DIZZINESS

Dizziness is a common medical problem. Thirty percent of people over age sixty-five complain of dizziness and 20 percent of all older persons experience dizziness severe enough to seek medical advice.

The syndrome of dizziness is varied and encompasses a wide range of symptoms. Getting a precise and accurate description of the individual's symptoms is therefore essential for making an accurate diagnosis and helps to differentiate between the four medical subtypes traditionally considered to be the most common causes of dizziness: vertigo, presyncope, dysequilibrium, and light-headedness.

Causes of dizziness

Vertigo is the illusion of movement of either the body or environment. This symptom is often described using terms such as spinning, turning, reeling, or any other depiction of movement. Most commonly, vertigo is due to a problem within the inner ear or the vestibular nerve, which is the nerve that helps to maintain balance. Benign positional vertigo, an illness caused by free-floating particles within the inner ear, can be diagnosed by its characteristic symptoms. With this illness, vertigo is provoked by changing position or moving the head, and symptoms usually last thirty seconds to several minutes. On the other hand, vestibular neuronitis, also called acute labyrinthitis or vestibulitis, usually causes a single episode of vertigo that may last from one day to several months. Vestibular neuronitis is thought to be caused by a viral infection. Another illness of the inner ear, Meniere's disease, can be differentiated by its long duration and associated hearing loss. Sometimes, vertigo can be caused by a central problem within the brain, such as a stroke.

The term presyncope refers to near fainting. People describe this as "blacking out" or "nearly fainting." There are many causes of presyncope, such as abnormal heart rhythms, medication, problems with internal blood pressure control (carotid hypersensitivity), and volume depletion. Not uncommonly, presyncope will occur without an identifiable underlying medical illness or specific cause.

The two remaining subtypes of dizziness, dysequilibrium and light-headedness, are less specific and in many cases the cause of these complaints cannot be accurately determined. The term dysequilibrium refers to a feeling of imbalance. The subtype of light-headedness is reserved for symptoms of dizziness that do not fit into any of the three other categories.

Although these subtypes of dizziness account for some causes of dizziness, it is not always possible to classify symptoms in a given individual. Often, one simple cause cannot be found to explain why dizziness is occurring and frequently there are several contributing causes, none of which alone would pose a problem. In combination, however, these factors produce the sensation of dizziness. Common contributors to dizziness include medication, impaired balance, heart disease, visual impairment, hearing loss, blood pressure that drops upon standing (i.e., orthostatic hypotension), decreased sensation in the feet, and chronic medical problems. Other cited causes of dizziness include psychiatric problems, hyperventilation, seizures, and disorders of the neck.

Evaluation

The tests needed to evaluate dizziness will depend on the information gathered during the clinical interview. Confirmation of the clinical diagnosis through physical examination and laboratory testing is necessary. In order to document whether there is a fall in blood pressure as the person stands up, examination should include blood pressure measurement in the lying and standing positions. Checking for vestibular abnormalities, examining vision, observing gait, and looking for neurologic abnormalities can be helpful. Important laboratory tests include measures of blood cell counts, thyroid function, blood chemistry (such as sodium), kidney function, calcium, and liver function. Sometimes additional tests may be needed to clarify the diagnosis. These could include tests of hearing and vestibular function, monitoring heart rhythm, evaluation of hearing, or CT or MRI scanning of the head.

Treatment

Management of dizziness will depend upon the subtype and causes identified. Antivertigo medications, such antihistamines and others, can be used to treat the debilitating symptoms of vestibular neuronitis, such as nausea, vomiting, and the sensation of movement. These treatments should be used for short periods of time and withdrawn as soon as symptoms improve. Side effects of these medications include stomach upset, fatigue, and confusion. For benign positional vertigo, there is evidence that antivertigo medications may delay improvement. In this circumstance, vestibular desensitization, such as rapidly tilting the body from one side to the other, may alleviate symptoms. Meniere's disease is treated with salt restriction, diuretic therapy, surgery, or antivertigo medications. Most of these treatments have uncertain benefits and are generally recommended only for short-term use. Aspirin, or another medication with antiplatelet effect, is recommended for stroke-related vertigo.

Treatment of dizziness caused by presyncope involves identifying whether or not there is an underlying cause. Presyncope may be caused by medications that lower blood pressure or cause dehydration (diuretics), or by medical illnesses, such as blood loss or arrhythmias. In these cases the identified problem should be appropriately treated. Information about treating presyncope that is associated with a drop in blood pressure when standing can be found in the section on fainting.

In many instances, a single cause of dizziness will not explain the symptoms and the focus of treatment will involve correcting as many contributing problems as possible. Offending medications should be stopped, gradually decreased, or replaced. Correcting vision and optimizing health status may be helpful. Exercise and walking aids may ameliorate problems of balance.

Conclusion

Dizziness is a common and challenging problem for an elderly person, which requires a systematic and detailed approach. Once medical problems are identified, treatment requires careful management of each difficulty identified, with fastidious follow-up to determine whether treatment is effective or producing side effects. In some circumstances, dizziness will not respond to treatment, in which case supportive therapy will be necessary.

LAURIE HERZIG MALLERY

See also BALANCE AND MOBILITY; FAINTING; HEARING.

BIBLIOGRAPHY

COLLEDGE, N. R.; WILSON, J. A.; MACINTYRE, C. C. A.; and MACLENNAN, W. J. "The Prevalence and Characteristics of Dizziness in an Elderly Community." Age and Ageing 23 (1994): 117–120.

FURMAN, J. M., and CASS, S. P. "Benign Paroxysmal Positional Vertigo." The New England Journal of Medicine 341, no. 21 (1999): 1590–1596.

SLOANE, PHILIP; BLAZER, DAN; and GEORGE, LINDAK. "Dizziness in a Community Elderly Population." Journal of the American Geriatric Society 37 (1989): 101–108.