According to the National Cancer Institute, autoimmune disease is a condition where our natural immune system mistakenly attacks our healthy tissues, treating them as foreign. The result is inflammation and a whole host of signs and symptoms. In the late 1970s, a famous ENT pioneer at the University of Iowa, Dr. Brian McCabe, was the first to describe the effectiveness of corticosteroid treatment for rapidly progressive hearing loss in a group of patients.
Autoimmune inner ear disease was first reported because of the clinical response to rapidly progressive hearing loss to corticosteroids.
Autoimmune inner ear disease is a clinical diagnosis based on several factors including history, physical examination, hearing tests, and antigen non-specific laboratory testing.
Treatment of autoimmune inner ear disease requires high-dose corticosteroids for extended periods of time. Rarely, cytotoxic agents are used. There is a limited role for intratympanic injections of steroids and no role for surgical intervention.
The fact that corticosteroids worked suggested that the cause of the hearing loss was a result of an autoimmune disease.
The connection of hearing loss to autoimmune diseases
The keys to the diagnosis were that the hearing loss was rapidly progressive over weeks or months, fluctuating, and involved both ears. In addition, about half of the patients had vertigo and balance problems.
Not surprisingly, years later it has been discovered that many of these patients with autoimmune disease hearing loss also had other coexisting autoimmune diseases. About one-quarter have diagnoses of rheumatoid arthritis, ulcerative colitis, systemic lupus erythematosus (SLE), and polyarteritis nodosa.
Although there is no evidence as to why, autoimmune inner ear disease is more common in females. It occurs most commonly in ages 20 to 50 years and is uncommon in children.
How do autoimmune inner ear disease cause hearing loss and balance problems?
No one knows for sure, but the thought is that there is a direct attack by the immune system on the inner ear and its delicate mechanism. It is also possible that the nerves within the inner ear and those leading to the auditory part of the brain may be affected.
The diagnosis of autoimmune inner ear disease is a clinical diagnosis. This means there is no specific test. The patient is diagnosed based on the clinical course, immune test results, hearing tests, and the response to treatment. Most importantly, if the hearing improves with a trial of immunosuppressants, that confirms the diagnosis.
Many patients with autoimmune inner ear disease also have Meniere’s disease or idiopathic endolymphatic hydrops, also an autoimmune disease. In some studies, the incidence of having both autoimmune inner ear disease and Meniere’s was 50%. Meniere’s disease patients have episodic, debilitating vertigo.
Besides a hearing test, what other tests can be done?
The main test your doctor will order is called an antigen-nonspecific test. This test is used as a routine screening for systemic immunologic dysfunction. But as the name suggests, antigen-nonspecific means that it is not known to correlate specifically with autoimmune inner ear disease.
Some of the tests your doctor may order may include the following:
- Levels of circulating immune complexes.
- Complement levels (C3, C4).
- Antinuclear antibody levels.
- Rheumatoid factor.
- Acute phase reactants: Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP).
Of note, it is common to see doctors order the ESR and CRP tests. ESR indirectly measures the level of inflammation in the body. CRP is made in the liver and shows a general response to acute inflammation or infection.
It is important to note that even with abnormally elevated ESR and CRP levels, the diagnosis of autoimmune inner ear disease must be made clinically, considering all the other signs, symptoms, hearing tests, and patient history.
What happens if I am diagnosed with autoimmune inner ear disease?
The most important consideration is that there is hope. No one knows the natural history of autoimmune inner ear disease, particularly if it goes untreated. Many people successfully regain much, if not all of their hearing with treatment.
The best strategy is to get diagnosed and diagnosed early. Anyone with rapidly progressive hearing loss with no other apparent cause should be evaluated for aggressive corticosteroid treatment. This means longer-term therapy, not short bursts, as they seem to be ineffective. Of course, caution must be taken with corticosteroid treatment in patients with coexisting conditions such as diabetes mellitus, glaucoma, hypertension, or peptic ulcer disease.
There are no standard regimes for corticosteroid treatment. Most doctors advocate high-dose prednisone of 1 mg/kg/day for one month, followed by a tapering dose.
Your hearing may increase and decrease during treatment. Often, a higher dose of prednisone is needed to maintain hearing improvement. Every patient responds to steroid treatment differently.
Some patients do not see an improvement in their hearing despite high doses of steroids. These patients may need an alternative treatment called cytotoxic therapy. Cyclophosphamide is an example and sometimes recommended treatment along with steroids.
Cyclophosphamide can have adverse effects such as myelosuppression (bone marrow), hemorrhagic cystitis (bladder inflammation), infertility, and an increased risk of malignancy (cancer). Therefore, these treatments should be carefully planned and prescribed only when necessary.
About 60% of patients respond to corticosteroid therapy which is defined as an improvement of 15 decibel (dB) at one frequency, 10 dB at two frequencies, or an overall improvement of speech discrimination scores.
Other treatments that have been tried include plasmapheresis, where the patient’s whole blood is filtered to remove antibodies, antigens, and immune complexes. The procedure is expensive, has its risks, and is considered only as an adjunctive therapy since further research needs to be performed to determine its safety and efficacy in the treatment of autoimmune inner ear disease.
Surgery is not an option for autoimmune inner ear disease. However, there are some doctors who will try intratympanic injections (medications through the eardrum) of steroids under local anesthesia. The results are mixed and cannot be justified in most patients.
- National Cancer Institute. Definition of autoimmune disease.
- The annals of otology, rhinology and laryngology. Autoimmune sensorineural hearing loss.
- Clinical Otolaryngology. Current understanding of the pathogenesis of autoimmune inner ear disease: a review.
- Current Opinion in Otolaryngology and Head Neck Surgery. Issues, indications, and controversies regarding intratympanic steroid perfusion.