Autoimmune Inner Ear Disease (AIED)

 

by Neil Bauman, Ph.D.

 

Question: There seems to be a lot of talk about autoimmune inner ear disease now. What exactly is this? How do I know if this caused my hearing loss? What can I do about it?—P. R.

Answer: Good questions! Autoimmune Inner Ear Disease (AIED) is one of those mystery conditions that bedevil and baffle so many doctors. Even today, not much is definitely understood about AIED. It is still the subject of much controversy and debate. The good news is that researchers are busy learning more about AIED so they can find effective ways of preventing and/or treating it.

What is AIED?

The short answer is, “Autoimmune inner ear disease (AIED) results when your body’s out-of-control immune system attacks your inner ear tissues.”

God designed your extremely complex immune system to ward off infections. Normally your immune system fights invaders such as bacteria, viruses and cells from other organisms. However, sometimes something goes wrong and the antibodies and immune cells in your immune system fail to distinguish the “bad guys” from the “good guys.” As a result, your immune system attacks various cells in your body. This results in one of the more than 80 identified autoimmune diseases. If this attack takes place in your inner ears, you end up with AIED.

AIED consists of a syndrome that may include sudden or progressive hearing loss in both ears, tinnitus, dizziness and a feeling of fullness in your ears.

Characteristics of AIED

Here are some things we now know about AIED.

1. The hearing loss is sensorineural (the old term was “nerve deafness”) and normally occurs in both ears (79%) at the same time. The actual hearing loss often is somewhat different in each ear however (asymmetric).

2. When AIED only occurs in one ear, generally it will show up in your other ear at a later date.

3. When AIED occurs, your hearing loss progresses rapidly and gets steadily worse over a period of weeks or months and even up to a year or more. In contrast, Sudden Sensorineural Hearing Loss (SSHL) occurs over a matter of minutes to hours to days.

4. While you are losing your hearing, your hearing may fluctuate (so you may have “good days” and “bad days”), then stabilize at a certain level, or it may continue to get worse without any fluctuation.

5. AIED generally impairs your ability to understand speech. This may even be a bigger problem than the resulting hearing loss. If you have AIED, your speech discrimination test scores will often be poor.

6. About 50% of the people with AIED have balance (vestibular) problems. These symptoms can include vertigo (a spinning sensation), dizziness, imbalance (disequilibrium), ataxia (staggering gait) and motion intolerance.

7. Between 25% and 50% of the people with AIED have tinnitus (ringing, roaring, hissing, etc. in their ears) and/or a feeling of fullness in their ears.

8. Meniere’s disease and AIED seem to be closely intertwined. In fact, immune dysfunction is increasingly being recognized as one of the factors that causes Meniere’s disease. Researchers now feel that a “significant percentage” of the people with bilateral Meniere’s disease have AIED as the underlying cause. One study indicated that immune system dysfunction was responsible for 16% of people with bilateral Meniere’s disease and 6% of all people with any variety of Meniere’s disease. In another study, 96% of the patients with Meniere’s disease had elevated levels of circulating immune complexes, compared to just 20% of the controls. In yet another study, specific immune system antibodies were detected in 47% of people with Meniere’s disease. This all shows that a large percentage of the people with Meniere’s disease have an underlying immune system problem.

9. AIED generally does not occur alone, but often appears at the same time as other autoimmune diseases.

10. More women than men have AIED. This is not surprising for two reasons. First, 75% of all autoimmune diseases occur in women. This is likely related to hormones. Second, since AIED often occurs in conjunction with other autoimmune diseases, it follows logically that more women than men would develop AIED. Researchers have observed that 65% of the AIED cases reported occur in women between the ages of 17 and 42.

Risk Factors for Getting AIED

There are several factors that increase your chances of getting AIED. Those already identified include:

Another Autoimmune Disease

The main risk factor for developing AIED is already having an autoimmune disease in another part of your body. Autoimmune diseases such as Addison’s disease, ankylosing spondylitis, Cogan’s disease, dermatomyositis, Graves’ disease, Guillain-Barre syndrome, Hashimoto’s thyroiditis, insulin-dependent (Type 1) diabetes mellitus, pernicious anemia, polyarteritis nodosa, psoriasis, rheumatoid arthritis, sarcoidosis, scleroderma, Sjoegren’s syndrome (dry eye syndrome), systemic lupus erythematosus (SLE), ulcerative colitis, and Wegener’s granulomatosis can cause or be associated with AIED.

Allergies

It seems that allergies can cause or at least are associated with AIED. Exactly how these “fit” together is still unknown. However, a large percentage of the people treated with immunotherapy for inhalant allergies showed improvement in vertigo and other Meniere’s symptoms, suggesting an association between Immunoglobulin E (IgE) disease and inner ear problems.

Here is one man’s experience with AIED and allergies. He explained, “After undergoing steroids and all sorts of medical treatment with no results, I finally heard about allergies being a cause of AIED. After being tested, I found I have terrible environmental and food allergies. Allergy shots have really helped and I am improving now. I also found that in my case, MSG (monosodium glutamate) and various food additives cause attacks of hearing loss and tinnitus. These substances can cause immune system dysfunction. The longer I stay away from such things, the better I feel. Your body doesn’t turn on itself for no good reason—it has a little help! Please pass this information along to other people who suffer this horrible agony.”

Genetic Factors

Observation suggests there is a genetic component as autoimmune diseases seem to cluster in families. Research indicates that the ability to develop an autoimmune disease is determined by a dominant genetic trait that is very common (20% of the population). Interestingly, this trait may show up as several different autoimmune diseases within the same family. However, this genetic predisposition alone does not cause autoimmune diseases to develop. Other factors need to be present as well in order to initiate the disease process.

Evidence suggests that factors such as bacteria, viruses, toxins and some drugs may play a role in triggering an autoimmune response in someone who already has a genetic (inherited) predisposition to autoimmune reactions. Researchers think that the inflammation initiated by these agents, whether toxic or infectious, somehow provokes in the body a “sensitization” (autoimmune reaction) to the involved tissues.

Genetically-controlled aspects of the immune system may be associated with increased susceptibility to hearing disorders such as Meniere’s disease. For example, in one study, 44% of patients with Meniere’s had one particular genetic trait as compared to only 7% of the controls. This suggests that more Meniere’s disease may be caused by immune dysfunction than is presently generally thought.

How Common is AIED?

Autoimmune diseases of all kinds strike an estimated 14 to 50 million people in the US. Many people who ultimately get AIED come from this enormous “pool” of people with existing autoimmune diseases.

At present, no one seems to have a clue just how many people actually have AIED since researchers are still trying to refine and identify this disease. Furthermore, mild versions of AIED are probably never even reported.

The figure that is currently bandied about is that less than 1% of hard of hearing people have AIED. This figure seems much too low since approximately half of the people with Meniere’s disease are thought to have AIED as the underlying cause. Meniere’s disease affects approximately 6% of hard of hearing people. Therefore, the incidence of AIED from Meniere’s sufferers alone would be about 3%.

Diagnosing AIED

Diagnosing AIED is a tricky business. This is because there is still no well-established means of diagnosing AIED although researchers are working on it. Doctors try to diagnose AIED based on medical history, findings of physical examination, blood tests, and the results of hearing and balance tests. Dr. Timothy Hain declares, “While specific tests for autoimmunity to the inner ear would be desirable, as of this writing, [Sep 2001], there are none that are commercially available and proven to be useful.” As a result, doctors often look for evidence of other autoimmune diseases that may be present elsewhere in the body to indicate that AIED might also be present.

One of the chief ways doctors confirm their diagnosis of AIED is to try a course of immunosuppressant drugs. Researchers have found that if you have certain anti-bodies in your blood, you will very likely respond positively to steroid treatment. Therefore, if the patient responds positively, doctors assume this confirms their diagnosis that it must have been AIED!

Treating AIED

The treatment goal in people severely affected with AIED is to improve their hearing/discrimination enough so that they can benefit from wearing hearing aids. In those with mild to moderate losses, the goal is to recover hearing to normal or near normal levels.

Doctors think that AIED is potentially reversible. Therefore they like to treat it with steroid drugs and see if they can stop the progress of AIED or make it retreat since steroids are the drug of choice for other autoimmune diseases. Sometimes it seems to work. Sometimes it doesn’t do a thing. In fact, doctors don’t have a clue what would happen if no treatment was given since, when patients come to them, they always “try” something. Dr. Shelley Broughton wrote, “The natural history of untreated immune-mediated inner ear disease is unknown at this time.” In other words, doctors don’t know what would happen if they kept their hands off and let nature take its course.

Because many doctors believe that AIED is caused by inflammation and altered immunity, they try the same immunosuppressive drugs they use to treat rheumatoid arthritis and cancer. According to the American Academy of Otolaryngology—Head and Neck Surgery, Inc., they use high doses Prednisone, Methotrexate, and Cyclophosphamide, but with “little guidance about dosages or duration of treatment and with less than ideal proof of efficacy.”

Reading between the lines, you can see that doctors at present don’t know how much of which drugs to prescribe. They don’t know how long they should prescribe these drugs. Finally, they don’t have a clue whether these drugs work or not! As a result, you need to decide for yourself if you want to risk all the harmful side effects to your body from these dangerous drugs on the chance that it will help your hearing. They may, and then again, they may not.

If you are going to go the drug treatment route, you need to begin promptly. This is extremely important to have the best chance to recover or at least stop the hearing loss. However, aggressive treatment doesn’t necessarily work. In spite of the best treatment from the best doctors, you may still lose your hearing.

Not all people respond to steroid therapy the same way. Treatment in some people results in better hearing, or better discrimination or both. With others, hearing fluctuation or hearing loss progression stabilizes where it is without improving any. With the remainder, they continue to lose their hearing in spite of immunosuppressive therapy.

In cases of rapidly progressing bilateral hearing loss, doctors try steroids such as Prednisone (Deltasone) or Dexamethasone (Decadron) for 4 weeks. If the person responds to this treatment, then they often put them on long-term chemotherapy drugs such as Cyclophosphamide (Cytoxan), Methotrexate (Rheumatrex), or Azathioprine (Imuran).

In one study using Methotrexate, the patients had significant improvement in their discrimination scores, but did not have any improvement in their hearing.

Overall, steroid response rates are approximately 60%. Success is defined as a hearing improvement of just 10-15 dB, or a “significant” improvement in discrimination scores. For a severe loss, this is not all that great an improvement, but at least the hearing loss isn’t progressing any more!

Plasmapheresis treatment may also be beneficial. This involves filtering the patient’s blood, which removes antibody, antigen, and immune complexes and other immune mediators. 75% of the patients in one study regained some of their hearing after this treatment.

The anti-TNF drug, Etanercept (Enbrel) shows promise too.

Prednisone, although an effective immunosuppressant drug, has a host of negative side effects, especially in the long term. You want to be aware of them. You need to know that you can get both cataracts and glaucoma (among other things) from taking Prednisone. If the Prednisone treatment isn’t successful in restoring your hearing, you could find yourself up a creek without a paddle, ending up both hard of hearing and without much sight.

You also want to be careful when taking any cytotoxic drugs because their side effects can also be serious. For example, Cyclophosphamide is often prescribed, yet it can cause increased risk of malignancy (cancer).

Caution: None of the above drugs are meant for long-term use—unless you like horrible side effects messing up your body. One person who had that experience warns, “If steroids don’t regain or stop your hearing loss, get off them after just a few weeks.” (I’d suggest that if there is no change within 4 weeks, these drugs are unlikely to help you and you should dump them before their side effects totally mess up your body.) Also, if you have had a sudden hearing loss for more than a month or two already, don’t expect the steroids to really do much to help you regain your hearing. By that time, the chances of getting your hearing back are minimal, so why risk all the nasty side effects with so little chance of success?

If you have (or think you have) AIED, talk with your doctor—preferably an otologist (or neurotologist). Together decide on a course of treatment (if any) that fits your particular situation and takes into consideration the risks that are acceptable to you.