When I was a teenager, a friend of mine said: “Joe, would you like to go fishing some weekend? “Sure, but I don’t know anything about fishing.”
“Don’t worry. I’ll take care of everything.”
It was balmy Saturday morning when I got into an eighteen foot boat with a few fishing poles, bait, and two brown lunch bags that we brought along. There were no inflatable life jackets, but I did notice our GPS system, a compass at the bow, opposite the outboard motor.
The weather was ideal. Cumulus clouds drifted overhead and the Atlantic sea green ocean was calm; but as we motored along, the boat tumbled up and down as if you were riding a horse in an amusement park’s carousel. After a few hours in the boat, I began to feel queasy, clammy, nauseated and a bit dizzy. I thought if I ate part of my lunch I’d feel better. Mistake. Shortly thereafter, my lunch tumbled out. That was the first of several subsequent experiences I encountered with motion sickness.
Motion Sickness
“Sailing on the sea proves that motion disorders the body” — so wrote Hippocrates about 2600 years ago. Motion sickness, also called seasickness, carsickness or airsickness is a common problem. Approximately. three out of ten Americans are considered overly sensitive to motion sickness.
Nausea is the main symptom of motion sickness. Motion sickness is more common in children after the age of 2 years and in women. However, almost everyone is susceptible to motion sickness if one experiences intense motion.
Causes
Motion sickness occurs when the motion sensing parts of the body (eyes, inner ears, muscles, and joints) send conflicting signals to the brain. The contradictory signals confuse the brain so that it can’t decide if you’re stationary or moving. The incongruous messages relayed to the brain trigger different parts of the nervous system causing you to feel sick.
If you’re sitting on a seat in a train, or the back seat of a car looking out the window, your eyes may see passing houses, and apartment buildings. On the one hand, the eyes and inner ears message the brain that movement is happening. The ear signals (from the semicircular canals) go to the cerebellum, which is responsible for balance and movement. The signals also go to certain areas of the brainstem that can cause nausea and vomiting.
On the other hand, your body (muscle and joints), sends signals to the brain telling it that no movement is happening because you’re sitting motionless. The brain becomes confused with these conflicting, “toxic” messages making you feel sick.
If you’re booked on an ocean liner and encounter choppy seas, you might feel as if you’re sailing in an eighteen feet boat You look out at the horizon and it’s motionless, but your body is bouncing up and down. Once again, the brain is receiving conflicting signals.
Risk Factors such as inner ear problems make people more susceptible to motion sickness There’s a greater incidence of this disorder in children between the ages of 2-12 years, in people who suffer from migraine headaches, Parkinson’s disease and it’s more likely with the use of certain medications; and in women who are pregnant, menstruating or taking birth control pills. Adults greater than 50 years of age are less likely to experience motion sickness.
Symptoms
In some individuals, the slightest mismatch of sensory signals from the body to the brain can provoke significant symptoms, while the opposite is the case in other individuals. The predominant symptoms of motion sickness are nausea and vomiting. Other symptoms include anxiety, queasiness, cold sweats, pale skin, increased salivation, dizziness and headache. The diagnosis is made by asking you about your medical complaints, what brought on the symptoms and physical examination, particularly the ears and eyes.
Treatment
A) Drug Treatment
Antihistamines that cause drowsiness work to prevent motion sickness and can relieve the symptoms of this disorder. Histamines that do not cause drowsiness won’t ease your symptoms of motion sickness.
Scopolamine skin patches (Transderm Scop®) works to prevent nausea, and vomiting. It calms down your stomach, blocks signals in the part of your brain that causes nausea, and vomiting
You place the Transderm Scop patch behind the ear at least four hours before traveling. After three days, replace the patch with a new one. The patch is approved only for adults, and it can cause a dry mouth.
B) Behavioral Treatment
- Don’t read in a moving vehicle
- Sit in the front passenger seat or drive the vehicle
- Sit facing forward, e. g. on a train
- Minimize head movement
- Concentrate on a stable horizon
- Listen to pleasant music. If you are a passenger in a car, you might try using earphones to listen to music
- Use mindful breathing
- Some people find closing their eyes is helpful
- People claim placing an earplug in the ear lessens motion sickness.
Habituation can desensitize a person to motion sickness and has been used as an effective management tool. More data is needed for alternative treatments, which include acupressure on the anterior wrist and the use of ginger to counteract vomiting.
Motion sickness is a common problem that happens when the brain can’t make sense of the conflicting signals sent to it by the eyes, inner ears, muscles and joints. The contradictory signals can cause nausea, vomiting, dizziness and other symptoms. The symptoms of this disorder usually resolve within four to six hours after the stopping the motion (e. g., getting off the boat and onto land). If you’re prone to motion sickness, there are treatments to prevent and treat this disorder.
References
- CDC; Motion Sickness; Traveler’s Health, January 28,2022
- JF Golding, Motion Sickness; Handbook Clin Neuro 2006
- Veronica Takov; Prasanna Tadi; StatPearls, July 4, 2022.
- Koch, A.; et al; The Neurophysiology and Treatment of Motion Sickness; Dtsch Arztebl Int 2018
Glossary
- Nausea is derived from naus, the Greek word for ship (e. g., nautical).
This article is intended solely as a learning experience. Please consult your physician for diagnostic and treatment options.