M-2: Vestibular Disorders: What Are They? The vestibular system is the part of the inner ear and the brain that helps control balance and eye movements. When the inner ear or the brain are damaged by disease or injury, vestibular disorders can result. The most commonly diagnosed vestibular disorders include positional vertigo (also called BPPV, BPPN, or BPV), Meniere's disease, infections of the inner ear (called labyrinthitis or vestibular neuronitis), injury caused by head blows (called inner ear concussion syndrome), endolymphatic hydrops, and perilymph fistula. Other, rarer disorders include slow- growing tumors on the vestibular nerve (called acoustic neuromas) and vestibular disorders associated with allergic or autoimmune disorders. What Are the Symptoms of Vestibular Disorders? The most frequently reported symptoms of vestibular disorders are dizziness, unsteadiness or imbalance when walking, vertigo, and nausea. These symptoms may be quite mild, lasting minutes, or quite severe, resulting in total disability. Because the vestibular system interacts with many other parts of the nervous system, symptoms may also be experienced as problems with vision, muscles, and thinking, and memory. In addition, people with vestibular disorders may suffer headache and muscular aches in the neck and back, increased tendency to suffer from motion sickness, and increased sensitivity to noise and bright lights. Patients with vestibular disorders often report fatigue and loss of stamina and an inability to concentrate. Difficulty with reading and speech may occur during times of fatigue. When these symptoms are constant and disabling, they may be accompanied by irritability, loss of self-esteem, and/or depression. Who Is at Risk? Vestibular disorders occur frequently and can affect people of all ages and all walks of life. According to studies from the National Institutes of Health, 90 million Americans (42% of the population) will complain to their doctors of dizziness at least once in their lifetime. In 76 million of these people, the cause of the problem will lie in the inner ear. The National Ambulatory Medical Care Study (1988) found that in 1985 alone, 5,267,000 Americans sought medical help for dizziness. An estimated half million of these patients were severely disabled by their symptoms. The full cost of vestibular disorders to society in terms of medical expenses and lost productivity is still unknown. What Causes Vestibular Disorders? Blows to the head and whiplash are a frequent cause of vestibular disorders in people under age 50. Ear infections such as otitis media and inflammation of the inner ear (labyrinthitis) may also cause damage to the vestibular and hearing structures of the inner ear. Viruses may cause some vestibular disorders. High doses or long-term use of certain antibiotics can also cause permanent damage to the inner ear. Other drugs, such as aspirin, caffeine, alcohol, nicotine, sedatives, and tranquilizers, as well as many illegal drugs, can cause temporary dizziness but do not result in permanent damage to the vestibular system. If the flow of blood to the inner ear or the brain is reduced or blocked (as in the case of a stroke), damage to the vestibular system can result. Rarely, a slow-growing tumor on the nerve that leads from the inner ear to the brain (an acoustic neuroma) may interfere with the normal function of the vestibular system. Finally, the causes of some vestibular disorders remain a mystery. How Are Vestibular Disorders Diagnosed? Tests developed since 1984 enable physicians to diagnose some vestibular disorders that previously could not be documented. Modern diagnostic techniques for vestibular disorders rely on a combination of tests and a careful history of the problem. First, a complete physical examination to rule out other causes of dizziness such as cardiovascular or central nervous system disorders must be done. Then, the patient will be referred to a specialist (an otolaryngologist or neuro- otologist) for vestibular testing. Because the vestibular system is in close proximity to the hearing apparatus, vestibular testing includes hearing tests. Eye movements often hold clues to vestibular dysfunction. To record eye movements, physicians use a technique called electronystagmography (ENG). In ENG testing, electrodes are put on the facial muscles that control eye movement. The patient is then placed in a variety of situations, and the eye movements are electronically recorded. Balance is an essential component of vestibular functioning. During balance testing, patients may be asked to stand on special platforms that record the movement of the body. This kind of testing is called moving platform posturography. How Are Vestibular Disorders Treated? Treatment for vestibular disorders varies according to the diagnosis. What works in one case could make matters worse in another. In mild cases, the symptoms may go away on their own as the vestibular apparatus heals or the nervous system learns to compensate for the disorder. Where symptoms persist, some patients can be cured completely. In other persistent cases, the symptoms can only be controlled and not eliminated entirely. Treatments may consist of drugs, diets, physical therapy, or in severe cases, surgery. What If I'm Disabled? Although most vestibular disorders are treatable, some people with the disorders find they are temporarily or permanently unable to work or carry on normal activities. Social Security disability as well as many employee disability plans cover chronic, severe disability caused by vestibular disorders. Such disability payments can be received only if physicians attest to the disabling effects of the disorder. Records of medical exams and physician visits will help in determining the existence of a disability. Patients will often be asked to see specific physicians for examinations. Persistence and attentiveness to fulfilling all the official requirements is important. It is often useful to have a care giver, social worker, or friend help with the record-keeping and paperwork. Where Can People with Vestibular Disorders Get Help? Anyone troubled by symptoms of dizziness or imbalance should see his or her regular doctor first. If vestibular disorders are suspected, the family physician or the Vestibular Disorders Association can recommend physicians who specialize in diseases of the inner ear and who can perform the necessary tests. Vestibular disorders can be as mild as the momentary imbalance you feel when you get off a whirling carnival ride. However, they can also be disruptive and debilitating. If you or someone you know is suffering from a vestibular disorder, you can find help. The Vestibular Disorders Association is dedicated to helping you find knowledgeable physicians, to distributing information about these disorders, and to providing videotapes, booklets, a quarterly newsletter, and other materials to enable you to cope with your symptoms. This document is not intended as a substitute for professional health care.