Dizziness may be defined as a sensation of unsteadiness, imbalance or disorientation in relation to an individual’s surroundings. The symptom of dizziness may vary greatly from person to person, and may be caused by many difference things. It varies from a mild unsteadiness to a severe whirling sensation known as vertigo. It may be difficult for the individual to describe the symptoms of dizziness to a physician. Because symptoms vary and can be caused by different diseases, a physician commonly requires testing to be able to provide the individual with some knowledge about the cause of the dizziness. Dizziness may or may not be accompanied by a hearing loss.
MAINTENANCE OF BALANCE
The human balance system is made up of four parts. The brain acts as a central computer receiving information in the form of nerve impulses (messages) from its three input centers of the body: the eyes, the inner ear, and the muscles and joints of the body. There is a constant stream of impulses arriving at the brain from these input sources. All three systems work independently, yet together to keep the body in balance.
The eyes receive visual clues from light receptors that give the brain information about the body in its surroundings. The receptors in the muscles and joints are called proprioceptors. The most important ones are in the head, neck, ankles and joints.
The inner ear balance organ has two main parts: three semicircular canals and the vestibule. Together they are called the vestibular labyrinth and are filled with fluid. When the head moves, fluid within the labyrinth moves and stimulates nerves that send impulses along the balance nerve to the brain. Nerve impulses may be sent from the semicircular canals when the head turns suddenly, or the impulses may come from the vestibule, which responds to changes of position, such as lying down, turning over, or getting out of bed.
When one inner ear is not functioning correctly, the brain receives messages that are unequal, causing it to interpret the information as distorted or off balance. The brain sends messages to the eyes, causing them to move back and forth (called nystagmus), making the surroundings appear to spin.
Remember to think of the brain as a computer with three input terminals feeding it constant up-to-date information. The brain is divided into several different parts. The lower part of the brain is the brainstem, and it is here that the information from the eyes, ears and proprioceptors is processed. The information is then processed and fed back to the muscles of the body to help maintain a sense of balance.
The brainstem is affected by two other parts of the brain, the cerebral cortex and the cerebellum. The cerebral cortex is where past information and memories are stored. The cerebellum, on the other hand, provides automatic (involuntary) information from activities which have been repeated often. Because the cortex, cerebellum and brainstem can eventually become used to abnormal or unequal impulses from the inner ear, exercise may be helpful. Exercise often helps the brain to get used to the dizziness problem so that is does not respond in an abnormal way and does not result in the individual feeling dizzy. An example of this is seen when ice skaters twirl around, stop suddenly, and do not apparently have any balance disturbance.
TYPES OF DIZZINESS
Sensations of unsteadiness, imbalance or disorientation in relationship to one’s surroundings may result from disturbances in the ear, neck, muscles and joints, eyes, the nervous system or a combination of any of the above.
Ear dizziness, one of the most common types of dizziness, results from disturbances in the blood circulation or pressure of fluid in the inner ear chambers. There can be direct pressure on the balance nerve or physiologic changes involving the balance nerve. Inflammation or infection of the inner ear or balance nerve is also a major cause of ear dizziness.
The inner ear mechanism is about the size of a pea and is extremely sensitive. There are two inner ear chambers: One for hearing (cochlea), and one for balance (vestibule and semicircular canals). These chambers contain a fluid which bathes the delicate nerve endings. These nerve endings are stimulated when there is movement of the fluid. Nerve impulses are then transmitted to the brain by the hearing and balance nerves. The nerves pass through a small bony canal (internal auditory canal), accompanied by the facial nerve.
Any disturbance the inner ear fluids may result in dizziness, hearing loss and ringing in the ears (tinnitus). Likewise, any disturbance in the blood circulation to this area or infection of the region may result in similar symptoms. Dizziness may also be produced by over-stimulation of the inner ear fluids, such as when one spins very fast and stops suddenly.
Symptoms of Ear Dizziness
Any disturbance affecting the function of the inner ear or its connections in the brain may result in dizziness, hearing loss or tinnitus. These symptoms may occur alone or in combination, depending upon which parts of the inner ear are disturbed. Ear dizziness may appear as a whirling or spinning sensation (vertigo), unsteadiness or lightheadedness. It may be constant, but is more often intermittent, and is frequently aggravated by head motion or sudden positional changes. Nausea and vomiting may occur, but one does not lose consciousness as a result of inner ear dizziness.
Central dizziness is usually an unsteadiness brought about by failure of the brain to correctly coordinate or interpret the nerve impulses which it receives. An example of this is the “swimming feeling” or unsteadiness that may accompany emotional stress, tension, and excessive alcohol intake. Circulatory inefficiency, tumors, or injuries may produce this type of unsteadiness, with or without hearing loss. A feeling of pressure or fullness in the head is common.
Neck Dizziness (cervical vertigo) results from abnormal or uncoordinated nerve impulses being sent to the brain from the neck muscles. The neck muscles are constantly sending nerve impulses to the balance centers of the brain to help maintain balance. Spasms of the muscles may result in an abnormal nerve release, leading to unsteadiness or dizziness. These spasms may result from injury, arthritis of the spine, or from pressure on nerves in the neck.
Muscle-joint dizziness is relatively uncommon. Any disturbance of sensation coming from the muscles and joints in the limbs produces this type of unsteadiness. One example of this kind of unsteadiness is when one tries to walk on a leg that has “gone to sleep.”
An imbalance of the eye muscles or errors from the light receptors in the eyes may produce unsteadiness. An example of this unsteadiness is when one attempts to walk while wearing glasses belonging to another individual. Another example of visual dizziness is when one is seated in a car looking out the side window at passing objects. The eyes respond by sending a rapid series of impulses to the brain telling it that the body is rotating.
On the other hand, the ears and the muscle-joint systems send impulses to the brain telling it that the body is not rotating, only moving forward. The brain, receiving these confused impulses, sends out equally confusing orders to various muscles and glands that may result in sweating, nausea and vomiting. When a person sits in the front seat looking forward, the eyes, ears, and muscle- joint systems work better together and the person is less likely to develop car sickness.
A visual disturbance may be caused by dizziness from other sources. These include the inability to focus the eyes, difficulty reading or blurring of vision. Anxiety or tension may result in small movements of the eye called nystagmus. This nystagmus is common during severe dizziness.
People who are prone to dizziness should use caution when swimming. Buoyancy of the water results in an essentially weightless condition, and visual orientation is greatly impaired if the person’s head is under water. As a result, orientation depends almost entirely on the inner ear balance organ. An attack of dizziness at this time could be very dangerous. Similarly, individuals who have lost both inner ear balance organs should avoid underwater swimming.
DIAGNOSING THE CAUSE OF DIZZINESS
Dizziness may be caused by any disturbance in the inner ear, the balance nerve or its connections in the brain. This can be due to a disturbance in circulation, fluid pressure, infections, drugs, injury, or growths.
At times, an extensive evaluation is required to determine the cause of dizziness. The tests necessary may include detailed hearing and balance tests, x-rays or blood tests. A general physical examination and neurological tests may be advised.
The object of this evaluation is to be certain that there is no serious or life-threatening disease and to pinpoint the location of the problem. This lays the groundwork for effective medical or surgical treatment.
Any interference with the blood supply to the inner ear structures or their connections in the brain may result in dizziness and, at times, hearing loss and tinnitus. These circulatory changes may be the result of blood vessel spasm, partial or total blockage, or a rupture with hemorrhage.
Blood Vessel Spasm
Inner ear dizziness due to a blood vessel spasm usually happens suddenly and is intermittent. It may occur once in the patient’s life or repeatedly with other symptoms. If it is recurrent it usually is associated with migraine headache symptoms. Some causes include fatigue and emotional stress. Certain drugs such as caffeine (coffee) and nicotine (cigarettes) tend to produce blood vessel spasms or constriction and should be avoided. Blood vessel spasms have been noted to occasionally happen after a head injury. Although there may have been no direct injury to the inner ear by the trauma, the spasm may begin and damage the ear.
As one gets older, blood vessel walls tend to thicken due to an aging process known as arteriosclerosis. This thickening results in a partial blockage, with a gradual decrease of blood flow to the inner ear structures. The balance organ usually adjusts to this, but at times persistent unsteadiness develops. This may be aggravated by sudden position changes such as when one gets up quickly or turns suddenly.
Complete blockage of an inner ear blood vessel results in severe dizziness often associated with nausea and vomiting. Symptoms may continue for several days, followed by a gradual decrease of dizziness over a period of weeks or months as the central nervous system and uninvolved ear compensates for the loss of the involved ear.
Occasionally, one of the small blood vessels of the balance mechanism breaks. This may occur spontaneously, for no apparent reason, or it may be the result of high blood pressure or head injury. Symptoms are the same as those of occlusion.
Treatment for Circulation Changes
Treatment of dizziness because of changes in circulation can include anti-dizziness medications, which help lessen the symptoms. They also stimulate blood circulation and help the brain to control the symptoms on its own. An individual with this type of dizziness should avoid drugs that constrict the blood vessels, such as caffeine (coffee) and nicotine (cigarettes). Emotional stress, anxiety and excessive fatigue should be avoided as much as possible. Often, increased exercise will aid in making the dizziness better by stimulating the remaining function to be more effective.
BENIGN POSITIONAL VERTIGO
Postural or Positional Dizziness
Postural or positional dizziness is a common balance problem due to circulatory changes or loose calcium deposits in the inner ear. It is characterized by sudden, brief episodes of imbalance when moving or changing head position. It is commonly noticed when lying down, turning over or getting out of bed. This type of dizziness rarely gets worse and usually responds to treatment. If this dizziness is treated, it may recur at a later time. Treatment usually consists of exercises designed to intensify the dizziness until it fatigues. This type of exercise may be recommended by a physician to cause the dizziness to run its course more quickly. Occasionally, postural dizziness may be permanent, and surgery may be required.
IMBALANCE RELATED TO AGING
Some individuals develop imbalance as a result of aging. In many cases this is due to circulatory changes in the very small blood vessels that carry blood to the inner ear and balance nerve. Fortunately, these disturbances rarely become worse. Postural or positional vertigo (see above) is the most common balance disorder due to aging. This may develop in younger individuals as a result of head injuries or blood disturbances. Dizziness on change of head position is a distressing symptom, which is often helped by exercises.
Temporary unsteadiness upon arising from bed in the morning is not uncommon in older individuals. At times, this feeling of imbalance may last for an hour or two. Slowly rising from bed usually minimizes the feelings of dizziness. Unsteadiness when walking, particularly when stepping up or down or walking on uneven surfaces, develops in some individuals as they age. Using a cane and learning to use vision to steady your balance is often helpful.
Imbalance due to an ear infection is usually mild in onset. Such imbalance may occur with or without hearing loss. As the infection gets closer to the balance organ, the dizziness becomes more constant and severe in nature, and is often associated with nausea and vomiting.
Making sure that an ear infection is under control is important with this type of dizziness so that infection does not spread directly into the balance organ of the inner ear. If this happens, serious complications, including total loss of hearing in the infected ear, may result. If the infection cannot treated by medical management, surgery may be a last resort to remove the infection.
In rare cases, allergies may cause dizziness, vertigo or both. Allergies are usually diagnosed by obtaining a careful history and sometimes performing a series of skin tests or blood tests. Treatment usually consists of eliminating the allergens when possible, or, if this is not possible, by allergy shots to stimulate immunity.
Injury to the head occasionally results in dizziness. If the trauma is severe, there is usually combined damage to the inner ear, balance nerve, and central nervous system. A less-severe injury may damage one or more of these components. The unsteadiness can be prolonged, and may or may not be associated with hearing loss and tinnitus as well as other symptoms.
Trauma and Brain Damage
In severe trauma, the base of the brain or the cerebellum may be injured. These structures are slow to heal, and there is often a residual dizziness that does not get better with treatment. Fortunately, the symptoms are usually relatively mild. Medication is not often beneficial, but rehabilitation therapy can be quite helpful.
A perilymphatic fistula is a leak of inner ear fluid into the middle ear space. Minor closed-head injuries may cause a fistula between the middle ear space and the inner ear. Fistulas change the pressure in the inner ear and lead to a variety of symptoms, some of which can be debilitating. Persistent daily low-grade dizziness is often associated with fistulas, but the person may also experience severe episodes of vertigo similar to those seen in Meniere’s disease. Surgery is usually required to close a fistula and stop the symptoms. If the fistula is large or has been present for some time, there may be permanent damage to the inner ear, and symptoms may continue even after closure of the fistula. In these extreme cases, cutting the vestibular nerve is necessary to stop the persistent dizziness.
A noncancerous tumor occasionally develops on the balance nerve between the ear and the brain. When this occurs, unsteadiness, hearing loss and tinnitus may develop. Extensive hearing tests, balance tests and imaging tests are necessary to diagnose these tumors.
If the diagnosis of a tumor is established, surgical removal is imperative. Continued growth of the tumor would lead to complications by producing pressure on vital nerves and the brain. An operation has been developed to remove these tumors at an early stage. Best results can be obtained if the tumor is diagnosed early and removed while the only symptoms are hearing loss, dizziness, and tinnitus.
Endolymphatic hydrops is a term which describes increased fluid pressure in the inner ear. A special form of endolymphatic hydrops is called Meniere’s disease. All patients with Meniere’s disease have endolymphatic hydrops, but not all patients with hydrops have Meniere’s disease.
There may be many causes of endolymphatic hydrops. It may be caused or aggravated by excessive salt intake or certain medications. The symptoms are highly variable. Often there is a combination of hearing loss, disequilibrium, motion sickness or dizziness. There may be tinnitus and a feeling of pressure in the head or ears. The patient with hydrops does not have the well-defined attacks of Meniere’s disease (fluctuating hearing loss, tinnitus and episodes of spinning lasting minutes to hours). Often the division between the two diagnoses may be difficult to separate, even for the patient. Endolymphatic hydrops may progress to Meniere’s disease in some patients.
The treatment of endolymphatic hydrops is similar to that for Meniere’s disease. Medications such as diuretics (water pills) are used, depending on the patient’s symptoms. If medications fail, surgery is sometimes recommended.
Meniere’s disease is a common cause of repeated attacks of dizziness, and is thought to be due to increased pressure of the inner ear fluids. Any disturbance of this fluid balance results in overproduction or under-absorption of the fluid. This leads to an increase in the fluid pressure (hydrops) that may cause dizziness and fluctuating hearing loss and tinnitus. A thorough evaluation is necessary to determine the cause of Meniere’s disease, if possible.
Meniere’s disease is usually characterized by attacks consisting of vertigo (spinning) that lasts from a few minutes to several hours. Hearing loss and tinnitus may occur suddenly with the vertigo. Violent spinning, whirling, and falling associated with nausea and vomiting are common symptoms. Feelings of pressure and fullness in the ear or head are usually present during the attacks. The individual may be very tired for several hours after the spinning stops.
Attacks of dizziness may recur at any time. The individual may be free of symptoms for years at a time, only to have them happen again. In between major attacks, the individual may have minor episodes occurring more often.
Occasionally hearing impairment, tinnitus and ear pressure occur without dizziness. This type of Meniere’s disease is called cochlear hydrops. Similarly, episodes of dizziness and ear pressure may occur without hearing loss or tinnitus, and this is called vestibular hydrops.
Treatment of Meniere’s Disease
Treatment of cochlear and vestibular hydrops is the same as for classic Meniere’s disease. The treatment of Meniere’s disease depends on the patient’s stage of the disease, life circumstances, and the condition of the ears. The purpose of the treatment is to prevent the hearing loss and stop the spinning. Treatment is meant to control the fluid pressure changes of the inner ear. At times, it is necessary to surgically cut the balance nerve or remove the inner ear structures.
Medical treatment is effective in decreasing the frequency and severity of attacks in 80% of patients. Treatment may consist of medication, changes to diet and lifestyle, and, on rare occasions, injections of antibiotics into the middle ear space. This treatment is reserved for patients with Meniere’s disease in their only hearing ear or with Meniere’s disease in both ears.
Surgical Treatment for Dizziness
Surgery may be needed when medical treatment does not control the vertigo. The type of operation depends on the degree of hearing loss, the life circumstances of the individual, and the status of the individual’s disease. In some surgeries, the hearing may be occasionally improved following surgery, and in others it may become worse. Tinnitus may get better or worse, but in most cases it is not relieved.
Surgery is most successful in relieving severe attacks of dizziness in the majority of patients. Some unsteadiness may continue over a period of several months until the nervous system and other ear are able to compensate and stabilize the balance system.
Surgery does have its own risks and complications, which should be discussed with a physician.
Nonsurgical Treatment for Dizziness
Current research indicates that patients who undergo vestibular rehabilitation do quite well (Hillier & Hollohan, 2007). A physical therapist evaluates and treats patients with vestibular or balance disorders. The evaluation begins with a history of the patient’s symptoms. This includes how long the patient has been experiencing the dizziness, how long the symptoms last, general activity level and medications that the patient is currently taking. Physical balance and coordination and various sensory systems are also assessed. One of the most difficult things for patients with vestibular disorders to do is walk and move the head. Different combinations of head and neck movements are performed during walking to provoke symptoms.
Following the evaluation, a treatment plan is developed. The treatment consists of exercises, balance retraining exercise, and usually a general conditioning program. The goal of the exercises is to decrease the patient’s symptoms of motion-provoked dizziness. The exercises are chosen to address the patient’s particular problems that were discovered during the evaluation. These exercises use repetitive movements to fatigue the response of the vestibular system. This, in turn, increases the patient’s tolerance for these movements.
Balance retraining exercises can also be given to improve the patient’s balance. Exercises are chosen based on the problem areas discovered in the evaluation and often involve using vision, motion or sensations from the joints and muscles, as well as the inner ear. The patient may be asked to perform exercises with eyes closed or standing on a soft surface. The patient must consistently perform all the exercises in their treatment program to achieve the goals of improving their balance and decreasing their dizziness.
There are many causes of dizziness. This dizziness may or may not be associated with hearing loss. In most instances, the distressing symptoms of dizziness can be greatly benefited or eliminated by medical, surgical or rehabilitative management.
Hillier, S. L., & Hollohan, V. (2007). Vestibular rehabilitation for unilateral peripheral vestibular dysfunction (Cochrane Review). In The Cochrane Collaboration (Issue 4).Chichester, England: Wiley.