Motion Sickness

Motion Sickness, a specific symptom complex caused by the rocking of ships on waves. The rocking of a vessel consists mainly of three types of movement: tilting along the transverse and longitudinal axes, and the rising and falling of the vessel. The first type of movement (rolling) by itself may be the cause of motion sickness; with it, both ends of the vessel alternately rise and fall, while in the middle of the vessel the rocking is felt less. Tilting along the longitudinal axis has less effect, as the excursions of the vessel's sides are insignificant. Motion sickness manifests most strongly with a combination of all these movements (pitching), which depends on both the change in position of the body in all directions and the unevenness of the movements, with the falling of the vessel being particularly unpleasant for the patient with motion sickness. Psychological factors are also of great importance for the occurrence of motion sickness, as indicated by its appearance in some individuals already when boarding a vessel or later at the mere memory of motion sickness, when seeing it manifest in other individuals. - Almost all persons subjected to rocking suffer from motion sickness to one degree or another. Motion sickness most often occurs in persons with an easily excitable autonomic nervous system (vagotonic individuals) and in those suffering from stomach diseases. According to available statistics, about 3% of people are immune to motion sickness, but among these 3%, attacks of it can be observed during strong storms. The deaf and children under two years of age do not suffer from motion sickness; children under 6-8 years of age and the elderly are slightly predisposed. Some animals (horses, dogs) also contract motion sickness; cats and birds do not suffer from it. Pathogenesis. Many theories have been proposed to explain the mechanism of occurrence of motion sickness. The origin of motion sickness was explained by anemia of the brain, concussion of the brain, shaking of internal organs, particularly the stomach, and irritation of the retina of the eye by continuously fluctuating images. However, the very multitude of theories indicates their obvious inadequacy. Thus, anemia of the brain in motion sickness is a symptom, not a cause of the disease. Furthermore, persons prone to motion sickness become equally ill with it with both open and closed eyes. Internal organs often experience shaking no less intense than during rocking, yet motion sickness does not occur. In recent times, the most attention has been paid to the disturbance of body balance as the main cause of motion sickness. The essence of motion sickness is thus reduced to the irritation of the vestibular apparatus as the organ controlling body balance during rocking [James, Reynolds, Ewald and others; more recently Vaganu (1912)]. This explains the immunity to motion sickness in children, in whom the excitability of the vestibular apparatus is weak, as well as in the deaf. The irritation of the vestibular apparatus is transmitted to the nucleus of the vagus nerve, and thus the vagosympathetic system, which has ramifications in all organs, is involved in the process. The role of the vagus nerve in the pathogenesis of motion sickness is confirmed by the action of atropine as a vagotropic agent, which significantly alleviates or stops attacks of motion sickness. Symptomatology. The onset of the disease usually manifests as dizziness that gradually intensifies. Subsequently, nausea joins in, increasing from unpleasant odors, from the sight and smell of food, from the manifestation of motion sickness in other persons, etc.; vomiting occurs, after which the patient often experiences some temporary relief. With repeated attacks, the vomit takes on a mucous character, often with an admixture of small or large amounts of bile, and sometimes blood. The patient's face becomes pale, and severe weakness sets in: patients sometimes can barely stand on their feet and cannot get up from the bed. The pulse is slowed, soft, and small. Motion sickness is usually accompanied by constipation. According to some authors, the secretion of gastric juice is decreased, according to others, it is increased. The amount of urine is decreased. Headaches often join in. The mental state of patients with motion sickness is depressed; apathy and fear of new attacks of vomiting appear; sadness and despair are sometimes so strong that patients think of suicide. Sleep is disturbed; despite strong drowsiness, patients do not fall asleep, but doze or are in a state of semi-oblivion. - Course. In some cases, the disease is limited to dizziness and nausea, in others all the above-mentioned symptoms develop. But as a rule, all manifestations of motion sickness disappear immediately with the cessation of rocking, in some cases leaving behind only slight dizziness and general weakness, which also pass within a few hours. Usually, during long sea voyages, habituation to rocking occurs, and attacks of motion sickness weaken or do not appear at all, although there are people who never get used to rocking. - Motion sickness does not cause any complications in healthy people. It is believed that strong straining during vomiting can lead to the formation or complications of a hernia, cause bleeding, for example in tuberculosis of the lungs or a stomach ulcer, or cerebral hemorrhage in arteriosclerotics. It is doubtful whether motion sickness can be the cause of death. Prevention. Recumbent position, preferably in the fresh air rather than in a cabin; as close to the middle of the vessel as possible and far from kitchens and engine rooms. Diverting attention with some activity reduces the possibility of contracting motion sickness. Some recommend a moderate breakfast shortly before departure. In case of ptosis of abdominal organs, abdominal bandaging is useful. Among medicinal substances - bromides; veronal or medinal (0.5 one to two times a day); atropine subcutaneously - 1 cm³ (1:1,000). - Treatment. Everything said about the prevention of motion sickness also applies to its treatment. In addition, after attacks of vomiting, swallowing pieces of ice or drinking small amounts of cold liquid is recommended. Taking dry and cold food in small portions. For constipation - laxatives. Many medicinal substances have been proposed for the treatment of motion sickness, but most of them have no noticeable effect on its course. Most authors recommend bromides and veronal or medinal [0.5 one to two times a day on short journeys and 0.3 (2-3 times a day) for prolonged use]. Atropine - 1 cm³ (1:1,000) subcutaneously. For intractable vomiting - morphine subcutaneously. During airplane flights, typical attacks similar to motion sickness are observed, especially during descent, although to a lesser degree. Symptoms of motion sickness also appear during rapid descent in elevators and riding in railway trains ('car sickness', 'Eisenbahnkrankheit'), but in the latter cases it does not fully develop, and the matter usually remains limited to only slight dizziness, nausea, and malaise.