Motion Sickness--It’s Not in Mind, It’s in Ear

Millions of Americans are familiar with the symptoms, ranging from dizziness to nausea, of that specter of the vacation season, motion sickness.

Virtually anyone can succumb to car-, air- or seasickness, says the federal Food and Drug Administration, although the malady seems most common between the ages of 2 and 12.

Infants rarely suffer from the illness, and susceptibility declines with age, becoming rare over 50, the agency reports.

But anyone with a normal sense of balance, even animals, can suffer. Even codfish placed in a tank on the deck of a ship in rough water became ill, researchers report.

In the ocean, of course, codfish would simply dive into calmer water. That’s an option not available to youngsters bouncing in the back seat, or folks leaning over the rail of a ship or strapped into an airline seat.

While doctors say they do not completely understand all the interactions involved in motion sickness, it appears to originate with the inner ear, where liquid-filled tubes help the body maintain balance. When movement registered in these tubes conflicts with the signals received by the eyes, illness seems to follow.

For example, in one of the most common situations, someone is reading in a car. The ear registers motion, but the eye is fixed on a page. The signals received by the brain disagree: bingo, carsickness.

Generally, the FDA reports, the first symptoms include paleness of the skin followed by yawning, restlessness and a cold sweat. Drowsiness or sluggishness may follow.

This is the point when the victim usually begins to realize that something is awry, and what is likely to follow--excessive salivation, nausea and vomiting.

Symptoms progress rapidly in some people--as many parents know--while for others the development is slower.

Though very unpleasant, motion sickness rarely causes severe complications, although it can lead to bad headaches, exhaustion, dehydration and a mineral imbalance in the body.

Travelers can take some precautions to avoid this illness, FDA says:

- Try to place yourself where there is the least motion. In a car, sit in the front seat looking straight ahead. On airplanes, choose a seat over the wing. On boats, stay in the middle, on deck rather than below.

- If possible, lie in a semi-reclined position and keep your head as still as possible.

- Look ahead at the horizon or close the eyes, rather than looking at passing scenery or at waves. Placing children in an elevated seat in the front helps them by allowing them to look out the windshield.

- Focus attention on something other than motion. Although reading is not recommended, occupying children with toys or coloring, for example, may be better than having them stare out side windows.

In addition there are some drugs approved for use to prevent motion sickness, but they must be taken a half-hour or so before traveling. Among those on sale are cyclamine hydrochloride (Marezine), meclizine hydrochloride (Bonine) and dimenhydrinate (Dramamine).