, and was thus the same as the direction of the retinal movement of the non-tracked stripes. This aftereffect of tracking was shown not to depend upon slippage of the tracked contours on the retina during tracking, or upon the saccadic phase of optokinetic nystagmus. The effect showed storage over a period of time with the eyes shut. It appears that the effect is due to induced movement, and arises originally from stimulation of the retina by background contours in the tracking phase. This was shown by confining the view of the moving target to one eye, while permitting both eyes to be exposed to background stimulation during tracking. After such stimulation the magnitude of the aftereffect was equal in the two eyes.

scholarly journals Occipital Petalia and Albinism: A Study of Interhemispheric VEP Asymmetries in Albinism with No Nystagmus

2019 ◽  
Vol 8 (6) ◽  
pp. 802 ◽  
Author(s):  
Alkiviades Liasis ◽  
Sian E. Handley ◽  
Ken K. Nischal
Keyword(s):  
Right Hemisphere ◽  
Normal Subjects ◽  
Visual Pathway ◽  
Field Pattern ◽  
Pattern Reversal ◽  
Full Field ◽  
Pathway Function ◽  
Left And Right ◽  
The Right ◽  
Stimulation Of

The purpose of this study was to assess chiasmal misrouting in a cohort of children with albinism with no nystagmus using hemifield visual evoked potentials (VEP) measures. Methods: Monocular VEPs were recorded and analyzed from three electrodes (O1, Oz, and O2 referred to Fz) from 16 children with albinism without nystagmus. Pattern reversal (full field and hemifield stimulation), full field pattern appearance and flash stimuli were used to evoke VEPs for each eye. Results: The amplitude of the pattern reversal VEPs to stimulation of the hemifield corresponding to the crossing pathways were as expected significantly larger than those to the non-crossing in each eye ((right eye p = 0.000004), (left eye p = 0.001)). Pattern reversal VEPs recorded from the left hemisphere were also larger than those from the right and most evident when comparing the crossing pathways of each eye (p = 0.004). Conclusions: This study has demonstrated electrophysiological differences in visual pathway function of the left and right hemisphere in subjects with albinism like that previously described in controls. Nasal field stimulation activated crossing and non-crossing pathways in patients with albinism and as a result, nasal hemifield VEPs in albinism are less lateralized compared to what is found in normal subjects.

scholarly journals Effects of emotionally charged sounds in schizophrenia patients using exploratory eye movements: Comparison with healthy subjects

2010 ◽  
Vol 64 (1) ◽  
pp. 10-18 ◽  
Author(s):  
Youhei Ishii ◽  
Kiichiro Morita ◽  
Yoshihisa Shouji ◽  
Youko Nakashima ◽  
Naohisa Uchimura
Keyword(s):  
Eye Movements ◽  
Healthy Subjects

A Longitudinal Study of Anteroposterior Growth Changes in the Palatine Rugae

1987 ◽  
Vol 66 (9) ◽  
pp. 1512-1515 ◽  
Author(s):  
J.D. Simmons ◽  
R.N. Moore ◽  
L.C. Erickson
Keyword(s):  
Repeated Measures ◽  
Reference Points ◽  
Differential Growth ◽  
Time Intervals ◽  
Child Research ◽  
Left And Right ◽  
Growth Changes ◽  
Observation Times ◽  
Dental Cast ◽  
Tooth Migration

Palatine rugae have been used as internal dental cast reference points for quantification of tooth migration. Some, but not all, investigators have reported the medial rugal region to be stable or to show predictable change. The purpose of this study was to use the longitudinal data base of the Child Research Council of Denver to examine the anteroposterior stability of the medial rugal region. Dental casts of 20 females and 21 males with untreated normal Angle Class I occlusions were selected. Time intervals measured were: T1 — primary teeth erupted, T2 — earliest cast with permanent first molars erupted, T3 - earliest cast with canines and pre-molars erupted, and T4 — ages 16 to 22. Distinctive left and right anterior and posterior rugae which appeared on all four casts were identified, the medial ends marked, and the anteroposterior distances measured. The data were evaluated with the paired t test, repeated-measures AN-OVA, and Tukey's multiple comparison procedure. From T1 - T4, the medial rugal region increased 1.4±0.6 mm in females and 2.3±0.8 mm in males. Only two cases showed a trend toward stability. There were no significant differences by side. Significant increases in size occurred between T2 and T3 for females and males and between T3 and T4 for males. Analysis of these data indicates that the medial rugal region increases significantly in anteroposterior length, but not uniformly between the sexes across observation times. Such changes are characteristic of general craniofacial growth and suggest that the rugal region is responding to the differential growth of the underlying bone. Therefore, medial rugal landmarks appear not to be stable reference points for tooth migration research.

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