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Three-dimensional kinematical analysis of ocular motor disorders in humans

English title Three-dimensional kinematical analysis of ocular motor disorders in humans
Applicant Straumann Dominik
Number 149521
Funding scheme Project funding (Div. I-III)
Research institution Neurologische Klinik Universitätsspital Zürich
Institution of higher education University of Zurich - ZH
Main discipline Neurophysiology and Brain Research
Start/End 01.11.2013 - 31.10.2016
Approved amount 424'000.00
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All Disciplines (3)

Discipline
Neurophysiology and Brain Research
Neurology, Psychiatry
Pathophysiology

Keywords (7)

neuro-ophthalmology; humans; eye movement disorders; vestibular disorders; neuro-otology; neurology; motion sickness

Lay Summary (German)

Lead
Störungen bei der Empfindung der Selbstbewegung treten unter 3 Bedingungen auf: (1) Die Informationsströme signalisieren unterschiedliche Selbstbewegung, z.B. beim Lesen auf einer Passfahrt. (2) Die Informationsströme stimmen nicht mit der erwarteten Bewegung überein, z.B. beim Betreten einer gestoppten Rolltreppe. (3) Der Körper dreht sich asynchron um mehr als eine Achse, z.B. in Neigezügen, wenn die Bewegungsempfindung nicht mit der effektiven Bewegung übereinstimmt.
Lay summary

Inhalt und Ziel des Forschungsprojekts 

Dieses Projekt betrifft die 3. Art der gestörten Bewegungsempfindung. Die kritischen Parameter, welche zu Reisekrankheit (Kinetose, engl. motion sickness) führen, sollen über die Messung der 3D Augenbewegungen identifiziert werden. Folgende Hypothesen-Abfolge liegt den Experimenten zugrunde: (1) Gewisse Selbstbewegungstrajektorien können vom Hirnstamm / Kleinhirn nicht richtig interpretiert werden. (2) Die Empfindung der Selbstbewegung widerspricht der effektiven Selbstbewegung. (3) Die Differenz zwischen der effektiven Selbstbewegung und reflektorische Augenbewegungen reflektiert den Fehler bei der neuralen Rekonstruktion der Selbstbewegung (“neurale Desorientierung”). 3 Klassen von Experimenten werden durchgeführt: (1) Simulation von verschiedenen Neigezugtechniken. (2) Vergleich von komplexen aktiven (z.B. Treten an Ort) und passiven (gleiche Trajektorien) Selbstbewegungen. (3) Stabilität der Augenposition nach komplexen Oszillation der Unterlage.

 

Wissenschaftlicher und gesellschaftlicher Kontext des Forschungsprojekts

Das Projekt wird Mechanismen aufdecken, wie komplexe Bewegungssignale zu Reisekrankheit führen. Die Erkenntnisse können bei der Steuerung von schnellen Verkehrsmitteln direkt angewendet werden und dienen somit der Prävention von Reisekrankheit.


 

Direct link to Lay Summary Last update: 15.10.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Moving in a Moving World: A Review on Vestibular Motion Sickness.
Bertolini Giovanni, Straumann Dominik (2016), Moving in a Moving World: A Review on Vestibular Motion Sickness., in Frontiers in neurology, 7, 14-14.

Collaboration

Group / person Country
Types of collaboration
Prof. David S. Zee, Department of Neurology, Johns Hopkins Hospital, Baltimore, USA United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Prof. Bernard Cohen, Department of Neurology, Mount Sinai School of Medicine, New York United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Exchange of personnel

Associated projects

Number Title Start Funding scheme
133125 Three-dimensional kinematical analysis of ocular motor disorders in humans 01.10.2010 Project funding (Div. I-III)

Abstract

BACKGROUND: The long-term goal of this research (since 1998) is to better understand disorders of the ocular motor system in humans. The focus of interest is on the three-dimensional (3D) kinematical properties of ocular rotations. During the last three-year period, our research centered on vestibular-evoked potentials of extra-ocular eye muscles and the infantile nystagmus syndrome. For the next grant period, we plan to concentrate on the mechanisms of motion sickness. A detailed analysis of the 3D eye rotations evoked by head movements that cause motion sickness will identify the critical parameters of the underlying vestibular stimulation. WORKING HYPOTHESIS: The overall hypothesis follows this line of arguments: (1) Certain motion trajectories in 3D space elicit vestibular signals that cannot correctly be interpreted by the brainstem (e.g. a canal-otolith conflict). (2) The resulting aberrant self-motion perception is incompatible with physical reality (sensory mismatch theory); this, in turn, causes disorientation and autonomic distress. (3) Kinematical disparities between 3D head movements and vestibular-evoked 3D eye rotations reflect the “false” neural reconstruction of head-in-space movements; thus comparing head motion with eye motion allows quantifying the degree of “neural disorientation”. The 1st major hypothesis derives from our recent observation that passengers on tilting trains are not prone to motion sickness if the roll movements of each car are perfectly synchronized with the yaw velocity changes in the curves. We conjecture that simultaneous rotations about two non-parallel axes (a cross-coupled stimulus) are correctly interpreted by the brain, if rotation about axis 2, e.g. roll, is proportional to the derivative of rotation about axis 1, e.g. yaw (AIM 1). The 2nd major hypothesis derives from a personal observation of the applicant: When head accelerations measured during active movements (applicant going up the stairs) were played back in a passive mode (applicant on a motion simulator), motion sickness occurred. Thus, we postulate that multi-axis rotations of the head are processed differently in the active than in the passive mode. In the active mode, motor efference copy and / or prediction enable the brain to reconstruct head movements correctly, while interpretation errors resulting from cross-coupled rotations cannot be corrected in the passive mode (AIM 2). The 3rd major hypothesis is also based on a personal observation of the applicant: In the tilting train experiments, roll jitter of the cars was different between the reactive (strong jitter) and the predictive (weak jitter) control mode of car tilting. 40 minutes of train travel with strong roll jitter evoked mal de debarquement for a few minutes after the ride, while train rides with weak jitter did not. We propose that exposure to angular jitter transiently reduces the precision of the brain in reconstructing head movements from vestibular signals in the direction of the previous jitter (AIM 3).AIM 1: On a motorized multi-axis turntable, we will simulate cross-coupled yaw and roll movements of tilting trains. By varying the delay between yaw and roll movements, we will explore whether this delay introduces significant kinematic aberrations of the 3D vestibulo-ocular reflex from 3D turntable motion and whether these aberrations correlate with motion sickness and changes in self-motion perception.AIM 2: Angular and linear displacements of the head during active motion of the body, e.g. during the Unterberger-Fukuda stepping test, will be recorded with miniature accelerometers and played back on a motion simulator (hexapod). 3D eye movements during the active and passive modes will be compared. This will identify the mechanisms by which multi-axis vestibular signals are supplemented by the brain during active movement. AIM 3: Subjects, standing on a motion simulator (hexapod), will be exposed to various variations of roll jitter (e.g. frequency, amplitude, regularity, cross-coupling with yaw or lateral acceleration), similar to the jitter on tilting trains, for prolonged periods (e.g. 20 minutes). Before and after exposure, we will assess subjective (e.g. subjective visual vertical, perceived floor movement) and objective (e.g. torsional eye fluctuation, posturography) stability measures in the roll plane to find out whether mal de debarquement symptoms correlate with decreasing precision of eye and body position control.METHODS: This research uses the latest techniques for vestibular stimulation (hexapod motion simulator, motorized multi-axis turntable) and recordings of eye (video-oculography, dual search coil technique), head (3D accelerometers) and body (posturography) motion.EXPECTED VALUE OF THE PROJECT: The proposed project elucidates major vestibular mechanisms of motion sickness by assessing 3D eye rotations evoked by complex head and body movements. This insight will have a direction impact on the modes of position control in fast moving vehicles and the prevention of motion sickness.
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