Hearing and Balance Disorders
- Discussion of dizziness
- Function of the normal ear
- Maintenance of balance
- Ear or Vestibular dizziness
- Symptoms of ear dizziness
- Central dizziness
- Visual dizziness
- Causes and symptoms of dizziness
- Atypical migraine or basilar migraine
- Benign Paroxysmal Positional Vertigo (BPPV)
- Imbalance related to aging
- Meniere’s disease and endolymphatic hydrops
- Treatment of Meniere's disease and endolymphatic hydrops
- Metabolic disturbances
- Head Injury
- Balance Rehabilitation
The audiologists at Rocky Mountain Hearing and Balance don’t simply treat hearing loss, they also provide solutions for a number of hearing and balance disorders, from symptoms of dizziness to conditions like Meniere’s disease. The following is an overview of several ways an issue in your inner ear can affect your balance.
Discussion of dizziness
Dizziness is a symptom not a disease. It may be defined as a sensation of unsteadiness, imbalance or disorientation in relation to an individual's surroundings. The symptom of dizziness may vary widely from person to person and be caused by many different conditions. It varies from a mild unsteadiness to a severe whirling sensation known as vertigo. As there is little representation of the balance system in the conscious mind, it is not unusual for it to be difficult for the patient to describe their symptom. In addition, because the symptom of dizziness varies so widely from patient to patient and may be caused by many different diseases, testing is often required to be able to provide the patient with some knowledge about the cause of their dizziness. Dizziness may or may not be accompanied by a hearing impairment.
Function of the normal ear
The ear is divided into three parts: external ear, middle ear and inner ear.
The external ear structures gather sound and direct it toward the eardrum. The middle ear chamber consists of an eardrum and three small ear bones. These structures transmit sound vibrations to the inner ear fluid.
The inner ear chamber is encased in bone and filled with fluid. This fluid bathes the delicate nerve endings of the hearing and the balance mechanism.
Fluid waves in the hearing chamber (cochlea) stimulate the hearing nerve endings, which generate an electrical impulse. These impulses are transmitted to the brain for interpretation as sound. Movement of fluid in the balance chambers (vestibule and three semicircular canals) also stimulates nerve endings, resulting in electrical impulses to the brain, where they are interpreted as motion.
Maintenance of balance
The human balance system is made up of four parts, the eye, inner ear, muscles and central nervous system. The brain acts as a central computer receiving information in the form of nerve impulses (messages) from its three input terminals: 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 terminals. All three systems work independently and yet work together to keep the body in balance.
The eyes receive visual clues from light receptors that give the brain information as to the position of the body relative to its surroundings. The receptors in the muscles and joints are called proprioceptors. The most important ones are in the head and neck (head position relative to the rest of the body) and the ankles and joints (body sway relative to the ground).
The inner ear balance mechanism 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 nerve endings that send impulses along the balance nerve to the brain. Those impulses are sent to the brain in equal amounts from both the right and left inner ear. Nerve impulses may be started by the semicircular canals when turning 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 the inner ear is not functioning correctly the brain receives nerve impulses that are no longer equal, causing it to perceive this information as distorted or off balance. This imbalance of nerve impulses from the ears to the brain can cause an eye move called nystagmus, which is often perceived as a spinning or motion sensation.
Remember to think of the brain as a computer with three input terminals feeding it constant up-to-date information from the eye, inner ear and muscles and joints (proprioceptors). The brain itself is divided into several different parts. The most primitive area is known as the brainstem, and it is here that processing of the input from the three sensory terminals occurs. 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.
The brainstem receives all these nerve impulses: sensory from the eyes, inner ear, muscles and joints; regulatory from the cerebellum; and voluntary from the cerebral cortex. The information is then processed and fed back to the muscles of the body to help maintain a sense of balance.
Because the cortex, cerebellum and brainstem can eventually become used to (able to ignore) abnormal or unequal impulses from the inner ear, exercise may be helpful. Exercise often helps the brain to habituate 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 habituation is seen with the ice skaters who twirl around, stop suddenly, and do not apparently have any balance disturbance.
Ear or Vestibular dizziness
Ear dizziness, one of the most common types of dizziness, results from disturbances in the blood circulation or fluid pressure in the inner ear chambers, from direct pressure on the balance nerve or physiologic changes involving the balance nerve or balance mechanisms. Inflammation or infection of the inner ear or balance nerve is also a major cause of ear dizziness.
Any disturbance in pressure, consistency or circulation of the inner ear fluids may result in acute, chronic or recurrent dizziness, with or without hearing loss. 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 an over stimulation of the inner ear fluids, which may be encountered if you spin very fast and then stop suddenly.
Symptoms of ear dizziness
Any disturbance affecting the function of the inner ear or its central connections may result in dizziness, hearing loss or tinnitus (head noise). These symptoms may occur singly or in combination, depending upon which functions of the inner ear are disturbed.
Ear dizziness may appear as a whirling or spinning sensation (vertigo), unsteadiness or giddiness and 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 you should 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 states, and excessive alcohol intake. Circulatory inefficiency, tumors or injuries may produce this type of unsteadiness, with or without hearing impairment. A feeling of pressure or fullness in the head is common. Occasionally true vertigo (spinning) may be caused by central problems.
Eye Muscle imbalance or errors of refraction may produce unsteadiness. An example of this is the unsteadiness, which may result when you attempt to walk while wearing glasses belonging to another individual.
Another example of visual dizziness is that occasionally produced if you are 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 indicating that the body is rotating. On the other hand, the ears and the muscle-joint systems send impulses to the brain indicating that the body is not rotating, only moving forward. The brain, receiving these confused impulses (from the eyes indicating rotation, from the ears and muscle-joint systems indicating forward motion) sends out equally confusing orders to various muscles and glands that may result in sweating, nausea and vomiting. When you sit in the front seat looking forward, the eyes, ears and muscle- joint systems work more uniformly, making it less likely to develop carsickness.
Causes and symptoms of dizziness
Dizziness may be caused by any disturbance in the inner ear, the balance nerve or its central connections. This can be due to a disturbance in circulation, fluid pressure or metabolism, infections, inflammation/neuritis, drugs/medications, injury or growths.
At times an extensive evaluation is required to determine the cause of dizziness and may include detailed hearing and balance tests, scans, x-rays, and blood tests, as directed by your physician. 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.
Atypical migraine or basilar migraine
Inner ear dizziness due to blood vessel spasm is usually sudden in onset and intermittent in character. It may occur as an isolated event in the patient's life or repeatedly in association with other symptoms. If it is recurrent it usually is associated with migraine headache-type symptoms. Predisposing causes include fatigue and emotional stress. Certain drugs such as caffeine (coffee) and nicotine (cigarettes) tend to produce blood vessel spasm or constriction and should be avoided. Blood vessel spasm has been noted to occasionally begin after head injury. Although there may have been no direct injury to the inner ear by the trauma, the spasm may begin to damage the ear.
Blood Vessel occlusion
As you get older, blood vessel walls tend to thicken due to an aging process known as arteriosclerosis. This thickening results in partial occlusion, with a gradual decrease of blood flow to the inner ear structures. The balance mechanism usually adjusts to this, but at times persistent unsteadiness develops. This may be aggravated by sudden position changes such as that encountered when you get up quickly or turn suddenly.
Complete occlusion of an inner ear blood vessel (thrombosis) results in acute dizziness often associated with nausea and vomiting. Symptoms may persist 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.
Benign Paroxysmal Positional Vertigo (BPPV)
BPPV is a common form of balance disturbance due to loose calcium deposits (Canalith) in the inner ear. It is characterized by sudden, brief episodes, typically described as vertigo (spinning), when moving or changing head position. Commonly it is noticed when lying down or arising or when turning over in bed. This type of dizziness as its names suggests is benign, related to positional changes and is short-lived. The vertigo brought on by the movement rarely lasts more than a few minutes, and responds well to treatment. However, it may reoccur in some patients. Treatment involves attempts to reposition the loose calcium deposits (Canalith) and keep the dizziness from occurring (Canalith Repositioning Procedure). The is one of the most common forms of vertigo identified and treated at Rocky Mountain Hearing & Balance.
Imbalance related to aging
Some individuals develop imbalance as a result of the aging process. In many cases this is due to circulatory changes in the very small blood vessels supplying the inner ear and balance nerve mechanism.
Postural or positional vertigo (see above) is the most common balance disturbance of aging. This may develop in younger individuals as a result of head injuries. Dizziness on change of head position is a distressing symptom, which is often helped by vestibular exercises.
Temporary unsteadiness upon arising from bed in the morning is not uncommon in older individuals. At times this feeling of imbalance may persist for an hour or two. Arising from bed slowly usually minimizes the disturbance. Unsteadiness when walking, particularly on stepping up or down or walking on uneven surfaces, develops in some individuals as they progress in age. Balance rehabilitation services may be an appropriate course of action to improve stability and reduce fall risk.
Neuritis is a physiological change that occurs in the nerve after injury by trauma, a virus, autoimmune disease or vascular compression. When this occurs, the balance function is impaired, resulting in a severe, and at times prolonged, episode of dizziness, often followed by some unsteadiness or motion for weeks to months. Fortunately, this balance disturbance usually subsides in time and usually does not recur in the majority of cases. It may be, however, very chronic at a moderate to mild level. With time, the central nervous system can compensate for the damage. Vestibular or balance rehabilitation services may be an appropriate course of action to improve stability and reduce fall risk. These services will also speed up the compensation process.
Meniere’s disease and endolymphatic hydrops
Meniere's disease is a common cause of repeated attacks of dizziness and is thought to be due to (in most cases) increased pressure of the inner ear fluids due to impaired metabolism of the inner ear. Fluids in the inner ear chamber are constantly being produced and absorbed by the circulatory system. Any disturbance of this delicate relationship results in overproduction or underabsorption of the fluid. This leads to an increase in the fluid pressure (hydrops) that may, in turn, produce dizziness that may or may not be associated with fluctuating hearing loss and tinnitus.
A thorough evaluation is necessary to determine the cause of Meniere's disease. Circulatory, metabolic, toxic and allergic factors may play a part in any individual. Emotional stress, while making the disease worse, does not cause Meniere’s disease. Meniere's disease is usually characterized by attacks consisting of vertigo (spinning) that varies in duration from a several minutes to several hours. Hearing loss and head noise (tinnitus), usually accompanies the attacks. Violent spinning, whirling, and falling associated with nausea and vomiting are common symptoms. Sensations 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 overt spinning stops. Attacks of dizziness may recur at irregular intervals and the individual may be free of symptoms for years at a time, only to have them recur again.
Occasionally hearing impairment, head noise (tinnitus), and ear pressure occur without dizziness. This type of Meniere's disease is called cochlear hydrops. Similarly, episodic dizziness and ear pressure may occur without hearing loss or tinnitus, and this is called vestibular hydrops.
Endolymphatic hydrops is a term that describes increased fluid pressure in the inner ear. A special clinical 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. A person may have one symptom or a combination of signs. Often there is a combination of hearing changes, disequilibrium, motion intolerance or short dizzy episodes. There may be tinnitus and/or a pressure feeling in the head or ears. The patient 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 blurred and 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. A combination of dietary management and medications such as diuretics are commonly used. The purpose is to decrease the fluid pressure in the inner ear. In addition to diuretics, other medications may be indicated, depending on the cause of symptoms in each patient's case.
Treatment of Meniere's disease and endolymphatic hydrops
Treatment of cochlear and vestibular hydrops is the same as for classic Meniere's disease. Treatment is aimed at improving inner ear circulation and controlling the fluid pressure changes of the inner ear chambers. Medical treatment of Meniere's disease varies with the individual patient according to suspected cause and magnitude and frequency of symptoms. Treatment may consist of dietary restrictions and medication to decrease the inner ear fluid pressure. Vasoconstricting substances have an opposite effect and, therefore, should be avoided. Such substances are caffeine (coffee) and nicotine (cigarettes). Diuretics (water pills) may be prescribed to decrease the inner ear fluid pressure. On rare occasions, gentamycin injections may be used to selectively destroy balance function.
Occasionally metabolic disturbances produce dizziness with or without associated hearing loss by interfering with the function of the inner ear or the central nervous system. Occasionally hearing loss may occur without the presence of dizziness.
A change of thyroid function or abnormalities in the blood sugar are the most common metabolic disturbances resulting in dizziness. Rarely, fat metabolism abnormalities may also cause problems resulting in hearing loss and/or dizziness. Thyroid dysfunction is diagnosed by blood tests and treatment consists of taking a thyroid hormone. Abnormalities in the blood sugar are diagnosed, again by blood studies and treatment usually consists of diet control and/or drug therapy. Fat metabolism problems are diagnosed by studies of the fatty acids and cholesterol in the blood. Treatment of these may consist of diet control with or without drug therapy.
Injury to the head occasionally results in dizziness of long-standing origin. If the trauma is severe, it is usually due to the combined damage to the inner ear, balance nerve and central nervous system. Lesser injury may damage any one, or a combination of these components. The unsteadiness is at times prolonged, and may or may not be associated with hearing loss and head noise (tinnitus) as well as other symptoms.
A noncancerous tumor occasionally develops on the balance nerve between the ear and the brain. When this occurs, unsteadiness, hearing loss and head noise (tinnitus) may develop. Extensive hearing tests, balance tests and scans or x-rays are necessary to diagnose such tumors. If the diagnosis of a tumor is established, surgical removal is may be recommended depending stage and size of the growth. Additionally, periodic monitoring of the growth may be recommended. Commonly you will see a neurotologist in the process of diagnosis, who can provide recommendation about appropriate treatments options.
Typically, a physical therapist evaluation of patients with vestibular or balance disorders takes approximately 60-90 minutes. The evaluation begins with a history, including details about symptoms, general activity level and medications that the patient is currently taking. Range of motion, strength, coordination, balance and various sensory systems are also assessed.
Following the evaluation, a treatment plan is developed. The treatment plan may consist of habitual exercises for dizziness, balance retraining exercise and usually a general strengthening of muscles involved in maintaining good stability. The goal of habituation exercises is to decrease the patient's symptoms of motion provoked dizziness or lightheadedness while balance retraining or rehabilitation focuses on improving stability and reducing fall risk.