The Healthy Traveler : Minding Motion Sickness

It can ruin a car trip or an airplane flight.

It’s been known to spoil a Mad Tea Party ride at Disneyland.

It can turn the most relaxing, romantic cruise into the voyage from hell.

But since most who suffer from motion sickness don’t seek medical help, experts are hard-pressed to say exactly how many are afflicted. There’s still debate, in fact, about its cause.

Scientists do agree on a few points. Those who have had one bout of motion sickness are likely to get it again. And the best prevention techniques vary greatly from person to person.

A phenomenon called “sensory mismatch” is believed to be the culprit. “The brain gets different messages from three different sensory systems,” said Dr. Fred Linthicum, a researcher at the House Ear Institute, Los Angeles. The eyes send one message, the ears another and the musculo-skeletal system yet another.

Suppose a passenger is riding in the back seat of a car on winding roads. As he stares at the back of the seat, his eyes tell him he is not moving. “But his behind tells him he’s bouncing and his inner ears (responsible for maintaining balance) tell him he is going around curves,” Linthicum said. “The central nervous system can’t accept all these conflicting messages.”

In recent years, there has been another theory under investigation, he said. Overstimulation of the balance center in the brain may affect the nearby center that regulates vomiting. But that has yet to be proven, he said.

Whatever its cause, motion sickness is often accompanied by queasiness, fatigue, lightheadedness and sleepiness. Travelers may also yawn, hyperventilate, have cold sweats and vomit.

But what is surprising is that those who get car sick may not get air sick; nor will people prone to air sickness necessarily be prone to car sickness. And people who can’t handle amusement park rides, may not necessarily have a problem with cars or boats, according to the experts.

At Disneyland, for instance, park visitors occasionally show up at the first-aid station complaining of motion sickness, said park spokesman John McClintock. Most often, they’ve just disembarked from the spinning Mad Tea Party tea cups or Space Mountain ride, according to a first-aid station nurse. Visitors are encouraged to lie down until the queasiness passes and are informed that motion sickness remedies are sold in the park . . . just in case it occurs again.

Car sickness tends to be more common in children than adults, studies have found, and some experts say women are more prone than men to motion sickness. Others theorize that women are probably just more likely than men to report the symptoms.

Once travelers have been motion sick, they can be “on guard,” said Robert Stern, a Pennsylvania State University researcher. Anxiety and fear can worsen the condition. Poor ventilation can also increase the changes of an attack

Prevention is easier than treatment, experts concur. To avoid or minimize motion sickness, they offer a plethora of suggestions:

* “Eat a small, nonfatty meal (before traveling),” Stern suggested, reasoning that getting sick is more likely if passengers are hungry. Crackers and carbonated soda are often advised. “Eat something every two hours,” Stern advised.

* “Look out (the window) while traveling so all the senses get a sense of motion,” Stern said.

* Consider over-the-counter remedies such as Dramamine (dimenhydrinate) or Bonine (meclizine). Follow package directions and take the pills before travel.

* Acupressure could be helpful, said Fred Siciliano, a Ventura licensed acupuncturist. Locate the spot two finger widths above the wrist crease, palm side, he suggested. Apply moderate pressure with the thumb for three to five minutes before boarding and during flight or other motion. This can calm the stomach, he said.

* Band-Aid-like patches impregnated with the drug scopolamine (Transderm-Scop) and usually placed behind the ear are available by prescription. Possible side effects include blurred vision and dry mouth.

The Healthy Traveler appears the second and fourth week of every month.