Although steroids are effective for many patients with autoimmune inner ear disease (AIED), there are still challenges in diagnosing the condition, mysteries behind what happens to the inner ear, and controversy over whether intratympanic injections help.
Explore this issue:December 2007
AIED is a rapidly-progressive bilateral sensorineural hearing loss. Usually, hearing loss occurs in one ear first, then progresses to the second ear. It is often not caught until there is a decline in hearing in the second ear. The condition tends to be steroid-responsive, but there are some controversies and uncertainties in their use for some types of AIED.
ENToday spoke to two thought leaders in the field: Jeffrey Harris, MD, PhD, Professor and Chief of Otolaryngology at the University of California, San Diego, and Steven Rauch, MD, Associate Professor of Otology and Laryngology at Harvard Medical School. Both agreed that, generally, steroids are effective for AIED, but because of side effects with long-term use there is a limit to their use. Steroids have a number of actions believed to help AIED and its various causes. They have anti-inflammatory action, are immunosuppressive, and can target glucocortcicoid receptors in the inner ear.
We don’t really know which of those effects are most prevalent in autoimmune treatment, Dr. Harris said.
AIED Classification System
Dr. Harris has developed a classification system for AIED and AIED-like conditions that breaks the condition into six key categories.
The first is rapidly progressive bilateral sensorineural hearing loss where there is no evident systemic autoimmune disease. This can occur in people of any age, but only about 50% of these patients respond to high-dose steroids.
The second form of AIED usually occurs with a flare-up of an existing autoimmune condition, such as lupus, ulcerative colitis, or rheumatoid arthritis. Serological studies will confirm the illness. We usually maintain these patients with drugs that are effective for their rheumatic condition as well-so we start with high-dose steroids but we convert them to other drugs that manage their rheumatic diseases, Dr. Harris said.
Third is an immune-mediated Méniàre’s disease, which consists of bilateral, fluctuating sensorineural hearing loss. Vertigo may predominate as a symptom. The condition is steroid-responsive, but may require long-term immunosuppression.
A fourth type is rapidly progressive bilateral sensorineual hearing loss that accompanies inflammatory disease such as chronic otitis, Lyme disease, otosyphilis, or serum sickness. There can be hearing loss even if the infective agent is treated. This too is steroid-responsive.
The fifth is Cogan’s syndrome, which consists of a sudden onset of interstitial keratitis and severe vestibuloauditory dysfunction. This syndrome responds to high-dose steroids, but patients may eventually become resistant to the treatment.
The sixth category consists of AIED-like causes of hearing loss. Here, an idiopathic rapidly progressing bilateral sensorineural hearing loss that can lead to deafness often occurs in young people and consists of severe ear pain, pressure, and tinnitus. This condition is not responsive to immunosuppressive drugs, including steroids.
Defining Autoimmune Conditions
However, there are no perfect ways of diagnosing AIED. Indeed, according to Dr. Rauch, there is still controversy over the very nature of some types of AIED. There are strict criteria for confirming that a disease is autoimmune. These criteria have not been met for the condition commonly called AIED. It would be more accurate, he said, to call it immune-mediated inner ear disease (IMIED).
This doesn’t mean hearing isn’t affected by autoimmune disease. There are systemic autoimmune diseases, such as lupus, rheumatoid arthritis, ulcerative colitis and others that affect various organs, and occasionally affect the ear. So, yes, we do sometimes see hearing loss in a patient with one of these diseases. But it’s not common, Dr. Rauch said.
Statistics on the rates of AIED are so elusive that experts can only say the condition is rare.
The general opinion in otolaryngology is that there is an autoimmune component to idiopathic, rapidly progressive hearing loss where no other organs are involved. The idea was initially proposed in 1979 when it was found that even though an actual autoimmune disease could not be detected, patients responded to steroid treatment.
The hypothesis has been that somehow it’s immune-mediated. But no one has ever proven that it’s autoimmune, Dr. Rauch said. There have been no consistent autoimmune markers for the condition found in blood, and no definitive evidence from imaging or other tests either.
Of course, there are always exceptions to the rule, and about 15% of cases have some sort of abnormal blood work indicating immune dysregulation. Still, that means 85 percent of the time everything is normal, but the patient’s hearing is dropping rapidly, Dr. Rauch said.
What’s a Physician to Do?
So, how does an otolaryngologist handle a condition that has elusive causes? First, Dr. Rauch suggests not plunging straight into steroid treatment. The reason is that steroid doses are high, are administered for a lengthy period of time, and patients almost invariably suffer side effects. Instead, he suggests following the patient closely for at least a couple of months.
-Jeffrey Harris, MD, PhD
The best way to approach that is to do no treatment but to test the hearing once a month. And if it is AIED, what you will see is that at every test the hearing is a lot worse. If you see over a span of one, or two, or three months that the hearing keeps dropping, you can be quite confident that it’s worth a trial of steroids, Dr. Rauch said.
Dr. Harris added that not all progressive bilateral cases look or act like AIED. Those we treat are rapid over weeks, and asymmetrical-one ear going out fast then followed by instability of the other one soon after. Blood tests should be obtained, but steroids should be started before the results are back, he said.
On the other hand, if the hearing fluctuates, the problem might not be AIED. I don’t treat this with steroids, but that’s very controversial. I only treat if the hearing is going down, said Dr. Rauch. Because there is no test for AIED, treatment choice is purely up to individual doctors and their best judgment. In his experience with this sort of case, hearing will fluctuate regardless of whether or not patients are on steroid treatment.
On the other hand, Dr. Harris pointed out, not many conditions fluctuate without accompanying vertigo, except cochlear hydrops and AIED. So if they are not responding to the treatment for hydrops-that is, diuretics and salt-restrictive diet-then a trial of high-dose steroids would be a strong option.
Both agreed, however that if hearing continues to deteriorate, steroids are the treatment of choice. If hearing is dropping relentlessly, I figure AIED is a possibility and I treat the patient with high-dose prednisone, 60 milligrams per day for one month, and repeat the hearing test, Dr. Rauch said. If the hearing is substantially improved, then he opts for a six- to 12-month slow-taper regime.
But if after one month of high-dose prednisone there’s no hearing improvement, then I wean them off the drug and that’s the end of that-it’s a treatment failure, and the diagnosis is a mystery, Dr. Rauch said.
For some patients, a step in treatment might be intratympanic steroid injections, but this is highly controversial. There have been no controlled studies demonstrating the effectiveness of the treatment, Dr. Rauch said.
The dilemma in AIED in using intratympanic steroids is if you believe that the patient’s entire immune system is dysregulated, putting a few drops of steroid in their ear is really not treating the whole immune system-it’s treating one little place, the ear. If you believe the patient’s whole immune system is okay but there’s something wrong in the ear, then injecting the drug in the ear might have some logic. This is analogous to patients who are using systemic steroids for a condition such as rheumatoid arthritis, but occasionally need a steroid injection directly into a ‘hot’ joint.
Getting the evidence isn’t an easy task, Dr. Harris noted. AIED is rare, and getting enough patients to make a study powerful enough statistically is difficult. However, Dr. Harris does use intratympanic injections in patients who are clearly steroid-responsive, but who can no longer tolerate high-dose steroids.
We will try intratympanic injections of high-dose steroids into the middle ear to see if that will give these patients the same benefit that the oral steroids gave them, he said. If the patient responds, then the patients will be offered repeat injections.
However, the timing and regime for injections are a best guess. Studies still need to be done to sort out the effectiveness of intratympanic injections for steroid-responsive AIED, Dr. Harris said.
Overall, there isn’t much debate over oral steroids for some types of AIED. The efficacy of steroids in autoimmune deafness has been pretty well established, Dr. Harris said.
©2007 The Triological Society