Motion sickness seems to be caused by a mismatch between certain body receptors: the eyes, the vestibular mechanism in the ear, and position receptors to muscles and joints.
By: Lauren La Rose The Canadian Press, Published on Mon Apr 21 2014
Rocked by the choppiness of rough waters and feeling nauseous from food, Nadia Ali was ready to abandon ship.
“I was the most miserable person on that boat,” she recalled. “I wanted to jump off.”
A dinner catamaran cruise in Hawaii proved turbulent for the motion-sensitive Ali. And a six-hour ferry ride from Athens to the Greek island of Mykonos left her feeling similarly queasy.
“It was so rough ... It was not fun,” recalled Ali, 26. “I popped a Gravol that time, but I know it didn’t work because I was sick the entire time.
“I tried to go out to get some fresh air and just rest my head on the railing a little bit, but that wasn’t too safe, so they brought me back inside, and I just had to deal.
“I just kept my head (tilted) to the right.”
Travel health expert Dr. Jay Keystone said motion sickness seems to be caused by a mismatch between certain body receptors: the eyes, the vestibular mechanism in the ear, and position receptors to muscles and joints.
Keystone said the sensory conflict explains why some people experience difficulty sitting backward in moving vehicles.
“Your receptors are telling you you’re moving forward; your eyes are telling you you’re moving backwards. Remember, all of this is about a mismatch,” said Keystone, the medical director of the Medisys Travel and Adult Immunization Clinic in Toronto.
Those who experience difficulty with reading while in motion are also experiencing sensory conflict.
Keystone said motion sickness is often more pronounced in younger children up to 10 to 15 years of age and then improves.
“It may go away in some people — it’s certainly much better now with me — and I’m a senior. And I have much less problems that I had when I was younger,” said Keystone, also staff physician in the tropical disease unit at Toronto General Hospital, whose identical twin brother suffers from motion sickness as well.
“It may be the sensitivity of the system,” he added. “Remember, it’s the visual receptors. It’s the balance, the vestibular apparatus within the ear that just may be more sensitive in young children and as we get older we either acclimatize to it or accommodate to it, or the system changes.”
Keystone said the reason boats and amusement park rides are likely to exacerbate motion sickness is because there’s no uniform change in the environment.
“Your inner ear is thrown off because it’s constantly changing. And therefore, you’re getting a poor match with your visual and your inner ear.”
Jennifer Hicks, 41, can remember flying to visit family in British Columbia while growing up in Toronto and her and her twin sister suffering from motion sickness.
“It was like: ‘Who’s going to throw up first?’” she recalled with a laugh. “My poor mum.”
Hicks said if she’s feeling nauseous, she finds closing her eyes and focusing on breathing helps.
Hicks is also a longtime practitioner and instructor of Nia, a body-mind-spirit program that blends movement forms and Eastern and Western traditions from martial arts, dance arts and healing arts, like yoga. She believes her involvement in Nia has helped.
“I have a twin sister who doesn’t do Nia and she still experiences extreme motion sickness and I don’t,” said Hicks, 41.
“I think it’s that we do a lot of turning, so we’re actually training our vestibular system, our sense of balance and our sense of where I am in space. I can’t really explain it, but I feel like I’ve sort of fine-tuned.”
Keystone said he wouldn’t be surprised if that was the case.
“If you’re improving your co-ordination, then your co-ordination is also including your joints, your muscles and your inner ear.”
Keystone said there are a variety of measures individuals can take to help ease potential motion sickness symptoms. For starters, avoid consuming excessive amounts of alcohol and food.
“That increases pressure on the stomach and the abdomen and that may make you feel full. And then, if you get a change in your movement that actually makes it worse.”
Keystone said sitting up front is better than riding in the back seat where individuals are more likely to experience sensory conflict. In general, he recommends selecting a seat in a vehicle where there will be the least motion.
“If you’re in a car you want to be in the middle where there’s the least amount of rock and roll because you know that a vehicle rolls from side to side a little bit.”
The same philosophy applies to travel by water.
“If you can be in the middle — middle seat — certainly the lowest level on a ship because if a ship rocks to one side, the top of the ship moves much further than the bottom.”
For those opting for antinausea medication like Gravol, Keystone said individuals should take the dose an hour before departure. “If you wait until you’re already travelling, it’s going to be too late.”
Keyston said scopolamine — available as a tiny, transdermal patch placed behind the ear — is also effective. It can be administered anywhere from eight to 12 hours prior to travel and lasts for 72 hours — but isn’t for everyone.
“There’s certain things about scopolamine — especially in the elderly — that you need to think about. And it may cause a bit of blurred vision and the last thing you want is an older person to be walking along to trip and break something.”
Scopolamine also can’t be taken during pregnancy, he added.
Some people may opt for acupressure bands such as Sea-Bands. They are worn on each wrist and apply continuous pressure on acupressure points to help ease symptoms of nausea, upset stomach and motion sickness.
Keystone said studies on Sea-Bands are “kind of equivocal” — meaning they’re not one way or the other.
“People swear by them. And from my point of view, if it works for you, use it.”
Source: The Toronto Star