Section 6. Brain, Spinal Cord, and Nerve Disorders

Chapter 80. Dizziness and Vertigo

Topics: Introduction | Vertigo | Motion Sickness | Benign Paroxysmal Positional Vertigo

Introduction

Dizziness is a vague term used to describe various sensations, including faintness, light-headedness, a loss of balance, a sense of spinning, a vague spaced-out feeling, and weakness. Vertigo is a specific sensation in which the person or the person's surroundings seem to be moving or spinning.

Doctors usually classify dizziness as faintness or light-headedness, in which the person feels about to lose consciousness; loss of balance, in which the person feels unsteady and about to fall; vertigo; a mixture of these types; or none of these types. Dizziness may be temporary or chronic. Chronic dizziness is more common among older people.

Dizziness accounts for about 5 to 6% of visits to the doctor. It may occur at any age but becomes more common as people age. It affects about 40% of people older than 40 at some time.

Although dizziness may be disturbing and even incapacitating, only about 5% of cases result from a serious disorder. Each type of dizziness tends to have characteristic causes. For example, faintness and light-headedness may result from a sudden fall in blood pressure (see Section 3, Chapter 23) or other disorders that result in an inadequate blood supply to the brain. Such disorders include coronary artery disease, abnormal heart rhythms, and heart failure. Anxiety disorders and abnormally rapid breathing (hyperventilation) may also cause light-headedness.

Loss of balance may result from vision disorders, especially double vision, because the body depends on visual cues to maintain balance. Loss of balance may also result from musculoskeletal disorders, which cause muscle weakness and thus interfere with walking; use of certain drugs, such as anticonvulsants and sedatives; or disorders of the inner ear, which can also cause vertigo. Vertigo has many causes, including motion sickness, benign paroxysmal positional vertigo (see Section 6, Chapter 80), and Meniere's disease (see Section 19, Chapter 220). Chronic dizziness, especially in older people, may result from several disorders.

At any age, dizziness can cause problems, particularly when performing an exacting or a dangerous task. In older people, chronic dizziness increases the risk of falling and fractures and decreases the ability to perform daily activities.

Diagnosis and Treatment

People who have dizziness that persists or interferes with daily activities should see a doctor.

Before dizziness can be treated, doctors must determine its nature and its cause. Doctors ask the person to describe in detail the sensations felt: whether the feeling during the episode was faintness, light-headedness, loss of balance, spinning or movement of self or the surroundings (vertigo), or another sensation. The person is asked when the dizziness began, how long it lasted, what triggered or relieved it, and what other symptoms--headaches, deafness, noise in the ears (tinnitus), impaired vision, weakness, or difficulty walking--were present. Such details help pinpoint the nature of the dizziness.

Balance is tested by asking the person to stand still and then to walk a straight line, first with the eyes open, then with the eyes closed. Vision tests are performed, and the eyes may be checked for abnormal movements (such as nystagmus (see Section 6, Chapter 80)). Hearing tests are performed, because they can often detect inner ear disorders that affect both balance and hearing.

To determine whether the cause of the dizziness is a sudden fall in blood pressure, doctors measure blood pressure and pulse when the person is sitting or lying down, then after the person stands. Electrocardiography, echocardiography, and exercise stress testing may also be performed to evaluate heart function.

Additional diagnostic procedures may include computed tomography (CT) or magnetic resonance imaging (MRI) of the head and a spinal tap (lumbar puncture). If doctors suspect that the blood supply to the brain is inadequate, angiography, magnetic resonance angiography (MRA), or Doppler ultrasonography of the head may be performed. These procedures can show whether arteries to the brain are narrowed or blocked. Because MRA is not invasive, MRA with ultrasonography is generally preferred to angiography, which involves insertion of a catheter into an artery.

When no cause is identified, doctors can reassure the person that no serious disorder has been identified. When a cause is identified or suspected, treatment varies, depending on the cause. For example, if the cause is a drug, the drug is discontinued or the dose reduced. Drugs may be given to relieve accompanying symptoms (such as nausea) or to prevent blood pressure from falling. Anticoagulants may be given to prevent clot formation and stroke. Rarely, surgery is performed--for example, to remove a tumor. Benign paroxysmal positional vertigo can be relieved by a simple maneuver (Epley maneuver) performed in the doctor's office.