Timothy C. Hain, MD,
Last updated: 2/02. Please read our disclaimer.
Motion sickness is the nausea, disorientation and fatigue that can be induced by head motion. The first sign is usually pallor. Yawning, restlessness and a cold sweat forming on the upper lip or forehead often follow. As symptoms build, an upset stomach, fatigue or drowsiness may occur. The final stages are characterized by nausea and vomiting.
Motion sickness is common and normal. Nearly anyone can be made motion sick by an appropriate stimulus, except for individuals with no vestibular system (William James). In a large study done in India, the prevalence of motion sickness was about 28%, and females were more susceptible (27%) were more susceptible than males (16.8%). Individuals with more active occupations are less susceptible (Sharma, 1997). In medical transport personnel, 46% of personnel reported nausea and 65%, the sopite syndrome (sleepiness caused by motion). (Wright, 1995)
What Causes Motion Sickness ?
In order for the body to determine where it is at all times, the brain combines visual information, touch information, inner ear information, and internal expectations. Under most circumstances, the senses and expectations agree. When they disagree, there is conflict, and motion sickness can occur.
For example, consider the situation when one is reading in the back seat of a car. Your eyes, fixed on the book, say that you are still. However, as the car goes over bumps and accelerates/decelerates, your ears disagree. This is why motion sickness in this situation is common.
Acquired susceptibility to motion sickness occurs occasionally. Persons with an inner ear disturbances, especially a recent one, may be intolerant to activity in general. People with migraine are apt to get motion sick. Persons with rare, central nervous system disorders of the part of the brain that processes signals from the inner ear may also be unusually susceptible to motion sickness. Certain individuals who are constitutionally susceptible to motion sickness and can develop sea sickness on ships, and a prolonged land sickness, when they get off the ship. This rare disorder is called "mal de debarquement", which is French for "bad getting off the ship". Persons with unusually good vestibular function may be more susceptible to motion sickness than others (Gordon et al, 1996).
Migraine is a definite risk factor for motion sickness, with roughly a 5 fold greater incidence than non-migraineurs. Female gender and youth is also a risk factor. In women, days 9-15 appear to have a higher incidence of nausea (Ramsay, 1994).
Experimentally, motion-sickness can be eliminated in dogs by surgically removing part of the brain (the nodulus, according to Bard).
There are essentially three strategies to treatment of motion sickness:
Behavioral Strategies for Motion Sickness
Medication for Motion Sickness
Most medications for motion sickness need to be taken at least 30 minutes before exposure to the activity that can cause the problem. Persons with glaucoma or prostate problems should not take most of these medications unless so advised by their doctor.
Treatment of motion sickness differs from treatment of nausea and vomiting. A discussion of emesis can be found here.
There are several devices that purport to reduce motion sickness through stimulation of various places on the body (usually the wrist). These include "Sea Bands" and "Relief Band", among others. These devices may be placebo's, but so what.
There are numerous "alternative" remedies for motion sickness. The most popular are Ginger derivatives, such as ginger tea, powdered ginger capsules, and even raw ginger between the teeth.
See also: http://www.sciam.com/askexpert_question.cfm?chanID=sa005&articleID=00007F4B-D6FD-1E4B-967D809EC588EEDF