Military Officer - April 2007 - (Page 46) askthedoctor Motion Sickness For many people, nausea is an unwelcome traveling companion. Rear Adm. Joyce Johnson, D.O., describes behavioral and medical approaches to ward off its ill effects. T Travel Sickness Can Affect Anyone ■ In the roughest seas, even the most experienced sailors can experience motion sickness. Astronauts also are affected; the space shuttles’ zero-gravity toilets have a special “vomit” setting. he body has several mechanisms to sense motion and position, which normally work together. The eyes send visual clues to the brain (often relating to a reference point, such as the horizon) to determine motion. In the inner ear, semicircular canals detect rotation, and the otolith organs recognize vertical movement. Through proprioception, the skin, joints, and other tissues recognize miniscule changes in pressure, such as the increased pressure on muscles to keep balance when a ship is rocking back and forth. Ideally, each of these sensors sends the same signal to the brain. When they send different messages, motion sickness results. Seasickness, car sickness, and illness from an airplane or train ride are all the same phenomenon. For example, a common cause of motion sickness is reading a book in a car: Sickness results because while the ears and proprioceptors detect motion, the eyes focusing on the book do not. Similarly, going below deck on a boat — where there are no visual cues about motion, but the inner ear and proprioceptors continue to sense it — can make someone sick. But the same person might feel fine on deck, where the body’s cues are consistent; the eyes, ears, and proprioceptors sense the same motion. Motion sickness includes fairly predictable symptoms. The first is slight nausea. This may be accompanied by a cold sweat, flushing, a drop in blood pressure, and general fatigue. Vomiting is usually the last step and typically does not relieve the symptoms (unlike most other instances of vomiting). Simple behavioral measures can ensure all signals going to the brain are sending the same message about the body’s motion and position. In a car, sitting in the front seat to see the horizon often helps. Being the driver, so that you can feel the slight maneuvers in the steering wheel, helps even more. On an airplane, try to get a window seat in front of the wings — they have the least motion and offer a view. At sea, the least motion is generally in the middle of the ship at water level. The more expensive outer berths with portholes actually can have more motion. Both oral medications and patches are available, over-the-counter and by prescription, to prevent motion sickness. Because these medications prevent, rather than treat, motion sickness, it is important to use them before a trip begins. (Medications to prevent vomiting that don’t specifically target motion sickness usually are ineffective.) It’s a good idea to talk with your doctor before the first time you take any medication for motion sickness. Also note that only a couple of these medications are safe for children. MO — Rear Adm. Joyce Johnson, USPHS-Ret., D.O., M.A., is vice president, Health Sciences, Battelle Memorial Institute, Arlington, Va. Find more health and wellness resources at www .moaa.org/wellness. For submission information, see page 20. PHOTO: STEVE BARRETT 46 MILITARY OFFICER APRIL 2007 http://www.moaa.org/wellness http://www.moaa.org/wellness
For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.