John F. Golding

Motion sickness susceptibility questionnaire revised and its relationship to other forms of sickness

The Reason and Brand Motion Sickness Susceptibility Questionnaire (MSSQ) has remained unchanged for a quarter of a century. The primary aims of this investigation were to improve the design of the MSSQ, simplify scoring, produce new adult reference norms, and analyse motion validity data. We also considered the relationship of sickness from other nonmotion causes to the MSSQ. Norms and percentiles for a sample of 148 subjects were almost identical to the original version of this instrument. Reliability of the whole scale gave a Cronbachs standardised item alpha of 0.86, the correlation between Part A (child) and Part B (adult) was r = 0.65 (p < 0.001), and test-retest reliability may be assumed to be better than 0.8. Predictive validity of the MSSQ for motion sickness tolerance using laboratory motion devices averaged r = 0.45. Correlation between MSSQ and other sources of nausea and vomiting in the last 12 months, excluding motion sickness itself, was r = 0.3 (p < 0.001), migraine was the most important contributor to this relationship. In patients (n = 101) undergoing chemotherapy, there were significant correlations between MSSQ and chemotherapy-induced nausea and vomiting. Migraine also appeared as a predictor of chemotherapy-induced sickness. It was concluded that the revised MSSQ can be used as a direct replacement of the original version. The relationship between motion sickness susceptibility and other causes of sickness, including migraine and chemotherapy, points to the involvement of the vestibular system in the response to nonmotion emetogenic stimuli. Alternatively, this relationship may reflect individual differences in excitability of the postulated final common emetic pathway.

Mental and physical health in students: The role of economic circumstances

Objectives. To investigate the relationship between the physical, social and psychological health of students and their financial circumstances. Design. A survey design was used. Methods. An opportunity sample of 482 university students from two London universities (one old and one new) completed a questionnaire providing information on demographic characteriscics, financial circumstances, smoking, drug and alcohol use. Physical and psychological well-being were assessed using a 14-item inventory of physical symptoms, the SF-36 and General Health Questionnaire (GHQ-12). Results. All sub-scales of the SF-36 (except Physical Functioning) and the GHQ indicated levels of health significantly below population norms. Poorer mental health was related to longer working hours outside university and difficulty paying bills. Those who had considered abandoning study for financial reasons had poorer mental health, social functioning, vitality and physical health and were also heavier smokers. Being in debt was associated with knowing people involved in prostitution, crime or drug dealing to help support themselves financially. Conclusion. Results suggest that the financial circumstances of students may be having an adverse impact on their health.

Vestibular Perception following Acute Unilateral Vestibular Lesions

Little is known about the vestibulo-perceptual (VP) system, particularly after a unilateral vestibular lesion. We investigated vestibulo-ocular (VO) and VP function in 25 patients with vestibular neuritis (VN) acutely (2 days after onset) and after compensation (recovery phase, 10 weeks). Since the effect of VN on reflex and perceptual function may differ at threshold and supra-threshold acceleration levels, we used two stimulus intensities, acceleration steps of 0.5°/s2 and velocity steps of 90°/s (acceleration 180°/s2). We hypothesised that the vestibular lesion or the compensatory processes could dissociate VO and VP function, particularly if the acute vertiginous sensation interferes with the perceptual tasks. Both in acute and recovery phases, VO and VP thresholds increased, particularly during ipsilesional rotations. In signal detection theory this indicates that signals from the healthy and affected side are still fused, but result in asymmetric thresholds due to a lesion-induced bias. The normal pattern whereby VP thresholds are higher than VO thresholds was preserved, indicating that any ‘perceptual noise’ added by the vertigo does not disrupt the cognitive decision-making processes inherent to the perceptual task. Overall, the parallel findings in VO and VP thresholds imply little or no additional cortical processing and suggest that vestibular thresholds essentially reflect the sensitivity of the fused peripheral receptors. In contrast, a significant VO-VP dissociation for supra-threshold stimuli was found. Acutely, time constants and duration of the VO and VP responses were reduced – asymmetrically for VO, as expected, but surprisingly symmetrical for perception. At recovery, VP responses normalised but VO responses remained shortened and asymmetric. Thus, unlike threshold data, supra-threshold responses show considerable VO-VP dissociation indicative of additional, higher-order processing of vestibular signals. We provide evidence of perceptual processes (ultimately cortical) participating in vestibular compensation, suppressing asymmetry acutely in unilateral vestibular lesions.

Visual Dependency and Dizziness after Vestibular Neuritis

Symptomatic recovery after acute vestibular neuritis (VN) is variable, with around 50% of patients reporting long term vestibular symptoms; hence, it is essential to identify factors related to poor clinical outcome. Here we investigated whether excessive reliance on visual input for spatial orientation (visual dependence) was associated with long term vestibular symptoms following acute VN. Twenty-eight patients with VN and 25 normal control subjects were included. Patients were enrolled at least 6 months after acute illness. Recovery status was not a criterion for study entry, allowing recruitment of patients with a full range of persistent symptoms. We measured visual dependence with a laptop-based Rod-and-Disk Test and severity of symptoms with the Dizziness Handicap Inventory (DHI). The third of patients showing the worst clinical outcomes (mean DHI score 36–80) had significantly greater visual dependence than normal subjects (6.35° error vs. 3.39° respectively, p = 0.03). Asymptomatic patients and those with minor residual symptoms did not differ from controls. Visual dependence was associated with high levels of persistent vestibular symptoms after acute VN. Over-reliance on visual information for spatial orientation is one characteristic of poorly recovered vestibular neuritis patients. The finding may be clinically useful given that visual dependence may be modified through rehabilitation desensitization techniques.

Seasonality, social zeitgebers and mood variability in entrainment of mood: Implications for seasonal affective disorder

BACKGROUND Seasonal variations in mood (seasonality) appear to be entrained to light, a physical zeitgeber. We hypothesised that people high in seasonality may be responsive to a range of zeitgebers, because of greater mood variability. We investigated whether the moods of people high in seasonality were more strongly entrained to the calendar week, a social zeitgeber, and whether any such effect was dependent on variability of mood. METHODS 53 participants (14 male, 39 female; overall mean age=30) completed a daily mood report, over 56 consecutive days. Participants also completed the Seasonality Score Index (SSI) of the Seasonal Pattern Assessment Questionnaire. Each participants time series of daily mood was analysed by spectral analysis to quantify the strength of their weekly mood cycle. RESULTS Participants with high SSI scores (> or =11) had significantly stronger weekly mood cycles than those with low SSI scores (<11), and significantly greater variability in mood. Covarying for mood variability reduced the difference between high and low SSI groups in mean strength of weekly mood cycle to non-significance. LIMITATIONS The time series of moods obtained was relatively short, and moods among high seasonal participants may have been affected by seasonal weather variability. CONCLUSIONS People high in seasonality appear to be more responsive to external zeitgebers, and this could be linked to their greater variability in mood. The integration of research on mood variability with research on SAD appears to be warranted.

Behavioral Methods of Alleviating Motion Sickness: Effectiveness of Controlled Breathing and a Music Audiotape

BACKGROUND Behavioral countermeasures for motion sickness would be advantageous because of the side effects of antiemetic drugs, but few alternative treatments are available. The objective of this study was to compare the effectiveness of controlling breathing and listening to a music audiotape designed to reduce motion sickness symptoms, on increasing tolerance to motion-induced nausea. METHOD Twenty-four healthy subjects were exposed to nauseogenic Coriolis stimulation on a rotating turntable under three conditions: whilst focusing on controlling breathing; listening to a music audiotape; or without intervention (control). The three conditions were performed by each subject according to a replicated factorial design at 1-week intervals at the same time of day. Ratings of motion sickness were obtained every 30 seconds. Once a level of mild nausea was reached subjects commenced controlling breathing or listened to the music audiotape. Motion was stopped after the onset of moderate nausea. RESULTS Mean (+/- SD) motion exposure time in minutes tolerated before the onset of moderate nausea was significantly longer (p <.01) for controlling breathing (10.7 +/- 5.6 min) and longer (p <.01) for music (10.4 +/- 5.6 min) compared with control (9.2 +/- 5.9 min). CONCLUSIONS Both controlling breathing and the music audiotape provided significant protection against motion sickness and with similar effectiveness. These nonpharmacologic countermeasures are only half as effective as standard doses of anti-motion sickness drugs, such as oral scopolamine; however, they are easy to implement and free of side effects.

Pathophysiology and treatment of motion sickness

PURPOSE OF REVIEW Motion sickness remains bothersome in conventional transport and is an emerging hazard in visual information technologies. Treatment remains unsatisfactory but advances in brain imaging, neurophysiology, and neuropharmacology may provide insights into more effective drug and behavioural management. We review these major developments. RECENT FINDINGS Recent progress has been in identifying brain mechanisms and loci associated with motion sickness and nausea per se. The techniques have included conventional neurophysiology, pathway mapping, and functional MRI, implicating multiple brain regions including cortex, brainstem, and cerebellum. Understanding of the environmental and behavioural conditions provocative of and protective against motion sickness and how vestibular disease may sensitize to motion sickness has increased. The problem of nauseogenic information technology has emerged as a target for research, motivated by its ubiquitous applications. Increased understanding of the neurophysiology and brain regions associated with motion sickness may provide for more effective medication in the future. However, the polysymptomatic nature of motion sickness, high interindividual variability, and the extensive brain regions involved may preclude a single, decisive treatment. SUMMARY Motion sickness is an emerging hazard in information technologies. Adaptation remains the most effective countermeasure together with established medications, notably scopolamine and antihistamines. Neuropharmacological investigations may provide more effective medication in the foreseeable future.

Motion sickness susceptibility in healthy subjects and vestibular patients: effects of gender, age and trait-anxiety

Several studies have suggested that anxiety may play a role in motion sickness susceptibility (MSS) variability. This study aimed to assess motion sickness susceptibility in healthy subjects and chronic vestibular patients and to investigate its relationship to gender, age and trait-anxiety. Healthy subjects (n=167) and chronic dizzy patients with various vestibulopathies (n=94), aged from 20 to 92 years old, were asked to complete Motion Sickness Susceptibility questionnaire (MSSQ) and trait-anxiety questionnaire (STAI-B). When patients were divided into those who had vestibular loss (n=51) vs. patients without vestibular loss (n=43), the MSSQ scores (mean ± SD) for patients with vestibular loss (18.8 ± 30.9) were lower than healthy subjects (36.4 ± 34.8), who were lower than vestibular patients without vestibular loss (59.0 ± 39.7). These significant differences could not be explained by gender, age, trait-anxiety, or interaction. Women had higher MSS than men, and MSS declined with age for healthy subjects and vestibular patients. The overall relationship between anxiety and MSS scores was weak and only reached significance in healthy subjects. These results support the conclusion that the vestibular system is heavily involved in MSS and that trait-anxiety may play a role in MSS but only in healthy subjects.

Cognitive impairment by spatial disorientation.

INTRODUCTION Maintaining spatial orientation is a biological imperative. When orientation is threatened, attention resources are diverted to regaining orientation, possibly to the detriment of attention required by concurrent tasks. Hence, a factor in aviation mishaps may be the negative impact of disorientation on concurrent performance, such as interpreting instruments. We examined how subjects learn to manage the impact of acute disorienting stimuli on concurrent spatial cognitive tasks. METHODS Subjects performed the Manikin (MAN) and Choice Reaction Time (CRT) tests under three disorienting experiments: i) after self-controlled head rolls, N = 16; ii) during rotation of the background field of view, N = 12; and iii) after head movements provoking Coriolis during body rotation in yaw, N = 6. RESULTS Number correct and reaction times on the MAN task were negatively affected by each type of disorientation only when the task was performed in the presence of disorienting motion presented early in the experimental session. Later in the session, subjects learned to attain best performance levels irrespective of disorientation. Performance on the CRT task, which has good stimulus response compatibility with little high order processing, was unaffected. The slight symptoms of malaise provoked by disorientation did not interfere with performance in experiments (i) and (ii) but more severe symptoms in (iii) correlated with loss of performance. CONCLUSION Our studies suggest that the ability to maintain a high level of cognitive performance is susceptible to impairment when novel circumstances of disorientation are encountered. Extensive practice on particular tasks protects against encounters with novel disorientation. Once disorientation is identified, its potential impact on multitasking may be quarantined despite disorientation symptoms. The results indicate the need for over-training on tasks and experience with a wide variety of disorientation scenarios.

Effect of Breathing Supplemental Oxygen on Motion Sickness in Healthy Adults

OBJECTIVE To compare the effects of breathing supplemental oxygen vs air on alleviating motion sickness in healthy adults. SUBJECTS AND METHODS Between April and July 2002, 20 healthy subjects were exposed to a provocative motion on 2 occasions (1-week interval) according to a randomized, counterbalanced, crossover design. During motion, subjects rated their nausea (1, no symptoms, to 4, moderate nausea) every 30 seconds. Once mild nausea occurred, subjects began breathing supplemental oxygen or air through a face mask. Motion ceased when moderate nausea occurred, but subjects continued breathing study gases for 5 minutes while recovering. Recovery was assessed for 20 minutes after motion. RESULTS There were no significant differences in the rate of increase in symptom severity or the rate of recovery between the 2 conditions. CONCLUSION Breathing supplemental oxygen had no advantage over breathing air in reducing motion sickness in healthy adults.