1
|
Lee MY, Son HR, Rah YC, Jung JY, Suh MW. Recovery Phase Spontaneous Nystagmus, Its Existence and Clinical Implication. J Audiol Otol 2018; 23:33-38. [PMID: 30518197 PMCID: PMC6348311 DOI: 10.7874/jao.2018.00206] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 07/31/2018] [Indexed: 12/04/2022] Open
Abstract
Background and Objectives Determination of the lesion side based on the direction of the nystagmus could result in confusions to the clinicians due to mismatch between the vestibular function tests and also between vestibular and audiologic features. To minimize these mistakes, we elucidated the clinical manifestation and vestibular function test results in cases with recovery spontaneous nystagmus (rSN). Subjects and Methods Patients who visited ENT clinic of tertiary referral hospital for acute onset continuous vertigo from January 2008 to December 2011 were enrolled. In these patients, we assessed onset time of vertigo, time point of paralytic spontaneous nystagmus (SN) and time point of rSN. At each time point of SN, vestibular function tests and hearing function tests were performed. Results We confirmed the rSN among patients with unilateral vestibulopathy and demonstrated that high gain of the rotatory chair test (slow harmonic acceleration) and/or mismatch of the SN direction and contralateral caloric weakness could indicate the recovery state of patients and nystagmus observed in this stage is recovery phase nystagmus. Conclusions In acute vestibulopathy patients, recovery phase nystagmus was observed and on this stage of disease vestibular function tests shows several features that could predict recovery state.
Collapse
Affiliation(s)
- Min Young Lee
- Department of Otorhinolaryngology-Head & Neck Surgery, Dankook University Hospital, Cheonan, Korea
| | - Hye Ran Son
- Department of Otorhinolaryngology-Head & Neck Surgery, Dankook University Hospital, Cheonan, Korea
| | - Yoon Chan Rah
- Department of Otorhinolaryngology-Head & Neck Surgery, Korea University Ansan Hospital, Ansan, Korea
| | - Jae Yun Jung
- Department of Otorhinolaryngology-Head & Neck Surgery, Dankook University Hospital, Cheonan, Korea
| | - Myung-Whan Suh
- Department of Otorhinolaryngology-Head & Neck Surgery, Seoul National University Hospital, Seoul, Korea
| |
Collapse
|
2
|
Corneil BD, Camp AJ. Animal Models of Vestibular Evoked Myogenic Potentials: The Past, Present, and Future. Front Neurol 2018; 9:489. [PMID: 29988517 PMCID: PMC6026641 DOI: 10.3389/fneur.2018.00489] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 06/05/2018] [Indexed: 11/13/2022] Open
Abstract
Vestibular-evoked myogenic potentials (VEMPs) provide a simple and cost-effective means to assess the patency of vestibular reflexes. VEMP testing constitutes a core screening method in a clinical battery that probes vestibular function. The confidence one has in interpreting the results arising from VEMP testing is linked to a fundamental understanding of the underlying functional anatomy and physiology. In this review, we will summarize the key role that studies across a range of animal models have fulfilled in contributing to this understanding, covering key findings regarding the mechanisms of excitation in the sensory periphery, the processing of sensory information in central networks, and the distribution of reflexive output to the motor periphery. Although VEMPs are often touted for their simplicity, work in animals models have emphasized how vestibular reflexes operate within a broader behavioral and functional context, and as such vestibular reflexes are influenced by multisensory integration, governed by task demands, and follow principles of muscle recruitment. We will conclude with considerations of future questions, and the ways in which studies in current and emerging animal models can contribute to further use and refinement of this test for both basic and clinical research purposes.
Collapse
Affiliation(s)
- Brian D. Corneil
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON, Canada
- Department of Psychology, University of Western Ontario, London, ON, Canada
- Robarts Research Institute, University of Western Ontario, London, ON, Canada
| | - Aaron J. Camp
- Discipline of Biomedical Science, Sydney Medical School, University of Sydney, Sydney, NSW, Australia
| |
Collapse
|
3
|
Izawa Y, Suzuki H. Motor action of the frontal eye field on the eyes and neck in the monkey. J Neurophysiol 2018. [PMID: 29513149 DOI: 10.1152/jn.00577.2017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Focal stimulation in the frontal eye field (FEF) evoked eye movements that were often accompanied by neck movements. Experiments were performed with concurrent recording of both movements in trained monkeys. We recorded neck forces under a head-restrained condition with a force-measuring system. With the system, we measured forces along the x-, y-, and z-axes and torque about the z-axis. Torque about the z-axis that represented yaw rotation of the head was significantly affected by stimulation. We found that stimulation generated two types of motor actions of the eyes and neck. In the first type, contraversive neck forces were evoked by stimulation of the medial part of the FEF, where contraversive saccadic eye movements with large amplitudes were evoked. When the stimulus intensity was increased, saccades were evoked in an all-or-none manner, whereas the amplitude of neck forces increased gradually. In the second type, contraversive neck forces were evoked by stimulation of the medial and caudal part of the FEF, where ipsiversive slow eye movements were evoked. The depth profiles of amplitudes of neck forces were almost parallel to those of eye movements in individual stimulation tracks. The present results suggest that the FEF is involved in the control of motor actions of the neck as well as the eyes. The FEF area associated with contraversive saccades and contraversive neck movements may contribute to a gaze shift process, whereas that associated with ipsiversive slow eye movements and contraversive neck movements may contribute to a visual stabilization process. NEW & NOTEWORTHY Focal stimulation in the frontal eye field (FEF) evoked eye and neck movements. We recorded neck forces under a head-restrained condition with a force-measuring system. Taking advantage of this approach, we could analyze slow eye movements that were dissociated from the vestibuloocular reflex. We found ipsiversive slow eye movements in combination with contraversive neck forces, suggesting that the FEF may be a source of a corollary discharge signal for compensatory eye movements during voluntary neck movements.
Collapse
Affiliation(s)
- Yoshiko Izawa
- Department of Systems Neurophysiology, Graduate School of Medicine, Tokyo Medical and Dental University, Yushima, Bunkyo-ku, Tokyo , Japan
| | - Hisao Suzuki
- Department of Systems Neurophysiology, Graduate School of Medicine, Tokyo Medical and Dental University, Yushima, Bunkyo-ku, Tokyo , Japan
| |
Collapse
|
4
|
MacNeilage PR, Glasauer S. Quantification of Head Movement Predictability and Implications for Suppression of Vestibular Input during Locomotion. Front Comput Neurosci 2017. [PMID: 28638335 PMCID: PMC5461342 DOI: 10.3389/fncom.2017.00047] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Achieved motor movement can be estimated using both sensory and motor signals. The value of motor signals for estimating movement should depend critically on the stereotypy or predictability of the resulting actions. As predictability increases, motor signals become more reliable indicators of achieved movement, so weight attributed to sensory signals should decrease accordingly. Here we describe a method to quantify this predictability for head movement during human locomotion by measuring head motion with an inertial measurement unit (IMU), and calculating the variance explained by the mean movement over one stride, i.e., a metric similar to the coefficient of determination. Predictability exhibits differences across activities, being most predictable during running, and changes over the course of a stride, being least predictable around the time of heel-strike and toe-off. In addition to quantifying predictability, we relate this metric to sensory-motor weighting via a statistically optimal model based on two key assumptions: (1) average head movement provides a conservative estimate of the efference copy prediction, and (2) noise on sensory signals scales with signal magnitude. The model suggests that differences in predictability should lead to changes in the weight attributed to vestibular sensory signals for estimating head movement. In agreement with the model, prior research reports that vestibular perturbations have greatest impact at the time points and during activities where high vestibular weight is predicted. Thus, we propose a unified explanation for time-and activity-dependent modulation of vestibular effects that was lacking previously. Furthermore, the proposed predictability metric constitutes a convenient general method for quantifying any kind of kinematic variability. The probabilistic model is also general; it applies to any situation in which achieved movement is estimated from both motor signals and zero-mean sensory signals with signal-dependent noise.
Collapse
Affiliation(s)
- Paul R MacNeilage
- German Center for Vertigo and Balance Disorders, University Hospital of MunichMunich, Germany
| | - Stefan Glasauer
- German Center for Vertigo and Balance Disorders, University Hospital of MunichMunich, Germany.,Center for Sensorimotor Research and Department of Neurology, Ludwig-Maximilian-University MunichMunich, Germany
| |
Collapse
|
5
|
Kolev OI, Reschke MF. Acquisition of Predictable Vertical Visual Targets: Eye-Head Coordination and the Triggering Effect. J Mot Behav 2016; 48:552-561. [PMID: 27362612 DOI: 10.1080/00222895.2016.1161589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The study was designed to investigate target acquisition in the vertical plane with emphasis on establishing strategy differences associated with acquisition triggering methods. Eight subjects were tested. Measurements consisted of target acquisition time, eye-head latency differences, velocity of gaze, eyes and head, and head amplitude. Using 3-way repeated measures analyses of variance the results show that the strategy for acquisition of predictable visual targets in vertical plane with the head unrestrained significantly depended on (a) the direction of the gaze motion with respect to the gravity vector (i.e., there is significant up-down asymmetry), (b) the angular distance of the target, and (c) the method of triggering the command to acquire the target-external versus internal. The data also show that when vertical acquisition is compared with triggering methods in the horizontal plane there is a difference in overall strategy for the acquisition of targets with the same spatial distances from straight ahead gaze when both the eyes and head are used. Among the factors contributing to the difference in strategy for vertical target acquisition are the gravitational vector, the relationship of target displacement and vestibular activitation, biomechanical and neural control asymmetries, and the difference in the vertical field of view.
Collapse
Affiliation(s)
- Ognyan I Kolev
- a Neurosciences Laboratories, NASA Johnson Space Center , Houston , Texas , USA.,b Medical University-Sofia, University Hospital of Neurology and Psychiatry "St. Naum" , Sofia , Bulgaria
| | - Millard F Reschke
- a Neurosciences Laboratories, NASA Johnson Space Center , Houston , Texas , USA
| |
Collapse
|
6
|
Hänzi S, Banchi R, Straka H, Chagnaud BP. Locomotor corollary activation of trigeminal motoneurons: coupling of discrete motor behaviors. ACTA ACUST UNITED AC 2016; 218:1748-58. [PMID: 26041033 DOI: 10.1242/jeb.120824] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
During motor behavior, corollary discharges of the underlying motor commands inform sensory-motor systems about impending or ongoing movements. These signals generally limit the impact of self-generated sensory stimuli but also induce motor reactions that stabilize sensory perception. Here, we demonstrate in isolated preparations of Xenopus laevis tadpoles that locomotor corollary discharge provokes a retraction of the mechanoreceptive tentacles during fictive swimming. In the absence of sensory feedback, these signals activate a cluster of trigeminal motoneurons that cause a contraction of the tentacle muscle. This corollary discharge encodes duration and strength of locomotor activity, thereby ensuring a reliable coupling between locomotion and tentacle motion. The strict phase coupling between the trigeminal and spinal motor activity, present in many cases, suggests that the respective corollary discharge is causally related to the ongoing locomotor output and derives at least in part from the spinal central pattern generator; however, additional contributions from midbrain and/or hindbrain locomotor centers are likely. The swimming-related retraction might protect the touch-receptive Merkel cells on the tentacle from sensory over-stimulation and damage and/or reduce the hydrodynamic drag. The intrinsic nature of the coupling of tentacle retraction to locomotion is an excellent example of a context-dependent, direct link between otherwise discrete motor behaviors.
Collapse
Affiliation(s)
- Sara Hänzi
- Department Biology II, Ludwig-Maximilians-University Munich, 82152 Planegg, Germany Graduate School of Systemic Neurosciences, Ludwig-Maximilians-University Munich, 82152 Planegg, Germany
| | - Roberto Banchi
- Department Biology II, Ludwig-Maximilians-University Munich, 82152 Planegg, Germany Graduate School of Systemic Neurosciences, Ludwig-Maximilians-University Munich, 82152 Planegg, Germany
| | - Hans Straka
- Department Biology II, Ludwig-Maximilians-University Munich, 82152 Planegg, Germany
| | - Boris P Chagnaud
- Department Biology II, Ludwig-Maximilians-University Munich, 82152 Planegg, Germany
| |
Collapse
|
7
|
Dietrich H, Straka H. Prolonged vestibular stimulation induces homeostatic plasticity of the vestibulo-ocular reflex in larval Xenopus laevis. Eur J Neurosci 2016; 44:1787-96. [PMID: 27152983 DOI: 10.1111/ejn.13269] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 04/21/2016] [Accepted: 04/22/2016] [Indexed: 12/18/2022]
Abstract
Vestibulo-ocular reflexes (VOR) stabilise retinal images during head/body motion in vertebrates by generating spatio-temporally precise extraocular motor commands for corrective eye movements. While VOR performance is generally robust with a relatively stable gain, cerebellar circuits are capable of adapting the underlying sensory-motor transformation. Here, we studied cerebellum-dependent VOR plasticity by recording head motion-induced lateral rectus and superior oblique extraocular motor discharge in semi-intact preparations of Xenopus laevis tadpoles. In the absence of visual feedback, prolonged sinusoidal rotation caused either an increase or decrease of the VOR gain depending on the motion stimulus amplitude. The observed changes in extraocular motor discharge gradually saturated after 20 min of constant rotation and returned to baseline in the absence of motion stimulation. Furthermore, plastic changes in lateral rectus and superior oblique motor commands were plane-specific for horizontal and vertical rotations, respectively, suggesting that alterations are restricted to principal VOR connections. Comparison of multi- and single-unit activity indicated that plasticity occurs in all recorded units of a given extraocular motor nucleus. Ablation of the cerebellum abolished motoneuronal gain changes and prevented the induction of plasticity, thus demonstrating that both acquisition and retention of this type of plasticity require an intact cerebellar circuitry. In conclusion, the plane-specific and stimulus intensity-dependent modification of the VOR gain through the feed-forward cerebellar circuitry represents a homeostatic plasticity that likely maintains an optimal working range for the underlying sensory-motor transformation.
Collapse
Affiliation(s)
- Haike Dietrich
- Department Biology II, Ludwig-Maximilians-University Munich, Großhaderner Str. 2, Planegg, 82152, Germany.,Graduate School of Systemic Neurosciences, Ludwig-Maximilians-University Munich, Planegg, Germany
| | - Hans Straka
- Department Biology II, Ludwig-Maximilians-University Munich, Großhaderner Str. 2, Planegg, 82152, Germany
| |
Collapse
|
8
|
Poletti M, Aytekin M, Rucci M. Head-Eye Coordination at a Microscopic Scale. Curr Biol 2015; 25:3253-9. [PMID: 26687623 DOI: 10.1016/j.cub.2015.11.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 10/28/2015] [Accepted: 11/03/2015] [Indexed: 10/22/2022]
Abstract
Humans explore static visual scenes by alternating rapid eye movements (saccades) with periods of slow and incessant eye drifts [1-3]. These drifts are commonly believed to be the consequence of physiological limits in maintaining steady gaze, resulting in Brownian-like trajectories [4-7], which are almost independent in the two eyes [8-10]. However, because of the technical difficulty of recording minute eye movements, most knowledge on ocular drift comes from artificial laboratory conditions, in which the head of the observer is strictly immobilized. Little is known about eye drift during natural head-free fixation, when microscopic head movements are also continually present [11-13]. We have recently observed that the power spectrum of the visual input to the retina during ocular drift is largely unaffected by fixational head movements [14]. Here we elucidate the mechanism responsible for this invariance. We show that, contrary to common assumption, ocular drift does not move the eyes randomly, but compensates for microscopic head movements, thereby yielding highly correlated movements in the two eyes. This compensatory behavior is extremely fast, persists with one eye patched, and results in image motion trajectories that are only partially correlated on the two retinas. These findings challenge established views of how humans acquire visual information. They show that ocular drift is precisely controlled, as long speculated [15], and imply the existence of neural mechanisms that integrate minute multimodal signals.
Collapse
Affiliation(s)
- Martina Poletti
- Department of Psychological and Brain Sciences, Boston University, Boston, MA 02215, USA
| | - Murat Aytekin
- Department of Psychological and Brain Sciences, Boston University, Boston, MA 02215, USA
| | - Michele Rucci
- Department of Psychological and Brain Sciences, Boston University, Boston, MA 02215, USA; Graduate Program in Neuroscience, Boston University, Boston, MA 02215, USA.
| |
Collapse
|
9
|
Göttlich M, Jandl NM, Wojak JF, Sprenger A, von der Gablentz J, Münte TF, Krämer UM, Helmchen C. Altered resting-state functional connectivity in patients with chronic bilateral vestibular failure. NEUROIMAGE-CLINICAL 2014; 4:488-99. [PMID: 24818075 PMCID: PMC3984447 DOI: 10.1016/j.nicl.2014.03.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 02/26/2014] [Accepted: 03/09/2014] [Indexed: 12/30/2022]
Abstract
Patients with bilateral vestibular failure (BVF) suffer from gait unsteadiness, oscillopsia and impaired spatial orientation. Brain imaging studies applying caloric irrigation to patients with BVF have shown altered neural activity of cortical visual-vestibular interaction: decreased bilateral neural activity in the posterior insula and parietal operculum and decreased deactivations in the visual cortex. It is unknown how this affects functional connectivity in the resting brain and how changes in connectivity are related to vestibular impairment. We applied a novel data driven approach based on graph theory to investigate altered whole-brain resting-state functional connectivity in BVF patients (n= 22) compared to age- and gender-matched healthy controls (n= 25) using resting-state fMRI. Changes in functional connectivity were related to subjective (vestibular scores) and objective functional parameters of vestibular impairment, specifically, the adaptive changes during active (self-guided) and passive (investigator driven) head impulse test (HIT) which reflects the integrity of the vestibulo-ocular reflex (VOR). BVF patients showed lower bilateral connectivity in the posterior insula and parietal operculum but higher connectivity in the posterior cerebellum compared to controls. Seed-based analysis revealed stronger connectivity from the right posterior insula to the precuneus, anterior insula, anterior cingulate cortex and the middle frontal gyrus. Excitingly, functional connectivity in the supramarginal gyrus (SMG) of the inferior parietal lobe and posterior cerebellum correlated with the increase of VOR gain during active as compared to passive HIT, i.e., the larger the adaptive VOR changes the larger was the increase in regional functional connectivity. Using whole brain resting-state connectivity analysis in BVF patients we show that enduring bilateral deficient or missing vestibular input leads to changes in resting-state connectivity of the brain. These changes in the resting brain are robust and task-independent as they were found in the absence of sensory stimulation and without a region-related a priori hypothesis. Therefore they may indicate a fundamental disease-related change in the resting brain. They may account for the patients' persistent deficits in visuo-spatial attention, spatial orientation and unsteadiness. The relation of increasing connectivity in the inferior parietal lobe, specifically SMG, to improvement of VOR during active head movements reflects cortical plasticity in BVF and may play a clinical role in vestibular rehabilitation.
Collapse
Affiliation(s)
- Martin Göttlich
- Department of Neurology, University of Lübeck, Ratzeburger Allee 160, Lübeck 23538, Germany
| | - Nico M Jandl
- Department of Neurology, University of Lübeck, Ratzeburger Allee 160, Lübeck 23538, Germany
| | - Jann F Wojak
- Department of Neurology, University of Lübeck, Ratzeburger Allee 160, Lübeck 23538, Germany
| | - Andreas Sprenger
- Department of Neurology, University of Lübeck, Ratzeburger Allee 160, Lübeck 23538, Germany
| | | | - Thomas F Münte
- Department of Neurology, University of Lübeck, Ratzeburger Allee 160, Lübeck 23538, Germany
| | - Ulrike M Krämer
- Department of Neurology, University of Lübeck, Ratzeburger Allee 160, Lübeck 23538, Germany
| | - Christoph Helmchen
- Department of Neurology, University of Lübeck, Ratzeburger Allee 160, Lübeck 23538, Germany
| |
Collapse
|
10
|
Sprenger A, Wojak JF, Jandl NM, Hertel S, Helmchen C. Predictive mechanisms improve the vestibulo-ocular reflex in patients with bilateral vestibular failure. J Neurol 2014; 261:628-31. [DOI: 10.1007/s00415-014-7276-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 02/06/2014] [Accepted: 02/07/2014] [Indexed: 10/25/2022]
|