The Relative Roles of the Otolith Organs and Semicircular Canals in Producing Space Motion Sickness

Migraine is associated with enhanced motion sickness susceptibility and can cause episodic vertigo [vestibular migraine (VM)], but the mechanisms relating migraine to these vestibular symptoms remain uncertain. We tested the hypothesis that the central integration of rotational cues (from the semicircular canals) and gravitational cues (from the otolith organs) is abnormal in migraine patients. A postrotational tilt paradigm generated a conflict between canal cues (which indicate the head is rotating) and otolith cues (which indicate the head is tilted and stationary), and eye movements were measured to quantify two behaviors that are thought to minimize this conflict: suppression and reorientation of the central angular velocity signal, evidenced by attenuation (“dumping”) of the vestibuloocular reflex and shifting of the rotational axis of the vestibuloocular reflex toward the earth vertical. We found that normal and migraine subjects, but not VM patients, displayed an inverse correlation between the extent of dumping and the size of the axis shift such that the net “conflict resolution” mediated through these two mechanisms approached an optimal value and that the residual sensory conflict in VM patients (but not migraine or normal subjects) correlated with motion sickness susceptibility. Our findings suggest that the brain normally controls the dynamic and spatial characteristics of central vestibular signals to minimize intravestibular sensory conflict and that this process is disrupted in VM, which may be responsible for the enhance motion intolerance and episodic vertigo that characterize this disorder.

Download Full-text

Space Motion Sickness Status Report

10.4271/860923 ◽

1986 ◽

Author(s):

Frank Kutyna

Keyword(s):

Motion Sickness ◽

Status Report ◽

Space Motion Sickness ◽

Space Motion

Download Full-text

A re-investigation of the role of utricular asymmetries in Space Motion Sickness

Journal of Vestibular Research ◽

10.3233/ves-2011-0400 ◽

2011 ◽

Vol 21 (3) ◽

pp. 141-151 ◽

Cited By ~ 5

Author(s):

S.A.E. Nooij ◽

R. Vanspauwen ◽

J.E. Bos ◽

F.L. Wuyts

Keyword(s):

Motion Sickness ◽

Space Motion Sickness ◽

Space Motion

Download Full-text

Influence of Inosine on Cerebral Hemodynamics in Space Motion Sickness in Experimental Animals

Central Nervous System Agents in Medicinal Chemistry ◽

10.2174/1871524921666210428111827 ◽

2021 ◽

Vol 21 ◽

Author(s):

Asie N. Useinova ◽

Vitalii Kaliberdenko ◽

Igor D. Sapegin ◽

Shanmugaraj Kulanthaivel ◽

Michael V. Shterenshis ◽

...

Keyword(s):

Blood Flow ◽

Motion Sickness ◽

Vascular Reactivity ◽

Visual Stimulation ◽

Cerebrovascular Disorders ◽

Cerebral Vessels ◽

Local Blood Flow ◽

Experimental Animals ◽

Space Motion Sickness ◽

Space Motion

Background: Motion sickness occurs worldwide in healthy individuals regardless of age, ethnicity, or gender. It is an acute disorder, it can also present as a chronic disorder in some individuals. Motion sickness not only includes vomiting and nausea, besides this, it includes other features such as pallor of varying degrees, cold sweating, headache, drowsiness, increased salivation, and cranial pain which is severe. Some of the other assessment scales can interpret sickness on exposure to virtual or visual stimulation and while travelling in different types of transport. Aim: The aim our research is to study the effect of the drug on the level of blood flow and vascular reactivity of cerebral vessels when simulating changes in cerebral circulation in terrestrial conditions characteristic of hypogravity. Methods: Chronic experiments were performed on non-anesthetized rabbits with large hemispheres, thalamus and hypothalamus were implanted with the needle-platinum electrodes 150 mm in diameter in the cortex, and local blood flow and vascular reactivity were recorded accordingly. Cerebrovascular disturbances were modeled using a MSAOP (motion sickness of animals in the anti-orthostatic position) with an inclined angle of 45 ° for 2 hours. Local blood flow (BF) was measured in ml/min/100 g of tissue by the method of registration of hydrogen clearance. The vasodilator coefficient of reactivity (CrCO2) was calculated by the ratio of BF against the background of inhalation of a mixture of 7% CO2 with air to the initial BF; vasoconstrictor - in relation to BF on the background of inhalation of 100% O2 to the initial BF (CrO2). A series of experiments was carried out with different routes of drug administration: First, inosine was administered intravenously at a dose of 5 mg/kg immediately before the start of SMS modeling, Same dose per oral was administered 30 minutes before the start of exposure. As a control, we used the results of experimental animals under similar conditions without the administration of the drugs. Results: Inosine has pronounced protective properties in cerebrovascular disorders on the background of space motion sickness (SMS) modeling, which is manifested by normalization of BF and restoration of compensatory reactions of cerebral vessels. In the mechanism of cerebroprotective action of inosine, it is able to correct the metabolic processes which plays an important role and helps to increase the compensatory capabilities and functional stability of the cerebrovascular system under gravitational influences. Conclusion: When using inosine per orally, the effects are more pronounced than when administered intravenously, which should be taken into account when using it for the prevention of cerebrovascular disorders in extreme conditions.

Download Full-text