Dizziness & Motion Sickness - How & Why

DIZZINESS AND MOTION SICKNESS – How and Why?

Each year more than million people visit a doctor for dizziness, and an untold number suffer with motion sickness, which is the most common medical problem associated with travel

Dizziness

Some people describe a balance problem, as they feel dizzy, lightheaded, unsteady, or giddy. This feeling of imbalance or disequilibrium, with a sensation of turning or spinning objects going around is sometimes due to an inner ear problem.

Vertigo

Sensation of irregular or whirling motion either of oneself or of external objects. It may result from disease in the labyrinth of the inner ear or the nerve that carries messages from the semicircular canals, utricle, and saccule to the brain. It is derived from Latin verb “to turn”. Equilibrium and balance are affected, and nausea with vomiting may occur as well.

What Is Motion Sickness and Sea Sickness?

Some people may experience nausea and even vomiting when riding in an airplane, automobile, or amusement park ride, and this is called motion sickness. Many people experience motion sickness when riding on a boat or ship, and is called seasickness even though it is the same disorder.

Motion sickness or seasickness is just a minor annoyance and does not signify any serious medical illness, but some travelers feel discomfort by it, and a few even suffer symptoms for a few days after the trip.

The Anatomy of Balance

Dizziness, vertigo, and motion sickness all relate to the sense of balance and equilibrium. Researchers in space and aeronautical medicine call this as a sense of spatial orientation, because it tells the brain where the body is “in space:” and what direction it is pointing, what direction it is moving, and if it is turning or standing still.

The sense of balance is maintained by a complex interaction of the following parts of the nervous system:

• The inner ears (also called the labyrinth), which monitor the directions of motion, such as turning, or forward-backward, side-to-side, and up-and-down motions.
• The eyes, which monitor where the body is in space (i.e. upside down, right side up, etc.) and also directions of motion.
• The skin pressure receptor (somatosensory) such as in the joints and spine (proprioceptors) tells us part of the body is down and touching the ground.
• The muscle and joint sensory receptors, also tells what parts of the body are moving.
• The central nervous system (the brain and spinal cord) also processes all the bits of information from the four other systems to make some coordinated sense out of it all.

The symptoms of motion sickness and dizziness appear when the central nervous system receives conflicting messages from the other four systems.

For example,

1. Suppose when riding through a storm, an airplane is being tossed about by air turbulence. The eyes do not detect all this motion because all you see is the inside of the airplane. The brain then receives messages that do not match with each other. Patient might become “air sick.”
2. Or suppose when sitting in the back seat of a moving car reading a book. The inner ears and skin receptors will detect the motion of the travel, but the eyes see only the pages of book. Then one could become “car sick.”
3. Or, to use a true medical condition as an example, suppose patients suffer inner ear damage on only one side from a head injury or an infection. The damaged inner ear does not send the same signals as the healthy ear. This gives conflicting signals to the brain about the sensation of rotation, and they could suffer a sense of spinning, vertigo, and nausea.

Medical Conditions Causing Dizziness

1. Circulation: If the brain does not get enough blood flow, then one feels light headed. Almost everyone has experienced this on occasion when standing up quickly from a lying down position. But some people have light headedness from poor circulation on a frequent or chronic basis. Arteriosclerosis or hardening of the arteries could cause this, and it is commonly seen in patients who have high blood pressure, diabetes, or high levels of blood fats (cholesterol). It is also seen in patients with inadequate cardiac (heart) function or with anemia.Certain drugs also decrease the blood flow to the brain, especially stimulants such as nicotine and caffeine. Excess salt in the diet also leads to poor circulation. Sometimes circulation is impaired by spasms in the arteries caused by emotional stress, anxiety, and tension.If the inner ear fails to receive enough blood flow, the more specific type of dizziness occurs-that is-vertigo. The inner ear is very sensitive to minor alterations of blood flow and all of the causes mentioned for poor circulation to the brain also apply specifically to the inner ear.
2. Injury: A skull fracture that damages the inner ear produces a profound and incapacitating vertigo with nausea and hearing loss. The dizziness will last for several weeks, and slowly improve as the normal (other) side takes over
3. Infection: Certain viruses, causing infection like the common “cold” or “flu,” can attack the inner ear and its nerve connections to the brain. This can result in severe vertigo, but hearing is usually spared. However, a bacterial infection such as mastoiditis that extends into the inner ear will completely destroy both the hearing and the equilibrium function of that ear. The severity of dizziness and recovery time will be similar to that encountered by a skull fracture.
4. Allergy: Some experience dizziness and/or vertigo attacks when they are exposed to certain food or airborne particles (such as dust, molds, pollens, dander, etc.) to which they are allergic.
5. Neurological diseases: A number of diseases of the nerves can affect balance, such as multiple sclerosis, syphilis, tumors, etc. These are uncommon causes, but the physician will think about them during the examination.

Diagnostic Treatment for Dizziness:

The doctor will ask you to describe the dizziness, whether it is light headedness or a sensation of motion, how long and how often the dizziness has troubled, how long a dizzy episode lasts, and whether it is associated with hearing loss, nausea and vomiting. You might be asked for circumstances that might bring on a dizzy spell. One will need to answer the questions about the general health, any medicines, which we are taking, head injuries, recent infections, and other questions about the ear and neurological system.

The physician will examine the ears, nose, and throat and do tests of nerve and balance function. Besides the inner ear controls both balance and hearing, disorders of balance often affect hearing and vice versa. Therefore, the physician will probably recommend hearing test (audiograms and tympanograms). The physician might order skull X rays, a CT or MRI scan of your head, or special tests of eye motion after warm or cold water is used to stimulate the inner ear (ENG – electronystagmography). In some cases, blood tests or a cardiology (heart) evaluation might be recommended.

Not every patient will require every test. The physician’s judgement will be based on each particular patient. Similarly, the treatments recommended by your physician will depend on the diagnosis.

Steps to Reduce Dizziness:

• Avoid rapid changes in position, especially from lying down to standing up or turning around from one side to the other.
• Avoid extremes of head motion (especially looking up) or rapid head motion (especially turning or twisting).
• Eliminate or reduce use of products that impair circulation, e.g. nicotine, caffeine, and salt.
• Minimize your exposure to circumstances that precipitate your dizziness, such as stress and anxiety or substances to which you are allergic.
• Avoid hazardous activities when you are dizzy, such as driving automobile, operating dangerous equipment, or climbing a step ladder, etc.

What Can I Do for Motion Sickness?

Always ride where your eyes will see the same motion that your body and inner ears feel. E.g. sit in the front seat of the car and look at the distant scenery; go up on the deck of the ship and watch the horizon; sit by the window of the airplane and look outside. In an airplane choose a seat over the wings where the motion is the least.

• Do not read while traveling when subjected to motion sickness, and do not sit in a seat facing backward.
• Do not watch or talk to another traveler who is having motion sickness.
• Avoid strong odors and spicy or greasy foods immediately before and during travel.
• Medical research has not yet investigated the effectiveness of popular folk remedies such as soda crackers and Seven Up or cola syrup over ice.
• Take one of the varieties of motion sickness medicines before travel begins, as recommended by physician.

Some of these medications can be purchased without a prescription (i.e., Avomine, Dramamine, Stemetil) Stronger medicines such as tranquilizers and nervous system depressants will require a prescription from a physician. Some are used in pill or suppository form.

Remember: Most cases of dizziness and motion sickness are mild and self-treatable disorders. But, severe cases and those that become progressively worse deserve the attention of a physician with specialized skills in diseases of the ear, nose, throat, equilibrium, and neurological systems.