Gender differences in motion sickness history and susceptibility to optokinetic rotation-induced motion sickness.

Park AH, Hu S.

Department of Psychology, Humboldt State University, Arcata, CA, USA.

PURPOSE: The present study investigated gender differences in motion sickness history and susceptibility to optokinetic rotation-induced motion sickness. METHODS AND RESULTS: The study included two phases. In Phase 1, 485 subjects filled out a survey of previous incidence of motion sickness. Results indicated that women reported significantly greater incidence of feeling motion sickness than did men on buses, on trains, on planes, in cars, and on amusement rides before the age of 12 yr; and on buses, on trains, on planes, in boats, on ships, in cars, on amusement rides, and on swings between the ages of 12 and 25 yr. Women also reported significantly higher incidence of being actually sick than did men on buses before the age of 12 yr and on buses, on ships, and in cars between the ages of 12 and 25 yr. In Phase 2, each of the 47 subjects viewed an optokinetic rotating-drum for 16 min. Subjects' subjective symptoms of motion sickness (SSMS) were obtained during drum rotation. The results showed that there were no significant differences on SSMS scores between men and women. CONCLUSION: Although women reported greater incidence in motion sickness history, women did not differ from men in severity of symptoms of motion sickness while viewing a rotating optokinetic drum.

Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10608604&dopt=Abstract motion sickness




[Comparison between motion sickness induced by reversed vision and that by parallel swing]

[Article in Chinese]

Tong BL, Zhang XY, Gu HG.

Institute of Space Medico-Engineering, Beijing, China.

Objective: To make clear the characteristics of motion sickness induced by reversed vision and to see whether it can be used in motion sickness experiments. Methods: 10 healthy young men experienced walking tests wearing up-down or left-right reversing prisms, and parallel swing test on different days with intervals of 5-7d. Ataxia and motion sickness symptoms induced by walking wearing reversing prisms and those by parallel swing were observed. The reversed vision tolerance index (RVTI) and linear acceleration tolerance index (LATI) were calculated by an empirical formula. Results: Both types of reversing prisms can induce obvious ataxia and motion sickness symptoms. The ataxia is correlative (P<0.05) with the susceptibility to motion sickness. In comparison with symptoms of swing motion sickness, the symptoms of reversed vision motion sickness are not too serious and appear slowly. There are correlativities (P< 0.01) between the susceptibility to motion sickness induced by up-down and left-right reversing prisms. The susceptibilities to motion sickness induced by reversing prisms are not correlative completely with that by swing. Conclusion: Reversed vision test is simple and easy and can be used for simulating space motion sickness or training of adaptation to sensory conflict on the ground.

Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11765772&dopt=Abstract motion sickness




[Recording and analysis of EGG and its application in space medicine]

[Article in Chinese]

Gu HG.

Institute of Space Medico-Engineering, Beijing, China.

To demonstrate the use of EGG in space medicine, especially in motion sickness, biological basis, recording, analysis of EGG used in space medicine, especially in motion sickness studies, were introduced. Several parameters of EGG were related to nausea in motion sickness. It is suggested that EGG can be used in studying nausea symptoms of motion sickness.

Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11765778&dopt=Abstract motion sickness




Active high-frequency vestibulo-ocular reflex and seasickness susceptibility.

Nachum Z, Gordon CR, Shahal B, Spitzer O, Shupak A.

Motion Sickness and Human Performance Laboratory, Israel Naval Medical Institute, Israel Defense Forces Medical Corps, Haifa, Israel.

OBJECTIVES/HYPOTHESIS: The vestibular autorotation test (VAT) examines responses to active head oscillations at frequencies between 2 and 6 Hz in the horizontal and vertical planes while the subject is fixating a visible target. At these frequencies, the vestibulo-ocular reflex (VOR) is the main source of eye movement for ocular stabilization, although other visual and somatosensory information interacts with the response. Because the neural mismatch theory places emphasis on multimodal sensory interactions as the cause of motion sickness, using the VAT, which measures eye movements resulting from vestibular, visual, and, to a certain extent, proprioceptive information and depends on the conscious participation and cooperation of the subject, could be of advantage in evaluating individuals with differing susceptibility to motion sickness. The purpose of the present study was to evaluate high-frequency VOR parameters in seamen at the two extremes of the seasickness susceptibility scale. STUDY DESIGN: Cross-sectional, parallel-group design. METHODS: Participants in the study were 35 healthy male volunteers aged 18 to 23 years, of whom 20 were highly susceptible to seasickness and 15 were nonsusceptible. The vestibulo-ocular reflex was evaluated by the VAT at frequencies ranging from 2.0 to 5.9 Hz. RESULTS: The lag of the vertical phase was significantly higher in the susceptible group. A significant interaction was also found between group and frequency, the vertical phase being significantly higher in the 3.9- to 5.9-Hz range. Although no group effect was detected for the lag of the horizontal phase, there was a significant interaction between group and frequency, the horizontal phase being higher in the susceptible group at 5.5 and 5.9 Hz. No significant group differences were found for horizontal or vertical gain. CONCLUSIONS: The present findings support the contention that the VAT, which measures eye movements resulting from multimodal vestibular, visual, and, to a certain extent, proprioceptive information and depends on the conscious participation and cooperation of the subject, may produce different results in subjects at the two extremes of the seasickness susceptibility scale. Despite the statistical differences that were found, VAT measurements could not be used for practical purposes to categorize individual motion sickness susceptibility.

Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11802059&dopt=Abstract motion sickness




Space motion sickness medications: interference with biomedical parameters.

Vernikos-Danellis J, Winget CM, Leach CS, Rosenblatt LS, Lyman J, Beljan JR.

Biomedical Research Div., NASA, Ames Research Center, Moffett Field, CA 94035, USA.

The possibility that drugs administered to Skylab 3 (SL-3) and 4 (SL-4) crewmen for space motion sickness may have interfered with their biomedical evaluation in space was investigated. Healthy volunteers received combinations of Scopolamine/Dexedrine for four days in regimens similar to those used in these missions. Urine samples, heart rate, body temperature, mood and performance were analyzed for drug-related changes. Twenty-four hour urine samples were analyzed by the same procedures as those used to analyze the flight samples. Hormone concentrations determined included cortisol, epinephrine, norepinephrine, aldosterone and antidiuretic hormone (ADH). In addition, volume, specific gravity, osmolarity, sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), chloride (Cl), inorganic phosphate, uric acid and creatinine were measured. Performance was not affected by the Scopolamine/Dexedrine. The drug combination increased daily mean heart rate (HR) significantly in all the subjects and daily mean rectal temperature (RT) in some of the subjects. A 2-4 hr phase shift in the HR circadian rhythm was also observed which indicates that internal circadian synchrony was disturbed by the drugs. Psychological and subjective evaluation indicated that the subjects could usually identify which days they were given the drugs by an increase in tension and anxiety, decreased patience, restlessness, decreased appetite, difficulty in sleeping and feelings of increased heart rate and body temperature. Urinary electrolytes were not changed significantly by the drug, but marked and significant changes occurred in urine volume and hormone excretion patterns. Scopolamine/Dexedrine caused consistent elevations in urinary cortisol and epinephrine and a transient elevation in ADH. Norepinephrine excretion was decreased, but there was no significant change in aldosterone excretion or in 24 hr urine volume. A comparison of these findings with the first four days of inflight data from the SL-3 and SL-4 missions leads to the conclusion that the dramatic increases in aldosterone excretion during the first three days of spaceflight probably can be directly attributed to weightlessness, whereas the antimotion sickness medication could have substantially contributed to the early increased excretion of epinephrine and cortisol during these missions.

Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11829024&dopt=Abstract motion sickness




Motion sickness susceptibility during rotation at 30 rpm in free-fall parabolic flight.

Graybiel A.

Naval Aerospace Medical Research Laboratory, Pensacola, FL 32508, USA.

Free fall per se whether in parabolic or orbital flight may be regarded as a "partial" motion environment with respect to eliciting motion sickness, requiring an additional component to render this environment "complete" or stressful. Parabolic flight in toto falls in the category of a "complete" motion environment in that some persons became motion sick with head fixed and eyes closed. In the present experiment we selected subjects who were symptom free or nearly symptom free in the KC-135 with head fixed. All tests were conducted with the subject rotating at 30 rpm in a rotating litter chair, and comparisons were made between head-fixed and head-moving conditions (right-left) in the free-fall phase of parabolic flight and under simulated free-fall phases in the laboratory. With head fixed most subjects were insusceptible; with head moving left-right susceptibility was slightly higher in the laboratory than aloft. An additional comparison was made correlating susceptibility in the free-fall phases of parabolic flight with susceptibility to experimental motion sickness in Skylab. In both situations cross-coupled angular accelerations were generated by executing head and body movements out of the plane of rotation. In parabolic flight 9 of 15 subjects reached an endpoint just short of frank motion sickness. In the Skylab workshop all eight of the astronauts tested were symptom free at the end of the test. The explanation for the difference in susceptibility rests in two factors: (1) Basic susceptibility in free fall is lower than on the ground, and (2) in Skylab the astronauts who needed to adapt had achieved this goal prior to the first test on Mission-Day 8.

Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11831246&dopt=Abstract motion sickness




Individual differences in susceptibility to motion sickness among six Skylab astronauts.

Graybiel A, Miller EF 2nd, Homick JL.

Biological Sciences Department, Naval Aerospace Medical Research Laboratory, Pensacola, Florida 32512, USA.

One of the Skylab experiments dealt with motion sickness, comparing susceptibility in the workshop aloft with susceptibility preflight and postflight. Tests were conducted on and after mission-day 8 (MD 8) by which time the astronauts were adapted to working conditions. Stressful accelerations were generated by requiring the astronauts, with eyes covered, to execute standardized head movements (front, back, left, and right) while in a chair that could be rotated at angular velocities up to 30 rpm. The selected endpoint was either 150 discrete head movements or a very mild level of motion sickness. In all rotation experiments aloft, the five astronauts tested (astronaut 1 did not participate) were virtually symptom free, thus demonstrating lower susceptibility aloft than in preflight and postflight tests on the ground when symptoms were always elicited. Inasmuch as the eyes were covered and the canalicular stimuli were the same aloft as on the ground, it would appear that lifting the stimulus to the otolith organs due to gravity was an important factor in reducing susceptibility to motion sickness even though the transient stimuli generated under the test conditions were substantial and abnormal in pattern. Some of the astronauts experienced motion sickness under operational conditions aloft or after splashdown, but attention is centered chiefly on symptoms manifested in zero gravity. None of the Skylab-II crew (astronauts 1 to 3) was motion sick aloft. Astronaut 6 of the Skylab-III crew (astronauts 4 to 6) experienced motion sickness within an hour after transition into orbit; this constitutes the earliest such diagnosis on record under orbital flight conditions. The eliciting stimuli were associated with head and body movements, and astronaut 6 obtained relief by avoiding such movements and by one dose of the drug combination 1-scopolamine 0.35 mg + d-amphetamine 5.0 mg. All three astronauts of Skylab-III experienced motion sickness in the workshop where astronaut 6 was most susceptible and astronaut 4, least susceptible. The higher susceptibility of SL-III crewmen in the workshop, as compared with SL-II crewmen, may be attributable to the fact that they were based in the command module less than one-third as long as SL-II crewmen. The unnatural movements, often resembling acrobatics, permitted in the open spaces of the workshop revealed the great potentialities in weightlessness for generating complex interactions of abnormal or unusual vestibular and visual stimuli. Symptoms were controlled by body restraint and by drugs, but high susceptibility to motion sickness persisted for 3 days and probably much longer; restoration was complete on MD 7. From the foregoing statements it is clear that on and after MD 8 the susceptibility of SL-II and SL-III crewmen to motion sickness under experimental conditions was indistinguishable. The role played by the acquisition of adaptation effects prior to MD 8 is less clear and is a subject to be discussed.

Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11841091&dopt=Abstract motion sickness




The menstrual cycle and susceptibility to coriolis-induced sickness.

Cheung B, Heskin R, Hofer K, Gagnon M.

Aerospace Life Support Section, Defence and Civil Institute of Environmental Medicine, 1133 Sheppard Ave. W, Toronto, Ontario, Canada. bob.cheung dciem.dnd.ca

Survey studies on motion sickness susceptibility suggest that females tend to report greater severity in illness and higher incidence of vomiting than males. Menstruation is said to be a contributing factor. A recent study suggested that females were least susceptible to seasickness during ovulation in a "round the world" yacht race. Sixteen subjects (18-36 years old) were exposed to Coriolis cross-coupling stimulation in the laboratory. They were tested once during permenstruation (Day 1-5), ovulation (Day 12-15) and premenstruation (Day 24-28), based on a normalized 28-day cycle, in a randomised design. Physiological measurements of motion sickness included forearm and calf cutaneous blood flow. Subjective evaluation of sickness symptoms was based on Graybiel's diagnostic criteria and Golding's rating method. Our results indicated that under controlled laboratory conditions, different phases of the menstrual cycle appear to have no influence on subjective symptoms of motion sickness or on cutaneous blood flow increase in the forearm and calf. The lack of commonality between the types and levels of hormones that are released during motion sickness and those that are involved in different menstrual phases appears to support our findings.

Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11847456&dopt=Abstract motion sickness