Vestibular and Balance Disorders
Many thousands of people suffer from dizziness, loss of balance, nausea, vertigo as well as visual and hearing problems – all symptoms of vestibular disorders caused by damage to part of the inner ear. This damage can be from trauma such as a blow to the head or neck injury, a medical situation from middle ear infections and degeneration, headaches or a stroke.
Suffering from dizziness and balance disorders can be severely debilitating and frustrating. We understand. Normal daily activities such as driving, cooking and walking may have to limited or stopped. And conditions can be misunderstood by friends and family. That’s why we listen to our patients and diligently work together to get them back to good health. We do that by first properly identifying and diagnosing your condition, then we work closely with top neurologists, neurotologists, Ear, Nose and Throat specialists, and family practitioners to make sure our treatment programs are best for you.
Understanding your system
Most healthy people take their balance system for granted. Healthy people don't need to think about walking on the beach, or from the sidewalk to the grass, or across the driveway. Healthy people can get out of bed in the middle of the night and find their way around in the dark without stumbling or losing their balance. For people with balance system problems, all of these common, everyday activities are difficult and potentially dangerous. To understand your system you must be familiar with: Sensory Input Integration Motor Output.
Sensory Input
Your ability to maintain your balance depends on information that your brain receives from three different sources: your eyes; the receptors located in your muscles, joints, and skin; and your inner ears. All three of these sources send information in the form of nerve impulses from sensory receptors – special nerve endings – to your brain. These are the sensory inputs that affect balance.
Sensory input from the eyes
Your brain receives a variety of input from your eyes. Special nerve endings or sensory receptors in the back of your eye (the retina) are called rods and cones. These receptors are sensitive to light. When light rays strike them, their nerve fibers send impulses to your brain that provide your brain with visual clues that aid in balance. For example, when walking down a city street, your eyes tell you that the buildings are aligned straight up and down and the sidewalks are straight out in front of you.Sensory input from the muscles, joints, and skin
The input that your brain receives from your muscles and joints comes from sensory receptors that are sensitive to stretch or pressure in the tissues that surround them. As your legs, arms, or other parts of your body move, the receptors respond to the stretch of the muscles surrounding them and send impulses through many nerve fibers to your brain. Sensory receptors in the feet, ankles, knees, and hips sense a change in pressure and send impulses to your brain. These sensors adjust your center of gravity to the surface you are sitting or standing on.
Especially important are the impulses that come from your neck, which indicate the direction in which your head is turned. Impulses from your ankles, knees, and hips indicate the movement or sway of your body in relation to the floor when you are standing or sitting. This kind of input provides your brain with information about the surface you are standing on, such as whether it is hard or soft, bumpy or smooth.
Sensory input from your inner ear
Your inner ear, or labyrinth, is a complex series of passageways and chambers within the bony skull. Within these passageways are tubes and sacs filled with a fluid called endolymph. Around the outside of the tubes and sacs is a different fluid--the perilymph. Both of these fluids are of precise chemical composition, and they are different. The mechanism in your inner ear that regulates the amount and composition of these fluids is very important to the proper functioning of your vestibular system.
Part of each labyrinth, or inner ear, is a snail-shaped organ called the cochlea that functions in hearing. Located right next to the cochlea is the part of the inner ear that has to do with balance; this is called the vestibular apparatus. The vestibular apparatus is found on each side of the head and is composed of three semicircular canals, a utricle, and a saccule.
Each of the semicircular canals is located on a different plane in space. They are located at right angles to each other and to those on the opposite side of your head. At the base of each canal is a swelling (ampulla) and within these ampullae are located the sensory receptors for each canal.
A look inside a semicircular canal reveals the sensory receptor (cupula) that is attached at its base, but remains free at the top. When you move your head in the direction in which the canal is located, the endolymphatic fluid within the canal, because of inertia, lags behind. The same thing happens when you spin a glass of water between your hands. When the fluid lags behind, the sensory receptor within that canal is bent. The receptor then sends impulses to the brain. The receptor is only sensitive while it is actually moving--just like the hairs on your arm. Try to move just one hair--you can feel it bend. When you stop, you don’t feel anything anymore. The same thing happens in the hair cells of the cupula.
When you are healthy and both sides of your vestibular system are functioning properly, the two sides of the vestibular system send impulses to the brain that are symmetrical. That is, the impulses coming from the right side conform to the impulses coming from the left side.
All of the sensory input concerning balance--from the eyes, from the muscles, joints, and skin, and from the two sides of the vestibular system--is sent to a central area below the brain, called the brain stem, where it is sorted out and integrated.
Integration
The brain stem receives input from two other areas of the brain: the cerebellum, which is your coordination center, and the cerebral cortex, which functions in thinking and memory. As the brain stem is integrating all the input it receives concerning balance, the cerebellum may contribute information about automatic movements that have been learned through constant practice, such as adjustments in balance needed to serve a tennis ball.
The cerebral cortex contributes previously learned information. For instance, as a child you learned that icy sidewalks are slippery and that you have to step on them in a different way in order to keep your balance.
Sometimes the integrating activities that take place in the brain stem are more complicated than at other times. For instance, there are times when the sensory input we receive from one of the sources conflicts with the input from other sources. This may occur when you are standing next to a bus that is pulling away from a curb. The visual input from the bus may indicate to your brain that you are moving. In fact, you may find yourself leaning over a little to compensate for that sensation. However, muscles and joints send input that you are not moving, and other visual input finally indicates that other objects are stationary, and your brain makes a correction.
As integration of all the sensory input takes place, the brain stem sends out impulses along motor-nerve fibers that begin in the brain stem and end in the muscles that make your head and neck, eyes, legs, and the rest of your body move. These impulses allow you to maintain balance and have clear vision while moving.
Motor Output
Output to the eyes
The motor impulses that go to your eyeballs coordinate their movement so that you have clear vision while your head is moving either actively (e.g., running or watching a sporting event) or passively (e.g., sitting in a moving car).
While your head is in motion, the movement of your eyes is controlled automatically by your vestibular system. When your head is not moving, the number of impulses from the right side is equal to the number coming from the left side. As a patient turns their head towards the right, the number of impulses from the right semicircular canals increases, and the number from the left decreases; the difference controls eye movements and allows for clear vision as the head turns. You can actually observe the normal fast eye movements (nystagmus) in the light in a person with a healthy vestibular system as they turn their head slowly from left to right and back again. The eyes will move quickly in the same direction as the head turns. These same eye movements occur even in the dark.
Output to the body muscles
The motor impulses that are sent from your brain to the other muscles of your body control their movement so you can maintain your balance whether you are sitting, standing, or turning cartwheels.
Some of the impulses that leave your brain stem go back to the cerebral cortex, carrying information to your thinking centers that tell you its okay to see trees whirling in circles as you turn cartwheels. As you practice these and similar new activities, your brain learns to &qoute;read&qoute; all different kinds of sensory input as normal.
This is exactly what happens as a baby learns to balance through practice and repetition. The impulses from the sensory receptors to the brain stem and out to the muscles form a pathway. With repetition, it becomes easier for the impulses to travel over the same network or pathway, until many activities of keeping your balance become automatic. Physiologists say that these nerve pathways become &qoute;facilitated.&qoute; This is the reason why dancers and athletes practice their activities over and over again. Even very complex movements become almost automatic over a period of time. Anyone who has learned to ride a bicycle, swim, or ski can relate to this idea. This is also the basis for physical therapy in treating people with a damaged vestibular system--the exercises mimic the movements that make them feel less dizzy and lose their balance. After a period of time, the brain &qoute;learns&qoute; that the input from this activity is &qoute;normal&qoute; for the damaged system, and the side effects of dizziness and balance decrease.
Inner Ear Disorders
Many of the symptoms that result from dizziness and balance disorders are obscure and frightening. Although the following symptom list is incomplete and does not apply to everyone with an inner-ear disorder, it may aid many people who have been unable to make sense out of their seemingly &qoute;abnormal&qoute; sensations and symptoms. We hope it is comforting to discover that these symptoms are not imagined, but are very real and caused by a physical problem. The two symptom types associated with inner ear disorders are vision and hearing. To see a listing of these symptoms please check the associated tabs at the top of the page.Vision symptoms
- Objects jump (e.g., silverware jumps off the table, stairs swing).
- Reading is difficult (e.g., print moves, vision blurs or doubles, words or letters switch).
- Writing is difficult.
- Lights glow or emit rays; glare is intensified.
- Discomfort when focusing on distant objects and a tendency to look down.
- Night blindness increases.
- Poor depth perception.
- Moving or flickering lights may be disturbing.
Hearing symptoms
- Hearing fluctuates, is lost completely, or remains unaffected.
- Distortions such as popping, clicking, or buzzing occurs.
- Loud environments cause discomfort or nausea.
- Ears feel " full. "
Types of Therapy
There are two general categories of therapy: adaptive and compensatory. One or both of the categories may be used. Our goal is the patient's quick recovery with long-term results provided in a safe and caring manner.
Adaptive therapy: The adaptive physical therapy strategy helps people who have no permanent central nervous system problems, but who have a vestibular system that is not functioning properly.
Vestibular Rehabilitation
This program is individually designed for patients whose symptoms are generated from the vestibular system. The therapy has two primary goals: safety and improved function. Typically, the patient participates in one or two supervised sessions per week, with an average program of eight to ten sessions that emphasize the use of visual training aids and balance training techniques. As the patient progresses and gains confidence, he or she will be given more difficult tasks and exercises in the office and home to accelerate their improvement. Most patients report a significant reduction of their symptoms within a six to eight week time span.
Home Exercises
This is a home-based program which the patient does on his or her own following a training or instructional session. All patients are given an appropriate home program to reinforce the therapy provided at the clinic. This is probably the most important component to Balance Retraining Therapy (BRT) or Vestibular Rehabilitation. A patient is not spending enough time in the clinic to make a significant difference – the patient must follow through with a home program to make the change.
Balance Retraining
This therapy approach is for individuals who have a loss of balance or unsteadiness. There is an emphasis on practical solutions to the common problems of difficulty moving around in the dark, walking on uneven surfaces, and performing everyday life tasks. We may ask you to repetitively stand in certain positions while doing head and body movements to challenge the balance system. The bottom line is this: Perfect Practice Makes Perfect! If you have an imbalance, you need to practice with good information to learn to gain it back.
Habituation
This type of therapy is for people with positional vertigo and dizziness. The therapy treatment reproduces the eliciting position, repetitiously eliminating the symptom. It is similar to a figure skater spinning or a fighter pilot tolerating flying a jet. You probably have felt the same way when you spun yourself on a chair. It is critical for our patients to experience the environment that provokes their symptoms repetitively until they develop a habituation to the stimulus. What happens with patients with dizziness is that they tend to avoid the movements or environments that provoke symptoms or they take a medication like Meclizine or Antivert that can have significant side effects. I analogize taking Meclizine or even Valium for dizziness like driving your car in the fog. Usually, you can see a few yards in front of you and then everything thong else becomes distorted.
Compensatory therapy: The compensatory approach is for patients who have uncorrectable problems (i.e., stroke, multiple sclerosis, traumatic brain injury). The emphasis is on safety, the use of assistive devices, and modifying the home environment to reduce the potential for accidents.
Sometimes vestibular rehabilitation does not work. Inevitably, there will be some patients where the therapy does not work. This is commonly seen in our patients with significant central balance disorders or when the inner ear dysfunction is what we call &qoute;unstable.&qoute; An unstable inner ear injury that is common is Meniere's disease. Because the disease is fluctuating due to an underlying fluid dysfunction in the inner ear, rehabilitation can actually be a torture versus helpful. Some patients with Meniere's disease can benefit from therapy including endurance, strengthening, and education on diet.
Education
Educating our patients and their families regarding treatment and expectations is a very important part of the program. Providing information through printed materials and videotapes, and support through talking with other recovered or improving patients are all valuable strategies. These patients have often become fearful of doing anything that may provoke an &qoute;attack.&qoute; For many, the entire scope of daily activates has been reduced to those actions they can tolerate performing. Neuro-psychological intervention may be necessary to teach relaxation techniques for coping skills during the rehabilitation process.