MOTION SICKNESS (DIZZINESS): SYMPTOMS, CAUSES AND TREATMENTS - NEUROPSYCHOLOGY - 2024

The motion sickness is a feeling of discomfort caused by movement, especially when traveling. The main symptoms that appear are nausea, vomiting, paleness, sweating, excessive salivation, drowsiness, lethargy and persistent fatigue.

The term motion sickness was introduced by Rosembach, to refer to the symptoms that appear due to intense or novel accelerations to which a person is not adapted. Therefore, its origin would be in sudden and external movements, as caused by a car accelerating and braking, a boat or an airplane.

It is likely that by reading all these symptoms you feel identified and it is a very common disorder, especially in children. It has been shown that almost all healthy people, when exposed to a moving stimulus, can develop kinetic dizziness.

Motion sickness or kinetic dizziness is a normal physiological response to unusual perception of movement. In other words, there is a conflict between visual perception and the perception of the inner ear, essential in controlling balance.

Causes of motion sickness

Our brain constantly integrates information both from where we are, and from our movement. The eyes and the vestibular system are in charge of constantly updating this information.

On the one hand, the eyes provide a visual image of our environment, while the vestibular system, located in the inner ear, is a network of nerves, channels and fluids, which is responsible for providing us with a sensation of balance or movement.

When we travel in a car, our visual system informs our brain that we are moving quickly, since objects outside are moving at high speed, however, our muscles and vestibular system inform otherwise, since that we are really sitting, not moving.

Due to the lack of coincidence between the information provided by both systems, the updating of the information about our state and position will be deficient, and therefore may lead to symptoms such as nausea and vomiting.

Currently, the theory of sensory conflict has been proposed and it is therefore accepted that kinesosis will develop when there are imbalances in the integration patterns of sensory information by virtue of real movements.

In what places can motion sickness appear?

This syndrome can be experienced in different places, depending on the triggering means of transport: boat, plane, car, train) and its appearance can even be associated with virtual reality technology.

However, dizziness and nausea can also occur while at an attraction, watching a movie, or playing games at a fast pace.

In addition, different visual stimuli such as the moving horizon line or some olfactory ones (poor ventilation or excess carbon monoxide), can also cause many of the symptoms of this syndrome.

Symptoms

The initial symptoms of this clinical syndrome of travel sickness usually include (HDS, 2016):

• Pallor.
• Cold sweat.
• Dizziness.
• Increased salivation
• Nausea vomiting

In addition, some people may also experience additional other symptoms (HDS, 2016):

• Shallow and rapid breathing.
• Headache.
• Tiredness and drowsiness

When the sensations begin, sweating may appear in as little as 5 seconds after the start of movement and is usually clearly visible before the nausea sensations appear. Progressively there will be an increase in salivation with repeated swallowing movements.

In addition, it is possible that rapid breathing or hyperventilation occurs that will induce changes in the distribution of blood volume, predisposing the subject to a situation of hypotension.

Nausea and vomiting may appear in an interval from minutes to hours after stimulation has started or after it stops.

This basic symptomatology can appear both in trips by sea, cars, trains, even space flights, it can reach such a high degree of intensity that many people refer phrases such as: "I have never had such a bad time", "I was about to jump through la borda ”, etc.

In general, the symptoms of this syndrome will begin to remit spontaneously from moments to hours after the cessation of stimulation. However, if the stimulus continues, as our body adapts to the environmental conditions and the repetition of the stimulus, the symptoms usually disappear in about three days.

Symptoms can also occur on land, especially after a boat trip. The "disembarkation disease" or "seasickness", is an impression of movement, people describe it as a sway or a sensation of inclination and wobbling.

It is normal for transient symptoms to appear after disembarkation that tend to disappear in the first 6 hours or in the following days.

Who can get travel sickness?

Anyone can get kinetic dizziness when traveling. However, its occurrence will depend on both individual susceptibility factors and the stimulating conditions to which we are exposed.

Sex and age have been shown to be predictors of this syndrome. Different statistical studies have shown that women are more susceptible than men to this type of motion sickness in transportation. In addition, the menstrual cycle and pregnancy can accentuate this susceptibility.

People who suffer from migraines may also be more prone to experiencing motion sickness and especially during a crisis. On the other hand, in relation to age, it is rare for kinetic dizziness to appear in children under two years of age.

Some authors consider that this is due to the absence of visuo-vestibular conflict, since the visual system does not begin to be fully used for visual orientation until they learn to stand and walk alone.

Generally, the tendency to dizziness grows from the first years, it is common among children from 3 to 12 years old, reaching a maximum peak around 10-12 years of age and later decreases to 20 years.

The natural tendency is expected to be a progressive decline with age, however, susceptibility is still present in many adult individuals.

Other factors that can contribute to the suffering of this type of dizziness have also been identified: genetic predisposition, aerobic exercise, psychological influence, history and exposure to experiences.

How can we avoid travel sickness?

When the sensations begin to appear, it is difficult to stop their occurrence. Due to this, the essential thing is to prevent its appearance:

• Avoid eating food if we are going to make a short trip and / or eat a light and light meal when the trip is going to be prolonged in time.
• It is recommended that we avoid carrying out activities that involve fixing our eyes on an object inside our means of transport: such as reading a book, reading a mobile phone, using a laptop, etc.
• Ventilation, the absence of strong odors or tobacco smoke will allow strong inspirations that can relieve the symptoms of nausea.
• Keep your head fixed and your gaze on a distant point outside.
• Avoid violent changes in speed, braking or taking sharp curves.

On the other hand, there are also specific positions that can prevent the appearance of symptoms:

• Drive the vehicle
• Sit in the front seats of a car or bus.
• Sit in the wing locations on an airplane.

In addition, other actions are also recommended:

• Reduction of sensory input by closing the eyes.
• Maintain hydration: consumption of water in small doses on a frequent basis.
• Limit the consumption of food and alcoholic or caffeinated beverages.
• Using distracting methods such as music or flavored candy.

Treatments

In cases in which the symptoms of motion sickness appear with a high intensity, recurrently or we carry out a profession that gives us a high risk of suffering from motion sickness on a frequent basis, it is advisable to use some pharmacological therapeutic measures and / or not -pharmacological.

Non-drug treatments

In the case of non-pharmacological interventions, delayed adaptation measures are used through habituation to the stimuli that trigger dizziness.

These interventions are based on the idea that a stimulus that is established gradually will generate fewer symptoms and therefore adaptation will be faster than if it appears suddenly.

Specifically, habituation techniques are used especially in the military or pilots or captains, since the medication is contraindicated due to the possible side effects of numbness or blurred vision (Sánchez-Blanco et al., 2014).

Although there is a decrease in symptoms, the stimulating adaptation mechanism is very specific, that is, if a person gets used to traveling in large boats, it is very possible that they may suffer sensations of motion sickness again in small boats.

Drug treatments

Pharmacological measures are the most used in the treatment of motion sickness. Antiemetic drugs are often used to prevent or reduce symptoms, however, they tend to cause drowsiness (Colegial Pharmaceutical Organization, 2016).

Other drugs that have been used for motion sickness are scopolamine, atidopaminergic drugs or benzodiazepines.

Although in many cases the drugs are effective, they are not applicable to all populations. Some drugs are contraindicated in children and pregnant women.

References

1. CDC. (2016). Motion Sickness. Obtained from the Centers for Disease Control and Prevention.
2. NHS. (2016). Motion Sickness. Obtained from NHS Choices.
3. Collegiate pharmaceutical organization. (2016). Kinetic motion sickness, motion sickness or motion sickness. Obtained from Portalfarma.com-
4. Sánchez-Blanco, C., Yañez González, R., Benito Orejas, J., Gordon, C., & Bautecas-Caletrio, A. (2014). Motion sickness Rev. Soc. Otorhinolaryngol., 5 (28), 233-251.
5. Zhang, L., Wang, J., Qui, R., Pan, L., Li, M., & Cai, Y. (2016). Motion sickness: current knowledge and recent advance. CNS Neuroscience & Therapeutics, 22, 15-24.