Apr. 22, 2001 at 20:21 CDT
By Connie Lauerman
CHICAGO -- Most of us have experienced momentary dizziness after a lurching train ride or a spin on a carousel or when looking down from a high floor of a skyscraper. But dizziness also can be a signal of something ominous or a problem that interferes with daily living.
Only lower back pain and headaches exceed dizziness as more common complaints that patients report to doctors.
It's arguably one of the most complicated symptoms in medicine because its possible causes are myriad, and a diagnostic misstep could have serious consequences.
Dizziness can be a symptom of an inner ear problem, a side effect of medication, part of a psychiatric disorder or a cardiac problem, as well as the calling card of a brain tumor or seizure.
What's more, dizziness is a subjective complaint and often is difficult to describe. It may manifest itself as a feeling of being about to faint or lose balance, a sensation of spinning (vertigo) or a wave of unsettling lightheadedness.
In an initial examination, an internist or family practitioner may try to find a straightforward cause, such as dehydration, diet, low blood pressure, a reaction to a medication or a severe allergic response. Then a patient with dizziness may be referred to an otolaryngologist (ear, nose and throat specialist), a neurologist or both for further evaluation.
"Dizziness is very challenging [to diagnose]," said Dr. Sam Marzo, an assistant professor of otolaryngology and director of the Balance Center at Loyola University Medical Center. "Thirty percent of the population experiences dizziness by age 65, so as the population ages we expect dizziness to be more and more common."
One of the most common causes of dizziness is a disturbance in the vestibular system that helps people maintain balance.
"The way the balance system is wired, you have eyes, ears, fingers and toes that are all sensors sending information to the brain, which puts it all together and then directs commands to the muscles and nerves," Marzo said.
"You can have a problem in any one of those areas."
The vestibular system is a delicate structure in the inner ear that includes semicircular canals and the cochlea, where membranes sense sound.
A viral inner-ear infection can affect the balance canals, resulting in dizziness, nausea and even vomiting, according to Marzo. Involvement of the cochlea may be signaled by ringing in the ear, a feeling of fullness or even hearing loss.
Such inner-ear infections sometimes develop after a cold or upper respiratory infection and may take weeks to subside.
If vertigo is the main symptom and occurs after sudden movements such as rolling over in bed, the cause likely would be benign positional paroxysmal vertigo (BPPV). Doctors believe the condition is caused when microscopic crystals break loose from the bottom of the inner ear, where they normally help us sense balance, and float in the balance canals.
A simple test called the Epley maneuver diagnoses and relieves BPPV. This treatment involves rotating the patient into various positions that help return the particles to the bottom of the inner ear. Severe cases may require medication and one or more treatment sessions.
A less common diagnosis is Meniere's disease, an imbalance of fluid in the inner ear usually resulting in recurrent attacks of dizziness, ringing in the ear, hearing loss and, for some patients, migraine headaches.
In most cases, it can be controlled through diet and taking a diuretic, though some patients require surgery.
A study presented at the American Academy of Neurology's annual meeting last spring underscored the need to consider inner ear problems as the cause of sudden falls experienced by older patients, especially when their vertigo or falling spells are not accompanied by the symptoms usually associated with the ear.
Led by Dr. Gail Ishiyma, a neurologist at the UCLA School of Medicine, the study included five men and three women who had had attacks of suddenly falling down that began after age 55. Prior to the study, one patient had been put on long-term seizure medications despite three negative seizure tests, and another patient was fitted with a cardiac pacemaker that did not help resolve the problem.
After thorough diagnostic workups, three of the patients were found to have Meniere's disease, and the five others had delayed endolymphatic hydrops. That's a disorder similar to Meniere's, but its symptoms -- dizziness and falls -- may occur years after hearing loss.
Dizziness can also be a symptom of multiple sclerosis, a disabling neurological disease or a brain tumor.
"It's important to distinguish between lightheadedness and dizziness," said Dr. Leonard Cerullo, chairman of neurosurgery at Rush University Medical School.
"A lot of people become lightheaded, for instance, if they get up too fast and [that's] usually associated with some sort of heart problem or blood pressure problem.
"The types of dizziness that are associated with brain problems usually involve real vertigo, which by definition means the room is spinning. And it's positional, so that if you hold your head in one position it happens and if you hold your head in a different position it doesn't happen."
When vertigo is associated with other symptoms such as hearing loss or ringing in the ear, Cerullo said, a vascular problem or a tumor has to be ruled out.
"The typical tumor would be an acoustic neuroma, and the typical vascular problem would be some sort of abnormal communication between an artery and a vein," he said.
"Very frequently, tumors will announce themselves with dizziness. Sometimes what's perceived as dizziness is not really dizziness at all but a minor seizure, and that, of course, is a major calling card of tumors."
Patients rarely go to psychiatrists reporting dizziness, but it's one of a cluster of symptoms associated with panic disorder.
"The part of the brain that controls `fight or flight' just starts firing at a very high rate," said Dr. Emil Coccaro, chief of adult psychiatry at the University of Chicago. "[People] get woozy. They start breathing hard. Their heart pounds. They get tremulous."
A review of 30 years of articles on a medical database that addressed dizziness or vertigo, analyzed by Dr. Kurt Kroenkeof of the Regenstrief Institute for Health Care in Indianapolis and associates, revealed that dizziness was due to vestibular disorders or psychiatric causes in more than 70 percent of the cases.
The review, published in the Southern Medical Journal last year, also showed that the most serious causes, cerebrovascular disease, cardiac arrhythmia and brain tumors, were the least common. But in 13 percent of the cases, the cause of dizziness was unknown.