Moving in a Moving World: A Review on Vestibular Motion Sickness

Abstract

Motion sickness is a common disturbance occurring in healthy people as a physiological response to exposure to motion stimuli that are unexpected on the basis of previous experience. The motion can be either real, and therefore perceived by the vestibular system, or illusory, as in the case of visual illusion. A multitude of studies has been performed in the last decades, substantiating different nauseogenic stimuli, studying their specific characteristics, proposing unifying theories, and testing possible countermeasures. Several reviews focused on one of these aspects; however, the link between specific nauseogenic stimuli and the unifying theories and models is often not clearly detailed. Readers unfamiliar with the topic, but studying a condition that may involve motion sickness, can therefore have difficulties to understand why a specific stimulus will induce motion sickness. So far, this general audience struggles to take advantage of the solid basis provided by existing theories and models. This review focuses on vestibular-only motion sickness, listing the relevant motion stimuli, clarifying the sensory signals involved, and framing them in the context of the current theories.

Neuro-Ocular Vestibular Dysfunction: An Overlooked Illness

“…This may cause the klutziness in these subjects and the loss of their place during reading. NOVD usually occurs especially in the daytimes because less motion is observed at the sides of the road at night [1][2][3][4][5]. The severity and frequency of the symptoms of NOVD may show a wide variation from patient to patient.…”

“…This is probably caused by the avoiding of the symptomproducing activities in adults. Additionally, adult-onset disease can be caused by a result of head trauma [1][2][3][4][5]. While the brain perceives the position and movements of the body, the inner ear (labyrinth) analyses the data from rotation movements and the movements towards back and forth, sideways and up and down directions.…”

“…In ophthalmological literature, the publications on SSS or NOVD are limited. Already, it is a disorder which has not been exactly understood [1][2][3][4][5].…”

“…However, it is thought that the disorder does not occur without motion detection organs (labyrinth) located in the inner ear while motion sickness can develop blind individuals. Thus, it seems that the visual system might play a lesser role than the inner ear in this disorder [1][2][3][4][5].…”

“…While the brain perceives the position and movements of the body, the inner ear (labyrinth) analyses the data from rotation movements and the movements towards back and forth, sideways and up and down directions. At the same moment, the eyes analyze the position of the body in the environment such as upside down or right side and the data obtained by the observing the direction of formed movement while the sensory receptors in feet, skin, muscles, and joints analyze which part of the body is below and where it touches [1][2][3][4][5].…”