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Introduction: Persistent postural-perceptual dizziness (PPPD) and vestibular migraine (VM) share symptoms of visual vertigo and motion sickness that can be confusing for clinicians to distinguish. We compare the severity of these symptoms and dynamic subjective visual vertical (dSVV) in these two common vestibular conditions., Method: Twenty-nine patients with PPPD, 37 with VM, and 29 controls were surveyed for subjective symptoms using the visual vertigo analogue scale (VVAS) and motion sickness susceptibility questionnaire during childhood (MSA) and the past 10 years (MSB). dSVV is a measure of visual dependence measures perception of verticality against a rotating background (5 deg./s)., Results: VVAS revealed contextual differences for dizziness between those with PPPD and VM. Ratings of visual vertigo were most severe in PPPD, less in VM, and mild in controls (VVAS PPPD 27.1, VM 11.2, control 4.6, p < 0.001). MSA was more severe in VM than in PPPD or control (12.8 vs 7.6 vs 8.5, p = 0.01). MSB was more severe in VM than controls (MSB score 12.9 VS 8.1 p = 0.009) but was not different than PPPD (MSB score 10.0, p = 0.10). dSVV alignment was similar among the three groups (p = 0.83). Both VM and PPPD groups had greater simulator sickness than controls after completing the dSVV., Conclusions: Patients with PPPD report more visual vertigo than those with VM, but a history of motion sickness as a child is more common in VM. Additionally, the environmental context that induces visual vertigo is different between PPPD and VM., Competing Interests: Declaration of competing interest None of the authors have competing interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objective: To find out if motion sickness susceptibility (MSS) of vestibular migraine (VM) patients and migraine only (MO) patients can be reliably detected with a single simple question: "Can you read while travelling in a car without getting motion sick?"., Method: Ninety-two definite VM and 58 MO patients and 74 healthy control (HC) subjects were asked about their MSS and about being able to read while riding in a car without becoming motion sick. A Motion Sickness Susceptibility Questionnaire (MSSQ-Short) including childhood (MSA), adulthood (MSB) and total (MST) parts was also administered to all participants. ROC curves of MSSQ-Short were prepared for "not being able to read in a car" as the gold standard., Results: Mean MSA scores were significantly higher in both VM and MO patients than in HCs (p < 0.001), but their scores were not significantly different (p = 0.171). Mean MSB and MST scores were significantly higher in VM than in MO patients (p < 0.001) and both VM and MO patients had significantly higher scores than HCs (p < 0.001). MSA scores were significantly higher than MSB scores in MO patients (p < 0.001). All sections of the questionnaire were associated with high area-under-curve values for MSS detected by the question about being able to read in a car without becoming motion sick., Conclusion: We propose that all migraine patients could have the same level of MSS in childhood but MO patients are able to compensate over years, but VM patients are not. A quick way to determine MSS is to ask about the ability to read without becoming motion sickness while riding a car., (Copyright © 2023 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier España S.L.U. All rights reserved.)

Background: Migraine and vestibular migraine are disorders associated with a heightened motion sensitivity that provoke symptoms of motion-induced nausea and motion sickness. VM affects ∼3% of adults in the USA and affects three-fold more women than men. Triptans (selective serotonin receptor agonists) relieve migraine pain but lack efficacy for vertigo. Murine models of photophobia and allodynia have used injections of calcitonin gene-related peptide (CGRP) or other migraine triggers, such as sodium nitroprusside (SNP), to induce migraine sensitivities in mice to touch and light. Yet, there is limited research on whether these triggers affect motion-induced nausea in mice, and whether migraine blockers can reduce these migraine symptoms. We hypothesized that systemic delivery of CGRP or SNP will increase motion sickness susceptibility and motion-induced nausea in mouse models, and that migraine blockers can block these changes induced by systemically delivered CGRP or SNP., Methods: We investigated two measures of motion sickness assessment [motion sickness index (MSI) scoring and motion-induced thermoregulation] after intraperitoneal injections of either CGRP or SNP in C57BL/6J mice. The drugs olcegepant, sumatriptan and rizatriptan were used to assess the efficacy of migraine blockers., Results: MSI measures were confounded by CGRP's effect on gastric distress. However, analysis of tail vasodilatations as a surrogate for motion-induced nausea was robust for both migraine triggers. Only olcegepant treatment rescued tail vasodilatations., Conclusions: These preclinical findings support the use of small molecule CGRP receptor antagonists for the treatment of motion-induced nausea of migraine, and show that triptan therapeutics are ineffective against motion-induced nausea of migraine. Trial Registration: Not Applicable., Competing Interests: Declaration of conflicting interestsThe authors declare that there are no potential conflicts of interest with respect to the research, authorship and/or publication of this article.

Purpose: The purpose of this study was to investigate the influence of potential co-occurring symptoms, including fatigue, sleep disturbance, anxiety, depressive symptoms, and pain, on the incidence of postdischarge nausea (PDN) measured two days following discharge to home after surgery for breast cancer., Design: This study used a prospective, cross-sectional, observational design., Methods: The sample was 334 women aged 27 to 88 years of age. Demographic data were collected from the patient and the medical record before surgery. Symptom data were collected 48 hours following surgery using the Patient Reported Outcome Measurement System (PROMIS) and numerical nausea and pain scales., Findings: Eighty-five (25.4%) of study participants reported some nausea two days after discharge. Study participants who experienced PDN frequently described that it occurred after they left the hospital to drive home following their surgery. Unadjusted odds ratios showed the presence of co-occurring symptoms of anxiety, fatigue, sleep disturbance, and pain were all significantly associated with the presence of nausea 48 hours following surgery. Other significant factors associated with (PDN) were history of motion sickness, history of pregnancy-induced nausea, use of opioids, and type of surgery., Conclusions: Same-day surgery nurses providing postoperative education for women following surgery for breast cancer should explain to patients that nausea may occur after they are discharged, especially those with known motion sickness. In addition, patients should be informed that other symptoms, especially fatigue, sleep disturbance, and anxiety, may co-occur., (Copyright © 2022 American Society of PeriAnesthesia Nurses. Published by Elsevier Inc. All rights reserved.)

Objective: To investigate the clinical features of patients with definite vestibular migraine (dVM)., Methods: A total of 91 patients with vestibular symptoms accompanied by migraines/migraine-like symptoms were enrolled and diagnosed according to the criteria of the Bárány Society and the International Headache Society. Baseline data were collected. Videonystagmography and immune-related laboratory tests were performed., Results: Among the 91 patients, 62 (68.1%) had dVM (11 men, 51 women). Among dVM patients, migraine occurred earlier than vestibular symptoms in 42 (67.7%) patients. Spontaneous vertigo occurred in 41 (66.1%) patients. Induced vertigo occurred in 21 (33.9%) patients. Motion sickness occurred in 33 (53.2%) patients. Central oculomotor dysfunction was observed in 11 (17.7%) patients. Caloric test revealed unilateral horizontal semicircular canal dysfunction in 12 (19.4%) patients. Severe intolerance during the test occurred in 44 (71.0%) patients with dVM. 12 (19.4%) patients showed abnormal immune-related indicators., Conclusion: dVM is more common in women. The onset of migraine precedes that of vestibular symptoms, which are often accompanied by photophobia and phonophobia. Motion sickness and severe caloric test intolerance can contribute to the diagnosis of dVM. Immunological indicators are abnormal in some patients with dVM, dVM may be secondary or an accompanying disorder, but the causal relationship needs further investigation., Level of Evidence: IV., (Copyright © 2022. Published by Elsevier Editora Ltda.)

Objective: To evaluate demographic and clinical features of vestibular migraine (VM) patients METHODS: Four hundred fifteen patients with VM were evaluated by using a structured questionnaire in addition to clinical examination., Results: The mean age of headache and vertigo onset was 25 years and 39 years, respectively. In 12.3%, benign paroxysmal positional vertigo (BPPV) was detected during the interictal period. Ten percent had hearing loss on audiometry, in 8.7% it was one-sided low-frequency sensory-neural hearing loss below 2000 Hz and the history was typical for Meniere's disease (MD) in addition to VM. Tinnitus was present in 94.4%, aural fullness in 83.4%, nausea in 72.2% and vomiting in 30.5% of patients with VM/MD. The prevalence of these symptoms was higher in patients with VM/MD than in pure VM. Median attack severity determined by visual analog scale measured in centimeters from 0 to 10 was 8 for headache and 7 for vertigo for the whole group. Severe headache was significantly correlated with age of ≤ 43 years (OR: 6.831, 95% CI: [4.10-11.63]; p < 0.001) and severe vertigo was significantly correlated with age ≥ 41 years (OR: 7.073, 95% CI: [4.55-10.98]; p < 0.001). Motion sickness was revealed from past medical history in 51.8%. Family history of migraine was present in 72.5% and the age of onset of both migraine headaches (p = 0.008) and vertigo attacks (p = 0.004) was lower in these patients., Conclusion: Younger patients suffered more severe headache attacks whereas vertigo attack severity was higher in the elderly. BPPV and MD were commonly associated with VM and VM/MD was accompanied by aural and autonomic features more frequently than pure VM. Previous history of motion sickness was detected in more than half of the whole group. Family history of migraine was associated with younger onset of migraine headaches and vertigo attacks., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Background: Sopite syndrome is a poorly understood symptom complex characterized by drowsiness and lethargy relating to motion sickness. Though often occurring in conjunction with the classic symptomatology of motion sickness, the literature suggests that sopite syndrome is a separate entity that may occur independently of the feelings of nausea characteristic of traditional motion sickness. Additionally, the syndrome can last long after symptoms of nausea have subsided and can be debilitating to some patients. Due to the frequent concomitance of sopite syndrome and the classic symptoms of motion sickness, the syndrome may frequently go unidentified and there is a paucity of data recording its exact incidence in the available literature., Case Report: In this study, we report a case of sopite syndrome identified in a 23-yr-old student naval aviator who was ultimately unable to overcome his symptoms and adapt to the dynamic environment of flight., Discussion: This process is particularly relevant to student aviators and others involved in transportation settings where the existence of even mild performance challenges may create the potential for operational hazards. Because the training of aviators and flight officers is historically one of the most expensive investments undertaken by the Department of the Navy each year, documenting unique manifestations of this common problem and addressing them early in the training pipeline may help reduce the time and financial burden associated with student naval aviator attrition in the later stages of training.Gemender MS, Sholes PC, Haight SP. Sopite syndrome identified in a student naval aviator. Aerosp Med Hum Perform. 2018; 89(9):848-850.

Our objective was to assess the influence of visual flow direction on physiological changes and symptoms elicited by cybersickness. Twelve healthy subjects (6 male and 6 female) were exposed to a 15-min virtual ride on a rollercoaster on two different days in a counterbalanced manner, such half of participants were facing forward during the first ride while another half was facing backward. Forehead skin conductance, heart rate and HRV parameters (SDRR, RMSSD) were collected as objective measures; subjective symptoms were assessed with the Motion Sickness Assessment Questioner immediately after exposure. We found that while nausea ratings at which participants terminated the experiment did not differ between forward/backward rides, the mean ride tolerance time was significantly longer during reverse ride compared to forward ride (6.1±0.4 vs 5.0±0.5 min, respectively, p = 0.01, η2 = 0.45). Analysis of HRV parameters revealed significant reduction in both RMSSD (p = 0.02, t = 2.62, η2 = 0.43) and SDRR (p = 0.01, t = 2.90, η2 = 0.45) in the forward ride; no such changes were found in the backward ride. We also found that amplitude of phasic changes in forehead skin conductance increased significantly in both ride directions. This increase however was significantly lower (p<0.05) in backward ride when compared to the forward ride. When assessed immediately post-ride, subjects reported significantly lower (p = 0.04) subjective symptom intensity after the reverse ride compared to the forward ride. We conclude that the direction of visual flow has a significant effect on the symptoms reported by the subjects and on the physiological changes during cybersickness.

Hypothermic responses accompany motion sickness in humans and can be elicited by provocative motion in rats. We aimed to determine the potential role in these responses of the efferent cholinergic vestibular innervation. To this end, we used knockout (KO) mice lacking α9 cholinoreceptor subunit predominantly expressed in the vestibular hair cells and CBA strain as a wild-type (WT) control. In WT mice, circular horizontal motion (1Hz, 4cm radius, 20min) caused rapid and dramatic falls in core body temperature and surface head temperature associated with a transient rise in the tail temperature; these responses were substantially attenuated in KO mice; changes were (WT vs. KO): for the core body temperature-5.2±0.3 vs. -2.9±0.3°C; for the head skin temperature-3.3±0.2 vs. -1.7±0.2°C; for the tail skin temperature+3.9±1.1 vs+1.1±1.2°C. There was a close correlation in the time course of cooling the body and the surface of the head. KO mice also required 25% more time to complete a balance test. We conclude: i) that the integrity of cholinergic efferent vestibular system is essential for the full expression of motion-induced hypothermia in mice, and that the role of this system is likely facilitatory; ii) that the system is involvement in control of balance, but the involvement is not major; iii) that in mice, motion-induced body cooling is mediated via increased heat flow through vasodilated tail vasculature and (likely) via reduced thermogenesis. Our results support the idea that hypothermia is a biological correlate of a nausea-like state in animals., (Copyright © 2017 Elsevier Inc. All rights reserved.)

We present 2 anonymized cases to identify issues and challenges associated with long-haul in-flight medical emergencies. The first case involved a middle-aged man with a history of carditis on a systemic steroid who developed vomiting and rigor. Four physicians, including a pediatric intensivist, responded to the emergency call. In the second case, a pediatric trainee who was the only onboard medical personnel was summoned for help when a middle-aged man developed acute shortness of breath while traveling on a commercial flight. The cases illustrate the challenges and issues on the critical decisions of diagnosis, resuscitation, and whether the flight had to be returned or diverted. An extensive literature search is made to summarize the evidence available for these decisions and challenges. Epidemiology and outcomes associated with these medical emergencies are reviewed. In-flight medical emergencies are not rare. Physicians of all disciplines should be prepared to deal with these emergencies and make sensible decisions when equipment and resources are likely to be limited., (Copyright © 2017 Air Medical Journal Associates. Published by Elsevier Inc. All rights reserved.)

There are individual differences in the frequency of chemotherapy-induced nausea and vomiting (CINV) in cancer patients. We investigated the individual variability in susceptibility to CINV with focus on both behavioral factors and genetic factors in Japanese cancer patients. We performed a prospective study to investigate the association between patient attributes (backgrounds and habits as well as gene polymorphisms) and anorexia, nausea, or vomiting in 55 Japanese cancer patients undergoing chemotherapy at Nagoya University Hospital. We found that gender (female), use of non-steroidal anti-inflammatory drugs, susceptibility to motion sickness, and anxiety were associated with the frequency of CINV. Gene polymorphisms of rs1076560 (dopamine D 2 receptor gene), rs6766410 (serotonin 5-HT 3C receptor gene) and rs4680 (catechol-O-methyltransferase gene) were also associated. Our data suggest that these attributes may thus be risk factors for CINV. Our results provide novel information that can be used to predict the incidence of CINV in Japanese patients undergoing chemotherapy; this can help provide a substantial improvement in supportive care for patients with different types of cancer.

Objective: Evaluation and management of vertigo in children vary between institutions and medical specialties. The aim of this study is to describe the characteristics of vertigo in children presenting to a pediatric neurology referral center and to investigate the relationship between vertigo and migraine., Study Design: Patients <18 years old presenting with vertigo to Hacettepe University Ihsan Dogramaci Children's Hospital Neurology Unit between January 1996-January 2012 were included (n = 100). Data were obtained from patient files and phone interviews., Results: Mean age was 7.5 years. The most common etiological groups were benign paroxysmal vertigo of childhood (BPVC) (39%), psychogenic vertigo (21%), epileptic vertigo (15%), and migraine-associated vertigo (MAV) (11%). BPVC was the most common diagnosis in children ≤5 years of age while psychogenic vertigo prevailed in children >5 years. Staring episodes characterized epileptic vertigo patients (p = 0.021) while headache was more often described by MAV patients (p < 0.001). Vertigo attacks >5 min were uncommon in BPVC patients compared to others (p = 0.013). Twenty percent of BPVC patients contacted through phone interviews were experiencing migraine type headaches that started at a median age of 7.5 years. An algorithm for evaluation of children with vertigo was formed based on data obtained from this study and the literature. When this algorithm was applied to 100 cases of this series, 88 (88%) were correctly diagnosed., Conclusion: While most vertigo cases in children can be diagnosed accurately by a detailed medical history, physical and neurological examination, a standard algorithm can help with the correct classification., (Copyright © 2014 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.)

The skin conductance (SC) signal is one of the most important non-invasive indirect measures of autonomic outflow. Several mathematical models have been proposed in the literature to characterize specific SC features. In this work, we present a method for the estimation of central control of sudomotor nerve impulse (SMI) function using SC. The method is based on a differential formulation decomposed into two first order differential equations. We validate our estimation framework by applying it on an experimental protocol where eleven motion sickness-prone subjects were exposed to a nauseogenic visual stimulus while SC and fMRI signals were recorded. Our results show an expected significant increase in the mean amplitude of SMI peaks during the highest reported nausea, as well as a decreasing trend during recovery, which was not evident for skin conductance level. Importantly, SMI/fMRI analysis found a negative association between SMI and fMRI signal in orbitofrontal, dorsolateral prefrontal, and posterior insula cortices, consistent with previous studies correlating brain fMRI and microneurographic signals.

Objective: In this study, we investigated the effects of mild motion sickness and sopite syndrome on multitasking cognitive performance., Background: Despite knowledge on general motion sickness, little is known about the effect of motion sickness and sopite syndrome on multitasking cognitive performance. Specifically, there is a gap in existing knowledge in the gray area of mild motion sickness., Method: Fifty-one healthy individuals performed a multitasking battery. Three independent groups of participants were exposed to two experimental sessions. Two groups received motion only in the first or the second session, whereas the control group did not receive motion. Measurements of motion sickness, sopite syndrome, alertness, and performance were collected during the experiment, Results: Only during the second session, motion sickness and sopite syndrome had a significant negative association with cognitive performance. Significant performance differences between symptomatic and asymptomatic participants in the second session were identified in composite (9.43%), memory (31.7%), and arithmetic (14.7%) task scores. The results suggest that performance retention between sessions was not affected by mild motion sickness., Conclusion: Multitasking cognitive performance declined even when motion sickness and soporific symptoms were mild. The results also show an order effect. We postulate that the differential effect of session on the association between symptomatology and multitasking performance may be related to the attentional resources allocated to performing the multiple tasks. Results suggest an inverse relationship between motion sickness effects on performance and the cognitive effort focused on performing a task., Application: Even mild motion sickness has potential implications for multitasking operational performance.

In 1976, Graybiel and Knepton proposed the term "sopite syndrome" to describe a symptom complex centering on drowsiness and lethargy related to motion sickness. However, existing descriptions and definitions of sopite syndrome have limitations in fully conveying the appropriate information to the reader. Our objective is to propose a revised definition providing a more adequate conceptual framework for research. The proposed definition of sopite syndrome addresses the nonspecificity of soporific symptoms, the health state of the individuals, and the existence of a motion stimulus.

Nausea is a prominent symptom and major cause of complaint for patients receiving anticancer chemo- or radiation therapy. The arsenal of anti-nausea drugs is limited, and their efficacy is questionable. Currently, the development of new compounds with anti-nausea activity is hampered by the lack of physiological correlates of nausea. Physiological correlates are needed because common laboratory rodents lack the vomiting reflex. Furthermore, nausea does not always lead to vomiting. Here, we report the results of studies conducted in four research centers to investigate whether nausea is associated with any specific thermoregulatory symptoms. Two species were studied: the laboratory rat, which has no vomiting reflex, and the house musk shrew (Suncus murinus), which does have a vomiting reflex. In rats, motion sickness was induced by rotating them in their individual cages in the horizontal plane (0.75 Hz, 40 min) and confirmed by reduced food consumption at the onset of dark (active) phase. In 100% of rats tested at three centers, post-rotational sickness was associated with marked (~1.5°C) hypothermia, which was associated with a short-lasting tail-skin vasodilation (skin temperature increased by ~4°C). Pretreatment with ondansetron, a serotonin 5-HT3 receptor antagonist, which is used to treat nausea in patients in chemo- or radiation therapy, attenuated hypothermia by ~30%. In shrews, motion sickness was induced by a cyclical back-and-forth motion (4 cm, 1 Hz, 15 min) and confirmed by the presence of retching and vomiting. In this model, sickness was also accompanied by marked hypothermia (~2°C). Like in rats, the hypothermic response was preceded by transient tail-skin vasodilation. In conclusion, motion sickness is accompanied by hypothermia that involves both autonomic and thermoeffector mechanisms: tail-skin vasodilation and possibly reduction of the interscapular brown adipose tissue activity. These thermoregulatory symptoms may serve as physiological correlates of nausea.

Susceptibility to motion sickness is a predictor of postoperative nausea and vomiting, and studies in humans suggest that genetic factors determine sensitivity to motion sickness. The aim of the current study was to determine if a preclinical model could be selectively bred for motion-induced emesis and to assess a potential relationship to anesthesia-induced emesis. Musk shrews were tested for motion-induced emesis using a shaker plate (10min, 1Hz, and 4cm of lateral displacement). Animals were rank ordered for motion-induced emesis and selectively bred to produce high and low response strains. Shrews were also tested with nicotine (5mg/kg, sc), copper sulfate (CuSO4; 120mg/kg, ig), and isoflurane anesthesia (10min; 3%) to measure responses to a panel of emetic stimuli. High response strain shrews demonstrated significantly more emetic episodes to motion exposure compared to low response strain animals in the F1 and F2 generations. In F2 animals, there were no significant differences in total emetic responses or emetic latency between strains after nicotine injection or CuSO4 gavage. However, isoflurane exposure stimulated more emesis in F1 and F2 high versus low strain animals, which suggests a relationship between vestibular- and inhalational anesthesia-induced emesis. Overall, these results indicate genetic determinants of motion sickness in a preclinical model and a potential common mechanism for motion sickness and inhalational anesthesia-induced emesis. Future work may include genetic mapping of potential "emetic sensitivity genes" to develop novel therapies or diagnostics for patients with high risk of nausea and vomiting., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Metoclopramide is commonly used to treat vomiting caused by seasickness and acute gastroenteritis on cruise ships and serious adverse effects have not been reported from use at sea. We report severe long-lasting adverse effects in a young female seafarer following short-term, low-dose use of metoclopramide. During rough seas a 25-year-old female musician on a cruise vessel presented with nausea and vomiting. She was given intramuscular metoclopramide 10 mg and diphenhydramine 25 mg. Vomiting stopped after the injections, but she felt tired, confused and dizzy. She then had been taking metoclopramide 5-10 mg a day, but stopped after a total per oral dose of 30 mg as she developed disturbing symptoms that she related to the medication, including dizziness, anxiety, fatigue, depression and involuntary movements (twitches, jerks, ticks, and tremors of the eyelids, tongue, neck, fingers, arms and legs). Neurological examination, blood tests, electrocardiography and magnetic resonance imaging of the brain were all normal. Although gradually reduced in strength and frequency, the adverse effects were very disturbing for about 10 months, but at 13 months she was almost fully recovered. For many years numerous vomiting sea travellers have been successfully treated with a single parenteral 10 mg dose of metoclopramide. There are no obvious reasons why our previously healthy patient experienced such serious and long-lasting side effects after low-dose, short-term metoclopramide administration. Until more is known, metoclopramide should be reserved for debilitating cases - and only be given after other remedies have been tried and found ineffective.

Introduction: Previous research has shown that retinal slip can be a significant factor in causing motion sickness. Stroboscopic illumination may prevent retinal slip by providing snapshots of the visual environment that are brief enough so each image is stationary on the retina., Methods: The purpose of this study was to determine the effectiveness of an 8-Hz stroboscopic environment as a motion sickness countermeasure for passengers during a nauseogenic flight in a helicopter. The study population was comprised of 18 motion sickness susceptible subjects. Subjects completed a motion sickness symptom questionnaire, a psychomotor vigilance test, weapons utilization tasks, a time estimation task, and a sustained attention task after nauseogenic flights with and without 8-Hz stroboscopic illumination in the cabin., Results: Baseline-corrected scores of self-reported nausea were significantly lower after the stroboscopic condition (M = 36.57 +/- 6.95) than the nonstroboscopic condition (M = 50.88 +/- 7.36). Furthermore, the stroboscopic condition resulted in significantly better performance on the vigilance task than the nonstroboscopic condition. However, baseline-corrected scores of oculomotor symptoms were greater after the stroboscopic condition (M = 33.27 +/- 5.52) than the nonstroboscopic condition (M = 24.85 +/- 4.10)., Discussion: These results support the use of stroboscopic illumination as a nonpharmacologic countermeasure for motion sickness related to retinal slip. However, due to the uncontrolled nature of the flights, the possibility that these results could have been influenced by differences in motion between flights cannot be excluded. This technology should be investigated in other forms of transportation (i.e., ground vehicles).

Background: We assessed frequency of vestibular symptoms in Headache Clinic patients over 10 years., Methods: A descriptive study of 5111 consecutive patients with tension-type headache or migraine, analyzed for dizziness/ vertigo accompanying headache and for a lifetime history of motion-sickness, cyclic vomiting, recurrent abdominal pain or atopy. Migraine patients were re-grouped as those with vestibular symptoms (dizziness/vertigo or motion sickness) and those without and their data then re-analyzed., Results: There were 1880 migraine patients and 3231 tension-type headache patients. Significantly more migraine patients than tension-type headache patients experienced vestibular symptoms (p< 0.0001). The migraine with vestibular symptoms group was significantly younger (p< 0.05) had more aura, more phonophobia with migraine attacks (p< 0.0001). Menstruation and reported sleep problems impacted on headaches. While past history of cyclical vomiting, recurrent abdominal pain or atopy was about twice as common in migraine with aura and it was also more common in migraine with vestibular symptoms than migraine without vestibular symptoms., Conclusions: Vestibular symptoms are common in migraine patients. Migraine with vestibular symptoms might constitute a special group, one more likely to have had cyclic vomiting, recurrent abdominal pain or atopy.

Purpose of Review: A systematic approach to the history and examination allows the physician to diagnose the most common vestibular disorders of the brain or inner ear. However, some less common disorders require a specific familiarity so that they are not misdiagnosed as one of the more common disorders,treated inappropriately, or misattributed to a psychogenic etiology. This article describes four of the less common disorders that can present with a primary problem of dizziness and imbalance: (1) mal de débarquement syndrome, (2) bilateral vestibulopathy, (3) cerebellar ataxia, and (4) vestibular schwannomas (ie, acoustic neuromas)., Recent Findings: Associated clinical features of mal de débarquement syndrome have recently been investigated to clarify the spectrum of the syndrome. The combination of cerebellar ataxia, neuropathy, and vestibular areflexia (bilateral vestibulopathy) has been summated into a new syndrome. Further refinement of ocular motor features of cerebellar ataxia can narrow genetic testing requirements. Vestibular schwannomas remain an uncommon etiology for isolated dizziness; recent imaging studies have helped quantify the low yield of screening MRI protocols for the evaluation of undefined dizziness., Summary: A working knowledge of these less common disorders will help the physician make the diagnosis efficiently by gathering key elements of the history and fine-tuning diagnostic testing.

Mal de debarquement syndrome (MdDS) is a disorder of phantom perception of self-motion of unknown cause. The purpose of this work was to describe the quality of life (QOL) of patients with MdDS and to estimate the economic costs associated with this disorder. A modified version of a QOL survey used for another neurological disease (multiple sclerosis; MSQOL-54) was used to assess the impact of MdDS on QOL in 101 patients. The estimated economic costs were based on self-reported direct and indirect costs of individuals living in the United States using Medicare reimbursement payment rates for 2011 in 79 patients. Patients with MdDS reported a poor overall QOL as indicated by a mean composite QOL score of 59.26 ± 1.89 (out of 100). The subcategories having the lowest QOL rating were role limitations due to physical problems (18.32 ± 3.20), energy (34.24 ± 1.47), and emotional problems (36.30 ± 4.00). The overall physical health composite score including balance was 49.40 ± 1.69, and the overall mental health composite score was 52.40 ± 1.83. The cost to obtain a diagnosis was $2,997 ± 337, which included requiring an average of 19 physician visits per patient. The direct cost of MdDS medical care was $826 ± 140 per patient per year, which mainly included diagnostic imaging and physician visits. The indirect costs (i.e., lost wages) were $9,781 ± 2,347 per patient per year. Among 65 patients who were gainfully employed when they acquired MdDS, the indirect costs were $11,888 ± 2,786 per patient per year. Thus, the total annual cost of the disorder ranged from $11,493 ± 2,341 to $13,561 ± 2,778 per patient per year depending on employment status prior to developing MdDS. MdDS negatively and dramatically impacts QOL, and also imposes a substantial economic burden on MdDS patients. These findings underscore the need for further basic and clinical research on MdDS.

Objective: We wanted to study otolith function by measuring the static subjective visual vertical (SVV) in migraine patients and in controls with and without kinetosis (motion sickness)., Methods and Material: Forty-seven patients with moderately severe migraine and 96 healthy controls were enrolled. Using a questionnaire, persons with kinetosis were identified. The SVV test was performed in a totally dark room. Subjects wore a stiffneck to stabilize the head in an erect position. They were required to adjust an infrared line to the gravitational vertical with a hand-held infrared remote controlled potentiometer., Results: The deviation of SVV in the group of migraine patients was not significantly different from that of controls, regardless of whether an aura was associated. SVV was not significantly influenced by the presence of dizziness/non specific vertigo or kinetosis., Conclusion: Patients with moderately severe migraine under prophylactic medication correctly estimate the visual verticality in the headache-free period. It is suggested that a deviation of SVV in a headache-free migraine patient may not be attributed to his migraine disorder as such regardless whether kinetosis is associated., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Motion sickness is caused by exposure to unfamiliar motions and typical symptoms of motion sickness include nausea and vomiting. To observe the metabolic and hormonal differences between nausea/vomiting (NAV) subjects and non-nausea/vomiting (NNV) ones, and to understand how the differences in metabolites and hormones affect the tolerance of organism to acceleration, 60 volunteers were exposed to repetitive acceleration using a 6-degree-of-freedom ship motion simulator. Meanwhile, 36 rats were randomly divided into three groups: an acceleration model group (n=14, exposed to acceleration), insulin group (n=14, intraperitoneal injection of insulin 30 min before exposure to acceleration), and control group (n=8). Gas chromatography coupled to time-of-flight mass spectrometry (GC-TOF/MS) was applied to analyze the serum metabolites in human subjects. Serum glucocorticoid, insulin, and glucagon levels were determined by radioimmunoassay in the NAV and NNV subjects as well as in rats, and serum epinephrine level was determined by ELISA. After acceleration exposure, 9 metabolites, including L-histidine, L-ornithine, L-serine, L-tyrosine, pyroglutamic acid, fumaric acid, urea, n-dodecanoic acid and n-tetradecanoic acid, had different changes in the NAV and NNV groups. The serum levels of 4-hydroxy-L-proline, glucose, oleic acid and urea were significantly higher in the NAV group than in the NNV group after exposure; however, only the elevation degree of serum glucose was significantly greater in the NAV group than in the NNV group (P<0.05). Serum cortisol and epinephrine were increased in both groups. Before exposure, insulin level in the NAV group was significantly lower than that in the NNV group (P<0.05). After rotation exposure, rat serum glucose in the insulin group was significantly lower than that in the acceleration model group (P<0.001), and the motion sickness index was significantly lower than that in the acceleration model group (P<0.05). Our study provides the first evidence that stable glucose level can help to relieve gastrointestinal symptoms in motion sickness, and suggests that acute hyperglycemia is related to gastrointestinal symptoms in motion sickness., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Background: Motion sickness is characterized by subjective symptoms that include dizziness and nausea. Studies have shown that subjective symptoms of motion sickness are preceded by differences in standing body sway between those who experience the symptoms and those who are not. Boxers often report dizziness and nausea immediately after bouts. We predicted that pre-bout standing body sway would differ between boxers who experienced post-bout motion sickness and those who did not., Methodology/principal Findings: We collected data on standing body sway before bouts. During measurement of body sway participants performed two visual tasks. In addition, we varied stance width (the distance between the heels). Postural testing was conducted separately before and after participants' regular warm-up routines. After bouts, we collected self-reports of motion sickness incidence and symptoms. Results revealed that standing body sway was greater after warm-up than before warm-up, and that wider stance width was associated with reduced sway. Eight of 15 amateur boxers reported motion sickness after a bout. Two statistically significant interactions revealed that standing body sway before bouts differed between participants who reported post-bout motion sickness and those who did not., Conclusions/significance: The results suggest that susceptibility to motion sickness in boxers may be manifested in characteristic patterns of body sway. It may be possible to use pre-bout data on postural sway to predict susceptibility to post-bout motion sickness.

Question: Dimenhydrinate is an over-the-counter drug that is commonly used for the treatment of nausea and vomiting. Many of my adult patients use it, but is it safe and useful in the pediatric population?, Answer: Dimenhydrinate appears to be safe for use in the pediatric population. While little literature has been published about adverse effects of this medication, family physicians need to identify the cause of the vomiting before considering if the drug will be effective and need to ensure that patients safely use the medication and avoid potential interaction of the drug with other products.

Introduction: Airsickness affects many aviators, especially at the beginning of their flight training. From the symptoms of airsickness, stomach awareness and nausea are among the most common and unpleasant. Helicobacter pylori infection of the gastric mucosa is a common cause of gastrointestinal symptoms in the general population, although it has seldom been associated with motion sickness in the scientific literature., Methods: A retrospective review was conducted in all cases of pilot trainees taking basic flight training who were referred to the Hellenic Air Force Aeromedical Center due to airsickness and tested for H. pylori, for the time period 1996-2005. We compared the H.-pylori-positive pilots with the uninfected ones according to their responses to the habituation sorties and subsequent completion of the basic flight training as a whole. A statistical analysis was performed using Fisher's exact test., Results: The findings of the study suggest that diagnosing H. pylori infection and treating it with eradication therapy increases the possibility of a pilot trainee successfully completing the habituation flights, while it does not affect success in the basic flight training as a whole., Conclusions: Eradication therapy for H. pylori may provide a temporary reduction in reported nausea during flight training. The findings are not conclusive, but highly suggestive of a pathophysiologic link between H. pylori and motion sickness, needing further clarification through targeted studies., (Copyright © 2010 S. Karger AG, Basel.)

The brainstem is a structurally complex region, containing numerous ascending and descending fibres that converge on centres that regulate bodily functions essential to life. Afferent input from the cranial tissues and the special senses is processed, in part, in brainstem nuclei. In addition, brainstem centres modulate the flow of pain messages and other forms of sensory information to higher regions of the brain, and influence the general excitability of these cortical regions. Thus, disruptions in brainstem processing might evoke a complex range of unpleasant symptoms, vegetative changes and neurovascular disturbances and that, together, form attacks of migraine. Migraine is linked with various co-morbid conditions, the most prominent being motion sickness. Symptoms such as nausea, dizziness and headache are common to motion sickness and migraine; moreover, migraine sufferers have a heightened vulnerability to motion sickness. As both maladies involve reflexes that relay in the brainstem, symptoms may share the same neural circuitry. In consequence, subclinical interictal persistence of disturbances in these brainstem pathways could not only increase vulnerability to recurrent attacks of migraine but also increase susceptibility to motion sickness. Mechanisms that mediate symptoms of motion sickness and migraine are explored in this paper. The physiology of motion sickness and migraine is discussed, and neurotransmitters that may be involved in the manifestation of symptoms are reviewed. Recent findings have shed light on the relationship between migraine and motion sickness, and provide insights into the generation of migraine attacks., ((c) 2010. Published by Elsevier Ltd. All rights reserved.)

The mechanisms of vestibular migraine and motion sickness remain unknown. The aims of this study were to determine interictal vestibular dysfunction in migraineurs according to associated dizziness/vertigo and motion sickness, and to find out whether impaired uvulonodular inhibition over the vestibular system underlies the vestibular symptoms and signs by measuring tilt suppression of the vestibulo-ocular reflex (VOR). One hundred and thirty-one patients with migraine [65 with vestibular migraine (MV), 41 with migrainous dizziness (MD), and 25 with migraine only (MO)] and 50 normal controls underwent evaluation of vestibular function. Motion sickness was assessed using the motion sickness susceptibility questionnaire (MSSQ) and subjective scale. Compared with normal controls and MO group, patients with MV/MD showed increased VOR time constant (TC) and greater suppression of the post-rotatory nystagmus with forward head tilt. The mean MSSQ score and subjective scale were highest in MV group, followed by MD, MO, and controls (p = 0.002, p < 0.001). Multiple linear regression model analyses revealed that motion sickness is an independent factor of TC prolongation (p = 0.024). Twenty-eight (21.4%) patients with migraine also showed perverted head shaking nystagmus and 12 (9.2%) had positional nystagmus. In view of the increased tilt suppression of the VOR, we speculate that dysfunction of the nodulus/uvula may not account for the prolonged TCs in MD/MV. Instead, innate hypersensitivity of the vestibular system may be an underlying mechanism of motion sickness and increased TC in MD/MV. The increased tilt suppression may be an adaptive cerebellar mechanism to suppress the hyperactive vestibular system in migraineurs.

Background: A substantial number of individuals are at risk for the development of motion sickness induced nausea and vomiting (N&V) during road, air or sea travel. Motion sickness can be extremely stressful but the neurobiologic mechanisms leading to motion sickness are not clear. The endocannabinoid system (ECS) represents an important neuromodulator of stress and N&V. Inhibitory effects of the ECS on N&V are mediated by endocannabinoid-receptor activation., Methodology/principal Findings: We studied the activity of the ECS in human volunteers (n = 21) during parabolic flight maneuvers (PFs). During PFs, microgravity conditions (<10(-2) g) are generated for approximately 22 s which results in a profound kinetic stimulus. Blood endocannabinoids (anandamide and 2-arachidonoylglycerol, 2-AG) were measured from blood samples taken in-flight before start of the parabolic maneuvers, after 10, 20, and 30 parabolas, in-flight after termination of PFs and 24 h later. Volunteers who developed acute motion sickness (n = 7) showed significantly higher stress scores but lower endocannabinoid levels during PFs. After 20 parabolas, blood anandamide levels had dropped significantly in volunteers with motion sickness (from 0.39+/-0.40 to 0.22+/-0.25 ng/ml) but increased in participants without the condition (from 0.43+/-0.23 to 0.60+/-0.38 ng/ml) resulting in significantly higher anandamide levels in participants without motion sickness (p = 0.02). 2-AG levels in individuals with motion sickness were low and almost unchanged throughout the experiment but showed a robust increase in participants without motion sickness. Cannabinoid-receptor 1 (CB1) but not cannabinoid-receptor 2 (CB2) mRNA expression in leucocytes 4 h after the experiment was significantly lower in volunteers with motion sickness than in participants without N&V., Conclusions/significance: These findings demonstrate that stress and motion sickness in humans are associated with impaired endocannabinoid activity. Enhancing ECS signaling may represent an alternative therapeutic strategy for motion sickness in individuals who do not respond to currently available treatments.

The objective of this study was to evaluate, in patients with migraine and healthy volunteers, with and without a history of motion sickness, the degree of discomfort elicited by drifting striped patterns. Eighteen healthy volunteers (HV) and 30 migraine patients participated in the study. Discomfort was greater in migraine patients than in HV, and in individuals with a history of motion sickness than in those without, but the effect of history of migraine was independent of history of motion sickness. Generalized Estimating Equations models for binary correlated data revealed that these differences did not depend on levels of duty cycle, spatial and temporal frequencies. Visual discomfort in migraine patients was associated with worse performance. There was a significant correlation between median degree of discomfort across conditions and number of migraine attacks in the past month. Discomfort to drifting striped patterns may be related to central sensitization in migraine patients.

Nausea and emesis are common side effects of gastrointestinal disease. Reports indicate that ghrelin and endocannabinoids, agents that stimulate appetite, also reduce emesis evoked by chemotherapy treatment, which suggests that stimulation of feeding inhibits the emetic system. In the following study we conducted a more direct test of this hypothesis by determining the impact of manipulating the motivation to eat on emesis, using food restriction and refeeding. Emesis was induced in musk shrews, a commonly used animal model for emesis research, using the cancer chemotherapy agent cisplatin (20 mg/kg ip), nicotine (2 mg/kg sc), or motion (1 Hz, horizontal, 4-cm displacement), because these treatments are known to target separate emetic pathways: gut vagal afferents, area postrema, and vestibular pathways, respectively. Twenty-four hours of food restriction was sufficient to stimulate food intake, and 1 h of refeeding filled the stomach. The results indicate that food restriction, refeeding, and gastric fill had no significant effects on the amount of emesis produced by any of the emetic treatments tested here. This suggests that, although activation of the emetic system might have prominent effects on food intake, neural controls for feeding behavior do not significantly affect the neural pathways for emesis. These results may have implications for how we treat patients who experience a constellation of side effects, including nausea and emesis, since stimulating appetite may not necessarily inhibit emetic pathways.

Background: Limited evidence suggests that rizatriptan given before vestibular stimulation reduces motion sickness in persons with migraine-related dizziness. The present study was designed to test whether rizatriptan is also effective in protecting against visually-induced motion sickness and to test whether rizatriptan blocks the augmentation of motion sickness by head pain., Material and Methods: Using randomized double-blind, placebo-controlled methodology, 10 females, 6 with migrainous vertigo (V+) and four without vertigo (V-) received 10 mg rizatriptan or placebo two hours prior to being stimulated by optokinetic stripes. Visual stimulation was coupled with three pain conditions: no pain (N), thermally-induced hand pain (H) and temple pain (T). Motion sickness and subjective discomfort were measured., Results: Motion sickness was less after pre-treatment with rizatriptan for 4 of 10 subjects and more for 5 of 10 subjects. Augmentation of motion sickness by head pain was seen in 6 of 10 subjects; this effect was blunted by rizatriptan in 4 of these 6 subjects. Subjective discomfort was significantly more noticeable in V+ subjects as compared with V- subjects., Conclusions: These pilot data suggest that rizatriptan does not consistently reduce visually-induced motion sickness in migraineurs. Rizatriptan may diminish motion sickness potentiation by cranial pain.

Maropitant (Cerenia), a selective neurokinin(1) receptor antagonist, was evaluated for efficacy and safety in prevention of vomiting due to motion sickness in dogs in two randomized clinical trials. One-hundred eighty-nine dogs with a history of motion sickness were enrolled at 26 veterinary clinics (across 12 US states) across the two trials; of these, 163 were fully evaluable, 19 were evaluable only for safety, and seven were not evaluable. Each trial used a two-period crossover design. Each dog was treated orally with placebo or maropitant (minimum dose of 8 mg/kg body weight using unit dosing) tablets at approximately 2 h (Trial 1) or 10 h (Trial 2) before an automobile ride of approximately 60 min, during which dogs were observed for signs of motion sickness. Following a 10-14-day washout period, each dog was administered the opposite treatment and taken for another journey (same route, driver and vehicle). Maropitant reduced the occurrence of vomiting compared to placebo by 86.1% or 76.5% when given approximately 2 or 10 h prior to travel, respectively. No significant clinical signs were observed after maropitant treatment. Maropitant was safe and effective in preventing vomiting due to motion sickness in dogs when administered at a minimum dose of 8 mg/kg body weight as oral tablets 2 or 10 h prior to travel.

The effect of cannabinoids on motion-induced emesis is unknown. The present study investigated the action of phytocannabinoids against motion-induced emesis in Suncus murinus. Suncus murinus were injected intraperitoneally with either cannabidiol (CBD) (0.5, 1, 2, 5, 10, 20 and 40 mg/kg), Delta(9)-tetrahydrocannabinol (Delta(9)-THC; 0.5, 3, 5 and 10 mg/kg) or vehicle 45 min. before exposure to a 10-min. horizontal motion stimulus (amplitude 40 mm, frequency 1 Hz). In further investigations, the CB(1) receptor antagonist, N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM 251; 5 mg/kg), was injected 15 min. prior to an injection of Delta(9)-THC (3 mg/kg). The motion stimulus was applied 45 min. later. The number of emetic episodes and latency of onset to the first emetic episode were recorded. Pre-treatment with the above doses of CBD did not modify the emetic response to the motion stimulus as compared to the vehicle-treated controls. Application of the higher doses of Delta(9)-THC induced emesis in its own right, which was inhibited by AM 251. Furthermore, pre-treatment with Delta(9)-THC dose-dependently attenuated motion-induced emesis, an effect that was inhibited by AM 251. AM 251 neither induced an emetic response nor modified motion-induced emesis. The present study indicates that Delta(9)-THC, acting via the CB(1) receptors, is anti-emetic to motion, and that CBD has no effect on motion-induced emesis in Suncus murinus.

Objective: To investigate the clinical features and natural history of mal de debarquement (MdD)., Design: Retrospective case review with follow-up questionnaire and telephone interviews., Setting: University Neurotology Clinic., Patients: Patients seen between 1980 and 2006 who developed a persistent sensation of rocking or swaying for at least 3 days after exposure to passive motion., Main Outcome Measure: Clinical features,diagnostic testing, and questionnaire responses., Results: Of 64 patients(75% women) identified with MdD, 34 completed follow-up questionnaires and interviews in 2006. Most patients had normal neurological exams, ENGs and brain MRIs. The average age of the first MdD episode was 39+/-13 years. A total of 206 episodes were experienced by 64 patients. Of these, 104 episodes (51%) lasted>1 month; 18%, >1 year; 15%, >2 years; 12%, >4 years, and 11%, >5 years. Eighteen patients (28%) subsequently developed spontaneous episodes of MdD-like symptoms after the initial MdD episode.There was a much higher rate of migraine in patients who went onto develop spontaneous episodes(73%) than in those who did not(22%). Subsequent episodes were longer than earlier ones in most patients who had multiple episodes.Re-exposure to passive motion temporarily decreased symptoms in most patients (66%).Subjective intolerance to visual motion increased (10% to 66%)but self-motion sensitivity did not(37% to 50%) with onset of MdD., Conclusion: The majority of MdD episodes lasting longer than 3 days resolve in less than one year but the probability of resolution declines each year. Many patients experience multiple MdD episodes. Some patients develop spontaneous episodes after the initial motion-triggered episode with migraine being a risk factor.

Background: Guidelines for postoperative nausea and vomiting (PONV) prevention are implemented widely but their effectiveness may be limited by poor adherence. We hypothesized that the use of an electronic decision support (DS) system would significantly improve guideline adherence., Methods: Medical information of all patients undergoing elective surgery in our regional teaching hospital is routinely entered in an anesthesia information management system at the preoperative screening clinic. Our departmental PONV prevention guidelines identifies patients as "high-risk" and thus eligible for PONV prophylaxis based on the presence of at least three of the following risk factors: female gender, history of PONV or motion sickness, nonsmoker status, and anticipated use of postoperative opioids. Using automated reminders, we studied the effect of DS on guidelines adherence using an off-on-off design. In these three study periods, we queried for all consecutive patients visiting the preoperative screening clinic who were eligible for PONV prophylaxis and studied how often it was prescribed correctly., Results: Between November 2005 and June 2006, 1340, 2715, and 1035 patients were included in the control, DS and post-DS periods, respectively. As a result of mandatory data entry of risk factors, the percentage of high-risk PONV patients increased from 28% in the control period to 32% and 31% in the DS and post-DS periods, respectively. During the control period, 38% of all high-risk patients were prescribed PONV prophylaxis. This increased to 73% during the DS period and decreased to 37% in the post-DS period., Conclusion: Electronic DS increases guidelines adherence for the prescription of PONV prophylaxis in high-risk PONV patients.

Out-of-plane head movements performed during fast rotation produce non-compensatory nystagmus, sensations of illusory motion, and often motion sickness. Adaptation to this cross-coupled Coriolis stimulus has previously been demonstrated for head turns made in the yaw (transverse) plane of motion, during supine head-on-axis rotation. An open question, however, is if adaptation to head movements in one plane of motion transfers to head movements performed in a new, unpracticed plane of motion. Evidence of transfer would imply the brain builds up a generalized model of the vestibular sensory-motor system, instead of learning a variety of individual input/output relations separately. To investigate, over two days 9 subjects performed pitch head turns (sagittal plane) while rotating, before and after a series of yaw head turns while rotating. A Control Group of 10 subjects performed only the pitch movements. The vestibulo-ocular reflex (VOR) and sensations of illusory motion were recorded in the dark for all movements. Upon comparing the two groups we failed to find any evidence of transfer from the yaw plane to the pitch plane, suggesting that adaptation to cross-coupled stimuli is specific to the particular plane of head movement. The findings have applications for the use of centrifugation as a possible countermeasure for long duration spaceflight. Adapting astronauts to unconstrained head movements while rotating will likely require exposure to head movements in all planes and directions.

The present work was designed to establish a novel animal model for motion sickness (MS) in rodents and to evaluate the effects of a combination of scopolamine and modafinil on MS with this novel method. It was found that the rats and mice presented several symptoms induced by rotation such as, piloerection, tremble, urinal and fecal incontinence. As the rats and mice are lack of emesis response to rotation, we used a score based on abovementioned symptoms as an index for the severity of MS in rodents. MS index was determined in 260 mice with this novel method. It was found that the distribution of MS index was normal (W=0.99; P=0.23. P>0.05 considered values' normal distribution). The effects of scopolamine on MS were studied in mice and rats. It was found that scopolamine significantly decreased MS index at the dose of 0.3 mg/kg in mice and 1.0 mg/kg in rats. Finally, the effects of a combination of scopolamine and modafinil were observed with this novel method in rats. It was found that the efficacy of the combination (5.0+5.0 mg/kg) was greater than the single drugs (10 mg/kg). Even the smallest dose of the combination (0.5+0.5 mg/kg) had a similar effect to large dose of scopolamine or modafinile when they were used alone. In conclusion, this animal model is suitable for MS study in rats and mice and the combination of scopolamine and modafinil might be a new method to treat or prevent MS.

Standing participants were passively restrained and exposed to oscillating visual motion. Thirty-nine percent of participants reported motion sickness. Despite passive restraint, participants exhibited displacements of the center of pressure, and prior to the onset of motion sickness the evolution of these displacements differed between participants who later became sick and those who did not. Claustrophobia occurred during restraint, but only among participants who became motion sick. The results are consistent with the postural instability theory of motion sickness. We discuss the possible relation between claustrophobia symptoms, postural movements and motion sickness incidence.

Objectives: Cyclic vomiting syndrome (CVS) is characterized by recurrent, explosive bouts of vomiting punctuating periods of normal health. Its prevalence is unclear in the world, and is unknown in Turkey. This study was designed to investigate its prevalence in Turkish school children., Methods: The study was performed on 1263 children, aged 6 to 17 years old, who were selected by systematic sampling method before, for the celiac disease prevalence study. The population was asked the questions relating to CVS. Children whose answers fulfilled CVS criteria were invited for clinical interview and physical examination at the hospital., Results: Of 1263 children, 24 (1.9%) fulfilled the criteria of CVS. Of them, 33.3% were male, 66.6% were female; the age ranged from 7 to 14 years old (mean age 10.5). The mean onset age was 7+/-3.4 years (5 to 12 years). The duration of attack ranged from 3 to 10 days (median: 5 days). Prodromal symptoms were reported in 25% of children with CVS. The episodes were accompanied by pallor, anorexia, feeling unwell, headache, abdominal pain, and photophobia in 100%, 100%, 83.3%, 66.7%, 58.3%, and 16.6%, respectively. Precipitating factors were reported by 20.8% of the children. Six children (25%) had migraine. A positive family history for migraine was noted in 7 (29.2%). Seven children (29.2%) suffered from travel sickness., Conclusions: In this first CVS prevalence study in Turkey, we found that CVS is highly prevalent in school children. For this reason, we emphasize that clinicians should be aware of this syndrome and consider it in the differential diagnosis of recurrent vomiting.

Motion sickness (MS) has been found to increase body-core cooling during immersion in 28 degrees C water, an effect ascribed to attenuation of the cold-induced peripheral vasoconstriction (Mekjavic et al. in J Physiol 535(2):619-623, 2001). The present study tested the hypothesis that a more profound cold stimulus would override the MS effect on peripheral vasoconstriction and hence on the core cooling rate. Eleven healthy subjects underwent two separate head-out immersions in 15 degrees C water. In the control trial (CN), subjects were immersed after baseline measurements. In the MS-trial, subjects were rendered motion sick prior to immersion, by using a rotating chair in combination with a regimen of standardized head movements. During immersion in the MS-trial, subjects were exposed to an optokinetic stimulus (rotating drum). At 5-min intervals subjects rated their temperature perception, thermal comfort and MS discomfort. During immersion mean skin temperature, rectal temperature, the difference in temperature between the non-immersed right forearm and 3rd finger of the right hand (DeltaTff), oxygen uptake and heart rate were recorded. In the MS-trial, rectal temperature decreased substantially faster (33%, P < 0.01). Also, the DeltaTff response, an index of peripheral vasomotor tone, as well as the oxygen uptake, indicative of the shivering response, were significantly attenuated (P < 0.01 and P < 0.001, respectively) by MS. Thus, MS may predispose individuals to hypothermia by enhancing heat loss and attenuating heat production. This might have significant implications for survival in maritime accidents.

Background: Within- and between-subject variability of susceptibility for motion sickness is well established, but which factors determine susceptibility is less well known., Objective: We investigated whether and to what degree sex, race, and head movements contribute to the development of nausea and vomiting (N&V) during pseudorotation in a vection drum in healthy participants., Methods: Male and female, Chinese and white subjects were exposed to 5x1 minute of circular vection in a conventional rotation drum, with half of the participants performing nausea-enforcing head movements. The symptom ratings (SR) at baseline and after stimulation, the time to perception of illusory self-motion (vection), and the total rotation tolerance (RT) were noted and compared between groups using a 2x2x2 analysis of variance., Results: A total of 48 healthy young adults (24 Chinese, 24 white; 12 males, 12 females in each group) screened for susceptibility to develop motion sickness participated in this study. SR at baseline and after rotation were significantly lower in Chinese compared with white subjects (for baseline SR: F=20.04, P<0.001; for maximal SR: F=7.09, P=0.011). Vection was equal between both groups, with no effects of gender or head movements. Rotation tolerance was significantly shortened for Chinese compared with white participants (mean [SEM], 216.5 [15.4] sec vs 262.6 [11.3] sec, respectively; F=7.21, P=0.011), with independent influence of head movements (F=8.84, P=0.005) but not of gender., Conclusions: In this study, the strongest intrinsic factor that contributed to N&V during circular vection was racial origin, whereas sex played a minor role in the degree of N&V under the conditions studied. Head movement-induced vestibular stimulation was a further contributing factor.

Purpose: Postoperative nausea and vomiting (PONV) is the most common postoperative complication after surgery and general anesthesia. PONV occurs primarily within the first 24 hours and can lead to significant morbidity, delayed hospital discharge, increased hospital costs and perhaps most importantly, poor patient satisfaction. We sought, in this study, to determine the prevalence of PONV and to identify risk factors in patients who underwent orthognathic surgery., Patients and Methods: We conducted a retrospective cross-sectional analytic survey of 553 consecutive patients over 14 years of age, who underwent maxillary and/or mandibular osteotomies at Kaiser Permanente Hospital (Oakland, CA), between January 2003 and March 2004. Patient-, anesthesia- and surgery-related factors that were considered to have a possible effect on the prevalence of PONV events were evaluated., Results: A total of 514 patients met the inclusion criteria. Among these patients, 40.08% experienced PONV during the first 24 hours after surgery. The most important predictive factors associated with an increased risk of PONV were female gender, young patients (15 to 25 years old), nonsmoking status, presence of predisposing factors (ie, prior history of motion sickness and/or PONV, vertigo or migraine headaches), use of volatile general anesthetics, maxillary surgery, postoperative pain level (PACU) and the use of postoperative analgesic opioid drugs. We found a directly proportional relationship between the number of risk factors and the prevalence of PONV., Conclusion: We found PONV had a high prevalence among patients undergoing orthognathic surgery. Further studies are needed to develop effective protocols for preventing this common and unpleasant problem.