Motion sickness: acquisition and retention of adaptation effects compared in three motion environments.

Graybiel A, Lackner JR.

A sharp distinction should be made between symptoms of motion-sickness per se and phenomena inferred from the symptomatology, which include rates of acquisition and decay of adaptation effects. Foreknowledge of these "derived phenomena" are valuable if it can be shown that they hold true for virtually any motion environment. Recently, we have developed a sudden-stop vestibulovisual interaction test for measuring susceptibility to motion sickness (1). The test procedure involves four successive assessments that provide not only an index of susceptibility to motion sickness but also the rates of acquisition and decay of adaptation effects. The 14 subjects participating in this test had previously served as subjects in parabolic flight experiments and seven of them had also taken part in the assessment of antimotion-sickness remedies in a slow rotation room. The present report examines whether their rates of acquisition and decay of adaptation to stressful motion represent consistent general features of their responses across motion environments. From these comparisons, it appears that an individual's rates of acquiring and losing adaptation are quite consistent in very different situations. The pattern of results also suggests modifications of the sudden-stop vestibulovisual test that should increase its effectiveness as a motion-sickness screening procedure, both for orbital flight and for terrestrial conditions.

Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6847566&dopt=Abstract motion sickness




Childhood migraine and motion sickness.

Barabas G, Matthews WS, Ferrari M.

The incidence of motion sickness among 222 children in four diagnostic categories--migraine, nonmigraine headaches, seizure disorders, and learning disabilities--was compared. Motion sickness was found to be an associated feature in 45% of the cases of childhood migraine, in contrast to a 5% to 7% incidence in the other groups. Therefore, it is suggested that motion sickness be regarded as an additional reliable minor criterion in the diagnosis of childhood migraine. Hypotheses of common central and peripheral mechanisms underlying both conditions are offered.

Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6866603&dopt=Abstract motion sickness




Physiological and behavioral effects of tilt-induced body fluid shifts.

Parker DE, Tjernstrom O, Ivarsson A, Gulledge WL, Poston RL.

This paper addresses the "fluid shift theory" of space motion sickness. The primary purpose of our research was the development of procedures to assess individual differences in response to rostral body fluid shifts on earth. Experiment I examined inner ear fluid pressure changes during head-down tilt in intact human beings. Tilt produced reliable changes. Differences among subjects and between ears within the same subject were observed. Experiment II examined auditory threshold changes during tilt. Tilt elicited increased auditory thresholds, suggesting that sensory depression may result from increased inner ear fluid pressure. Additional observations on rotation magnitude estimation during head-down tilt, which indicate that rostral fluid shifts may depress semicircular canal activity, are briefly described. The results of this research suggest that the inner ear pressure and auditory threshold shift procedures could be used to assess individual differences among astronauts prior to space flight. Results from the terrestrial observations could be related to reported incidence/severity of motion sickness in space and used to evaluate the fluid shift theory of space motion sickness.

Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6870733&dopt=Abstract motion sickness




Sensory conflict theory of space motion sickness: an anatomical location for the neuroconflict.

Kohl RL.

Most investigators understand sensory conflict to mean a discontinuity between either visual, proprioceptive, and somatosensory input, or semicircular canal and otolith input. Few hypotheses have attempted to define specific physiological mechanisms linking the conflict with the sickness. Suggestions that the theory be renamed the neural mismatch theory allow for the possibility that central integrative mechanisms are involved in interpreting the significance of the sensory environment and that the conflict between visual or vestibular input systems or between separate components of the vestibular system is of secondary importance to mismatch occurring between ongoing sensory experience and long-term memory. This paper describes the role of the limbic system in integration of sensory information and long-term memory, in the expression of the symptoms of motion sickness, and the impact of anti-motion sickness drugs and stress hormones on limbic system function. The limbic system may be the neural mismatch center of the brain.

Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6870740&dopt=Abstract motion sickness




Vision and motion sickness.

Jay WM, Jay MS.

The development of motion sickness appears intimately related to the visual system. The Sensory Rearrangement Theory states that situations which promote motion sickness are characterized by a condition in which the motion signals transmitted by the eyes, vestibular system, and the nonvestibular proprioceptors are at variance as to what was expected previously. The evolutionary significance of motion sickness rests in its linkage to an early warning system to avoid poisoning. Vision is capable of aiding in the development of suppression of motion sickness. Therapy of motion sickness includes posture, restriction of head movement, visual manipulations, concurrent activity, drugs, and adaptation.

Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6977635&dopt=Abstract motion sickness




Space adaptation syndrome: multiple etiological factors and individual differences.

Lackner JR, DiZio P.

Brandeis University, Waltham, Massachusetts, USA.

Space motion sickness is a significant operational concern in the American and Soviet space programs. Nearly 70% of all astronauts and cosmonauts are affected to some degree during their first several days of flight. It is now beginning to appear that space motion sickness like terrestrial motion sickness is the consequence of multiple etiological factors. As we come to understand basic mechanisms of spatial orientation and sensory-motor adaptation we can begin to predict etiological factors in different motion environments. Individuals vary greatly in the extent to which they are susceptible to these different factors. However, individuals seem to be relatively self-consistent in terms of their rates of adaptation to provocative stimulation and their retention of adaptation. Attempts to relate susceptibility to motion sickness during the microgravity phases of parabolic flight maneuvers to vestibular function under 1G and 0G test conditions are described.

Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11540716&dopt=Abstract motion sickness




A statistical examination of three approaches for predicting motion sickness incidence.

Smith DE.

This paper examines three approaches which have been suggested for predicting motion sickness incidence (MSI) for actual or simulated broadband ship motion. Although only a small amount of empirical MSI data exists for motion other than that produced by a single sinusoid, this data provides strong statistical evidence that two approaches based on single sinusoid models fail to produce accurate predictions. Statistical judgments about a least-squares weighting approach must be reserved until enough data exists to provide an adequate test. In view of these results, it must be concluded that much empirical research remains to be done in order to develop a reasonably accurate method of predicting motion sickness incidence for broadband motion.

Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=7059332&dopt=Abstract motion sickness




[Reaction to decreased circulating blood volume in persons subject and resistant to motion sickness (airsickness)]

[Article in Russian]

Isupov VG, Maksimov DG, Poliakov BI.

The study of 54 healthy male test subjects demonstrated significantly different responses of motion sickness susceptible and resistant people to 10-minute occlusion of their femoral veins. The changes in limb rheograms, as well as heart rate and stroke volume indicated that in motion sickness susceptible subjects the circulating blood volume in the upper body decreased, whereas in motion sickness resistant subjects it remained unaltered or increased in response to the occlusion.

Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=7098410&dopt=Abstract motion sickness