Correlation between anxiety and chronic motion sensitivity.

BACKGROUND: Chronic motion sensitivity (CMS) is a combination of autonomic symptoms provoked by exposure to motion. The correlation between anxiety and CMS is not yet well understood. OBJECTIVES: 1) To compare median anxiety levels between young adults with and without CMS. 2) To examine the effect of anxiety on postural stability with immersion virtual reality. 3) To compare anxiety levels between sexes. METHODS: Participants included 60 adults (20-40 years), with and without CMS. After determining their current and general anxiety levels, postural stability was measured. RESULTS: There were significant differences in median (minimum, maximum) state- and trait-anxiety scores between participants with and without CMS, but no significant differences in median state- and trait-anxiety scores between males and females with CMS. There was a significant inverse relationship between state- and trait-anxiety scores and postural stability (ρ= -0.28, p = 0.03, and ρ= -0.32, p = 0.01, respectively). The stepwise regression analysis showed the Motion Sickness Susceptibility Questionnaire-Short Form score to be the only variable contributing significantly to postural stability (R2 = 26.2%; t = -4.5, p < 0.001). CONCLUSIONS: Young adults with CMS are more anxious, although anxiety does not contribute to postural stability in this group. Anxiety levels do not appear to differ between young adult males and females with CMS.

Effects of head motion on postural stability in healthy young adults with chronic motion sensitivity.

BACKGROUND: Motion sensitivity, or motion sickness, is common in modern vehicular and visually stimulating environments. Several studies have shown a relationship between motion sensitivity and decreased postural stability. We aimed to evaluate the effects of head motion (horizontal and vertical) on postural stability in healthy adults with and without chronic motion sensitivity (CMS). METHODS: Sixty healthy adult men and women (age, 20-40 years) with CMS (CMS group, n = 30) and without CMS (non-CMS group, n = 30) participated in the study. Postural stability was assessed during three conditions (static, horizontal head motion, and vertical head motion) using computerized dynamic posturography. Group and condition-related differences in equilibrium scores were evaluated. RESULTS: There was no significant group x condition interaction (F2,114 = 0.9, partial ƞ2 = 0.04, p = 0.35). However, significant condition-related differences in equilibrium scores were observed (F2,114 = 26.4, partial ƞ2 = 0.31, p < 0.001). Equilibrium scores were significantly worse in the horizontal and vertical head motion conditions compared to those in the static condition (p < 0.001), but were comparable in vertical and horizontal head motion conditions (p = 0.27). CONCLUSIONS: Postural stability was lower in the horizontal and vertical conditions compared to the static condition. However, horizontal and vertical head motions had comparable effects on postural stability in both CMS and non-CMS groups, contrary to our expectations.

Effect of visual input on postural stability in young adults with chronic motion sensitivity: A controlled cross-sectional study.

BACKGROUND: Chronic motion sensitivity (CMS) has been defined as a feeling of un-wellness elicited by either actual or perceived motion. CMS is a common condition and is more prevalent in females than in males. In addition to a variety of symptoms, young adults with CMS have less postural stability than those without CMS. OBJECTIVE: To determine whether dependence on visual cues for postural stability is different between young adults with and without CMS, and whether it differs by gender within each group. METHODS: Sixty young adults (30 females and 30 males) were assigned to one of two groups (CMS or non-CMS) using the Motion Sickness Susceptibility Questionnaire-Short Form. Postural stability was measured for all participants using the Bertec Balance Advantage-Computerized Dynamic Posturography with Immersion Virtual Reality. RESULTS: A significant difference was found in mean postural stability scores during immersion virtual reality between the CMS and non-CMS groups (p < 0.001); however, no significant difference was shown in mean postural stability between males and females within the CMS and non-CMS groups (p = 0.10 and p = 0.97, respectively). CONCLUSION: The results suggest that young adults with CMS are over-reliant on visual cues for postural stability, and that visual dependence is not influenced by gender.