There are many causes of dizziness. Although it usually comes from benign problems of the inner ear, if you've experienced it, you know how disabling and frustrating it can be.

Because balance is affected by so many different factors, trying to diagnose the cause of vertigo can be almost as frustrating as the disease. Nonetheless, we make the effort to find the cause in each case because a specific diagnosis helps determine the best therapy.

Our sense of balance comes from the vestibular system which takes information from the inner ears, eyes and muscles and sends it all to the brain's balance center. Although most causes of dizziness are benign and self-limited, testing is usually needed to help assure there are not other more concerning causes such as tumors or strokes. Dizziness can be a difficult feeling to describe.

We usually think of three major types: vertigo, lightheadedness and imbalance.

Vertigo is a definite spinning sensation and almost always points to the inner ear.

Anatomy and Physiology

There are two parts of hearing: mechanical and nerve or electrical. The mechanical part picks up sound from the outer ear canal and then vibrates the ear drum and three tiny hearing bones in the middle ear.

The inner ear looks a bit like a snail. It has two halves which are connected and are filled with fluid.

The coil or cochlea takes care of the nerve-part of hearing. Like a telephone, it takes the vibration and turns it into an electric signal that is relayed to the brain.

The other half of the inner ear is the balance or vestibular system. There are three balance canals, each set in a different direction. Depending on which way you turn, fluid moves within the canals and sends the direction to the brain by way of the vestibular nerve.

Inner ear fluid undergoes a natural recycling everyday. It is made from the brain's spinal fluid and is absorbed by the endolymphatic sac. In Meniere's disease, the sac fails to absorb enough fluid. This increases inner ear pressure resulting in dizziness and hearing loss.

Also in close association to the ear is the facial nerve. It helps move the face and also provides for some of the taste fibers to the tip of the tongue.

Treatment

There are different types of medical treatment. During an acute spell, suppressant medications such as antivert or valium can provide symptomatic relief. These drugs, however, do nothing to cure the problem. But, like treating sea-sickness, getting symptomatic relief and waiting for the spell to pass is all that may be needed. Remember that all of these suppressants can cause drowsiness. Thus, you must be extemely careful with driving and other risky activities because the combination of dizziness with drowsiness can be hazardous.

Some causes of dizziness may allow the physician to be more specific in treating the disease rather than the symptoms. Meniere's Disease is a good example. Because the attacks come from too much fluid pressure within the inner ear, a water pill can sometimes be very helpful. Steroids may be used for severe cases.

Diet and lifestyle changes can be important since many causes of dizziness are due to fluid retention or circulation problems. Patients with Meniere's disease often improve if they avoid salt, caffiene, nicotine and fatty foods.

Finally, some patients who have a particularly stubborn type of dizziness such as the unsteadiness that occurs following a stroke, may require physical therapy in order to see some improvement.

When medical therapy or time alone fail to relieve dizziness, surgery can be considered if the cause is found to be within one of the inner ears.

Diseases and their Surgical Treatment

Benign Positional Vertigo is a common form of dizziness that occurs following viral infection or head injury. Tiny sand-like particles may form in a sensitive part of the inner ear. Sometimes, this can be treated by rotating a patient's head in a particular fashion in order to try and get the particles to float into a less sensitive part of the inner ear. This is called Particle Repositioning. Patients are asked not to lie flat for two days to give the particles a better chance of sticking in their new location. Sometimes this needs to be repeated on a few occasions. If symptoms persist, surgery can be considered in which the hypersensitive part of the inner ear is blocked off.

This called Posterior Canal Occlusion surgery. The offending canal is exposed after opening the mastoid cavity. The inner ear lining is shrunk using a laser and then the canal is filled with tissue.

Vestibular neuritis is the medical term for dizziness caused by a virus.

Viruses probably cause most inner ear attacks but fortunately these usually resolve on their own. In some cases, however, the dizziness may persist and be disabling. If medical therapy or tincture of time are not effective, the balance nerve can be clipped between the inner ear and the brain to stop false information coming from the diseased ear. This operation is called a vestibular nerve section and is a major procedure. The nerve clipping operation is delicate procedure which attempts to give a good chance of removing the faulty balance function of the ear while preserving the hearing half. Occasionally, the virus may also cause deafness in which case a more minor surgery called a labyrinthectomy can be performed in which the lining of the inner ear can be completely removed because there is no need to preserve the hearing part of the ear.

Meniere's Disease is another common cause of dizziness which is associated with hearing loss, ringing of the ears (tinnitus) and ear pressure. If it does not improve with diet and a water pill, there are three operations that can be considered. If the disease has created a permanent deafness then a labyrinthectomy is be performed because there is no need to preserve the hearing part of the ear.

If useful hearing remains, then there is a choice between the nerve clipping operation (vestibular nerve section) or an endolymphatic sac decompression.

The sac operation is a more minor procedure the goal of which is to relieve pressure within the inner ear rather than removing the balance function as cutting the nerve does. Although it is not as effective as vestibular nerve section, it avoids many potential risks because it is not necessary to work within the brain's cavity.

Trying to decide between these two operations is a common problem. The nerve clipping operation is one of the most successful treatments for Meniere's disease but there are surgical risks related to working along the nerve's root at the brainstem. Also, after cutting one balance nerve, it takes awhile for the other ear to take over. Head exercises are important to help overcome unsteadiness.

The following table may be helpful in deciding which operation is best.

Efficacy Risks Hospitalization Recovery Nerve Section 95% Moderate 7 days 1 - 2 months Sac Decompression 80% Low 2 days 1 - 2 weeks

Other deciding factors include the patients hearing, age, health and the severity of disease.

Unfortunately, Meniere's disease can sometimes affect not one but both ears.

In that case, we are reluctant to cut either balance nerve so a sac decompression is preferred. Another alternative is to give streptomycin or gentamycin. These are strong medications that were first used as antibiotics.

It was eventually discovered to have an unusual side effect wherein high doses could destroy balance function. Research is currently attempting to find ways to give this medication in small controlled doses with the goal of reducing dizziness while preserving balance and hearing.

Perilymph Fistula

Some patients develop a small leak of fluid from the inner ear. Such a so-called "perilymph fistula" can occur after scuba diving, air flight, hard nose blowing or head injury. There are no tests that can reliably diagnose this problem. If your doctor suspects this, a brief exploration of the inner ear as an outpatient under a local anesthetic may be recommended. If a leak is found, it can be patched with a small amount of tissue taken from behind your ear.

Deciding on a therapy

If you are unfortunate enough to have one of the types of dizziness that does not resolve on its own, you and your doctor will need to decide on which therapy is best for you. This is always a matter of weighing the pro's and con's of each option whether it is medical or surgical.

If you use medications to treat your dizziness, be careful about side-effects including drowsiness with Antivert or low potassium with water pills.

Steroids, of course, have many side-effects. Make sure to discuss them with your doctor.

Surgical risks vary according to the procedure and by a person's age and health. Most inner ear operations require a general anesthetic and an incision behind the ear after shaving a small amount of hair. Any surgery in or around the ear can put at risk many of the structures that reside in this area.

Therefore, risks typically include hearing loss, tinnitus, dizziness, infection and bleeding. Because of the close relationship of the facial nerve, face weakness or taste distubances are possible.

Surgery performed adjacent to the brain adds additional risks to life, brain and the surrounding nerves. In order to prevent a leakage of spinal fluid, patients who undergo clipping of the balance nerve often have a small amount of belly fat taken as a graft to seal the area underneath the incision.

Make sure and ask your doctor how soon you may return to work or driving after surgery. This will vary based on the severity of your dizziness and the type of surgery. It may range from days to many weeks. Stuffiness and hearing loss can be expected for some time with any ear operation. This will usually improve slowly as your body absorbs the healing fluids.

Fortunately, most types of dizziness can be cured or at least improved. But in some cases, no medical or surgical treatment may be effective. If so, patients will need to learn how to adapt to a chronic problem. Diet, rehabilitation and exercise can all be important as can developing a positive attitude.