scholarly journals Role of electronystagmography as a definitive tool in evaluation of vertigo: a clinical study

2021 ◽  
Vol 7 (6) ◽  
pp. 1026
Author(s):  
C. B. Nandyal ◽  
Ramchandra .
Keyword(s):  
Clinical Study ◽  
Screening Tool ◽  
Optimal Conditions ◽  
Special Significance ◽  
First Line ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex ◽  
Benign Positional Paroxysmal Vertigo ◽  
The Brain

<p class="abstract"><strong>Background:</strong> Vertigo is one of the most distressing symptoms. It is difficult to identify, practically impossible to measure and not easy to treat. Electronystagmography (ENG) objectively records eye movements and thus tests the functional integrity of vestibulo-ocular reflex and its connections from inner ear to the brain. Hence, this present study was taken to evaluate the role of ENG in the diagnosis of vertigo, to know the peripheral, central and other causes of vertigo and to know the side of lesion. The aim of this study was to evaluate the role of ENG in the diagnosis of vertigo, to know the peripheral, central and other causes of vertigo and to know the side of lesion.</p><p class="abstract"><strong>Methods:</strong> This study included 60 patients who presented with primary complaints of vertigo or dizziness. Patients were subjected to ENG under optimal conditions and the results were obtained in the form of a graphical recordings after analysis of the ENG data.</p><p class="abstract"><strong>Results:</strong> Of the 60 patients subjected to ENG, a peripheral cause was seen in 33 patients. 21 patients were diagnosed with benign positional paroxysmal vertigo (BPPV), whereas 06 patients showed a central lesion of the vestibular system.</p><p class="abstract"><strong>Conclusions:</strong> ENG acts as a useful screening tool to differentiate between peripheral cause of vertigo and central cause of vertigo. It has special significance in localizing the side of the lesion. Hence, ENG has proven to be a useful first line investigation in the diagnosis of vertigo.</p>

scholarly journals Eye and head movements and vestibulo-ocular reflex in the context of indirect, referent control of motor actions

2020 ◽  
Vol 124 (1) ◽  
pp. 115-133 ◽  
Author(s):  
Anatol G. Feldman ◽  
Lei Zhang
Keyword(s):  
Empirical Studies ◽  
Head Rotation ◽  
Physical Principle ◽  
Task Demands ◽  
Head Movements ◽  
Ocular Reflex ◽  
Motor Outcome ◽  
Vestibulo Ocular Reflex ◽  
Motor Actions ◽  
The Brain

Conventional explanations of the vestibulo-ocular reflex (VOR) and eye and head movements are revisited by considering two alternative frameworks addressing the question of how the brain controls motor actions. Traditionally, biomechanical and/or computational frameworks reflect the views of several prominent scholars of the past, including Helmholtz and von Holst, who assumed that the brain directly specifies the desired motor outcome and uses efference copy to influence perception. However, empirical studies resulting in the theory of referent control of action and perception (an extension of the equilibrium-point hypothesis) revealed that direct specification of motor outcome is inconsistent with nonlinear properties of motoneurons and with the physical principle that the brain can control motor actions only indirectly, by changing or maintaining the values of neurophysiological parameters that influence, but can remain independent of, biomechanical variables. Some parameters are used to shift the origin (referent) points of spatial frames of reference (FRs) or system of coordinates in which motor actions emerge without being predetermined. Parameters are adjusted until the emergent motor actions meet the task demands. Several physiological parameters and spatial FRs have been identified, supporting the notion of indirect, referent control of movements. Instead of integration of velocity-dependent signals, position-dimensional referent signals underlying head motion can likely be transmitted to motoneurons of extraocular muscles. This would produce compensatory eye movement preventing shifts in gaze during head rotation, even after bilateral destruction of the labyrinths. The referent control framework symbolizes a shift in the paradigm for the understanding of VOR and eye and head movement production.

scholarly journals Role of Cerebellum in Motion Perception and Vestibulo-ocular Reflex—Similarities and Disparities

2012 ◽  
Vol 12 (1) ◽  
pp. 97-107 ◽  
Author(s):  
Aasef G. Shaikh ◽  
Antonella Palla ◽  
Sarah Marti ◽  
Itsaso Olasagasti ◽  
Lance M. Optican ◽  
...  
Keyword(s):  
Motion Perception ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex

Self-motion perception and vestibulo-ocular reflex during whole body yaw rotation in standing subjects: The role of head position and neck proprioception

2011 ◽  
Vol 30 (2) ◽  
pp. 314-332 ◽  
Author(s):  
Roberto Panichi ◽  
Fabio Massimo Botti ◽  
Aldo Ferraresi ◽  
Mario Faralli ◽  
Artemis Kyriakareli ◽  
...  
Keyword(s):  
Motion Perception ◽  
Head Position ◽  
Whole Body ◽  
Ocular Reflex ◽  
Neck Proprioception ◽  
Vestibulo Ocular Reflex ◽  
Self Motion

scholarly journals Gating of neural error signals during motor learning

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Rhea R Kimpo ◽  
Jacob M Rinaldi ◽  
Christina K Kim ◽  
Hannah L Payne ◽  
Jennifer L Raymond
Keyword(s):  
Motor Learning ◽  
Climbing Fiber ◽  
Climbing Fibers ◽  
Motor Memory ◽  
Ocular Reflex ◽  
Learning Tasks ◽  
Performance Errors ◽  
Vestibulo Ocular Reflex

Cerebellar climbing fiber activity encodes performance errors during many motor learning tasks, but the role of these error signals in learning has been controversial. We compared two motor learning paradigms that elicited equally robust putative error signals in the same climbing fibers: learned increases and decreases in the gain of the vestibulo-ocular reflex (VOR). During VOR-increase training, climbing fiber activity on one trial predicted changes in cerebellar output on the next trial, and optogenetic activation of climbing fibers to mimic their encoding of performance errors was sufficient to implant a motor memory. In contrast, during VOR-decrease training, there was no trial-by-trial correlation between climbing fiber activity and changes in cerebellar output, and climbing fiber activation did not induce VOR-decrease learning. Our data suggest that the ability of climbing fibers to induce plasticity can be dynamically gated in vivo, even under conditions where climbing fibers are robustly activated by performance errors.

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