Motion Sickness

“You look green” said my guide as I departed my first water plane ride for terra firma. That was an understatement if ever there was one. While my buddies and the pilot took enormous pleasure in the ride through the mountains of British Columbia, I was not experiencing much pleasure at all. I had taken a back seat, being smaller and easier to fit in the back. I could care less as moose and goat were spotted from the air. I was just happy my stomach was empty before we took off, because I am certain the flight would have emptied it otherwise. Motion sickness afflicts some more than others and I am “very sensitive”. In fact in some settings, virtually 100% can be expected to get ill. It is not by accident that the word nausea derives from the Greek word for the ship; naus. Half of all astronauts experience motion sickness. In fact the space shuttle toilet has two setting, one of which is for the consequences of motion sickness.

Despite the common nature of motion sickness, there remains some debate as to its exact biologic cause. Treatment options are also hotly debated with two distinct camps, politely described as traditional and alternative medicine. What we have done here is to provide some basic biologic information, treatments options, and of course preventative strategies. Let’s start by suggesting that you not read this while driving (especially if you are not a passenger).

In its simplest form, motion sickness occurs when the body gets mixed signals from its motion detection systems. This may occur with both real movement and perceived motion such as various “amusement” rides and simulators. There are three major motion detection systems and a group of other neurological inputs lumped together as the “minor” system. Vision is a primary motion detector and plays a significant role in motion sickness. The inner ear contains the other two systems. One, is more well known and is referred to as semi-circular canals. The other inner ear system is the otolith organ. Together these two inner ear apparatuses form the vestibular system. The vestibular system provides us with information related to both angular and translational movement.

Much like a modern day computer, if the software inputs start to argue with each other, the computer no longer functions well. Such is the case with the motion detection systems and their input into various centers in the brain.

A common example of these systems arguing with each other occurs while on a boat hunting with a hook (AKA fishing). Motion, such as waves move the head in a direction perpendicular to the direction of primary movement. Thus the semi-circular canals are giving input that you are going in one direction and the otolith organ says you are going in another direction; hence you feel ill. Car sickness provides for conflict between your vision and your inner ear as far as direction goes. Going back to the computer analogy, your backup system can often save the day in car sickness. Wind in your face allows one of the minor systems to “prove” to the brain what is correct and the conflict is resolved and the symptoms dissipate.

We can adapt to these disturbances over time; hence the expression “getting your sea legs”. Nonetheless this adaptation can take several days of unpleasantness before it kicks in. After you finally get right, be aware that once you return to land, you very quickly lose that adaptation and are just as subject to motion sickness as when you first shoved off.

As complex as this biology maybe, the symptoms of motion sickness are all to well known. First affected is the stomach. It starts with a strange sense of fullness and disquiet. As symptoms progress there is excess salivation and eructation (fancy for burping). Increased sense of bodily warmth follows and if things continue to get worse, overt nausea, sweating and finally emesis (polite for vomiting) and even retching. There is a less common constellation of symptoms characterized by fatigue, headache and social withdrawal although some would argue that with enough nausea and emesis that these other symptoms are only natural and showing social grace!

Skipping the neurobiology lecture, medications for motion sickness target various chemical messengers in the brain. Promethazine and Metoclopramide fall into one category and are very effective. They can be quite sedating however and this must be taken into account. Antihistamines such as diphenhydramine (Benadryl), and Meclizine are also effective, but yet again can be sedating. A different approach is to use a Scopolamine patch. Scopolamine patches target the Cholinergic system. Please be sure to consult your physician before using any of these meds. Like all medications, they can have side effects (beyond sedation) and can interact with other medications you are taking.

Non-traditional approaches are getting more attention these days than ever before. Ginger root either as a powder, tea, or in candied form has many proponents. Most scientific opinion however is unimpressed. Ditto that lack of endorsement for a whole host of seeds and juices on the market for these symptoms. On the other hand, acupuncture techniques have actually been shown to be effective.

These acupuncture approaches have stood up to rigorous scientific study. That having been said, the bracelets and such sold to mimic acupuncture stimulation have not been shown to be effective. This is largely due to inconsistent stimulation. You do not have to use a needle and an actual puncture to get motion sickness relief. Pressure applied to correct point, applied with a purpose and with a continuous nature will work. So where do you rub and press. We will confess to having absolutely no training in acupressure or acupuncture. However on your acupuncture chart the area is called P6. It is located on the pericardial meridian, a little over an inch from the palmar crease. We know how helpful that bit of direction is so we suggest a quick Google to get a better idea of placement so you can self stimulate.

Prevention includes the obvious: getting off the ride, off the water, out of the car, or out of zero gravity results in a rapid return to normal when motion sickness occurs. It seems as if the front of the moving object provides the least confusing stimulation to our brains. Front seat and near a window works in a car, boat, train or plane. As mentioned above wind in the face helps a lot, so use your airplane vent, car window or AC vent. Focusing on the horizon with your head still can reduce symptoms. Do not visually fixate on an object when looking out a side window (or port hole) as this will make things worse. Naturally smoking is not helpful and can aggravate motion sickness.

We hope this review has been helpful. Be safe and enjoy the outdoors.