Autoimmune Inner Ear Disease
Brian McCabe, MD, first described autoimmune sensorineural hearing
loss in his landmark 1979 paper. McCabe described a series of 18
patients whose "clinical pattern did not fit with known
entities and thus seemed to merit distinctive categorization."
Since that time, autoimmune inner ear disease (AIED) or
immune-mediated sensorineural hearing loss, has taken its place as
a cause of sensorineural hearing loss and vestibular symptoms.
AIED occurs when the body's immune system attacks cells in
the inner ear that are mistaken for a virus or bacteria. AIED is a
rare disease occuring in less than 1% of the 28 million Americans
with a hearing loss. It can happen in isolation (as just
labyrinthine disease) or as part of other systemic autoimmune
disorders. Twenty percent of patients have other autoimmune
diseases, such as rheumatoid arthritis or lupus.
The exact clinical description can vary somewhat; however, most
agree that the syndrome follows a fairly typical course. AIED will
manifest as rapidly progressing, sensorineural hearing loss that is
most commonly bilateral. Typically, it begins unilaterally and
ultimately affects the other ear, and it can occur suddenly. Word
recognition is usually disproportionately poor. Vestibular symptoms
can have a fluctuating course during the active phase of disease.
Additionally, tinnitus, as a ringing, roaring, or hissing noise,
may be present. Diagnosis can be difficult because AIED can mimic
other ear disorders. In any patient with presumed AIED, it is
essential to rule out other causes of progressive sensorineural
hearing loss, such as acoustic neuroma, neurosyphilis, and
Meniere's, as well as other metabolic conditions.
Because of the difficulty in the differential diagnosis of AIED,
many have proposed the use of lab tests to assist in the medical
diagnosis. McCabe originally recommended an "immune
screen" to include
- Erythrocyte sedimentation rate, which is a general indicator
of inflammation;
- Rheumatoid factor, which is a marker for rheumatoid arthritis
and other autoimmune diseases;
- Anti-nuclear antibody titer, to check for lupus and other
autoimmune diseases;
- quantitative immunoglobulin determination; and
- A leukocyte migration inhibition test.
Later, Campbell and Klemens (2000) listed other medical tests
they commonly use to detect AIED:
- CBC (complete blood count) to check for leukemia or other
hemolytic disorders;
- FTA/ABS blood screen for syphilis;
- MRI, with contrast, of brain and cerebellopontine angle to
check for MS, vascular lesions, and space-occupying lesions;
- Lymphocyte blast transformation to check for inner ear
antigen, which may underlie AIED (the efficacy of this test is
controversial);
- Rheumatoid factor and anti-nuclear antibody, as mentioned
above;
- Lipid panel to check for dylipemias; and
- Steroid trial.
Many have also cited the use of the test for heat shock
protein-70 (HSP-70). Positive response on this test correlates well
to how well a patient will respond to steroids (Derebery,
2001).
Ultimately, many diagnose AIED by the positive response to
steroid treatment. Steroids (dexamethasone, prednisone,
prednisolone) are often used for the treatment of AIED. High doses,
often in doses of 40-80 gm/day, may be useful in the initial
management of AIED. Unfortunately, hearing improvement is rarely
sustained and unacceptable side effects from the corticosteroid
therapy soon follow (Matteson et al., 2003). Other agents such as
Methotrexate (a chemotherapeutic agent) and immune modifying drugs
such as Enbrel or Imuran are used and are being investigated.
Reportedly, 6% of the AIED patients progress to the point of
profound loss. Most do extremely well with an implant.
As mentioned above, 20% of patients have other autoimmune
diseases. Here is a list of some of the systemic immune diseases
that have been known to have AIED:
- Cogan's syndrome-this syndrome includes ocular
inflammation and associated vestibulo-auditory dysfunction,
- Relapsing polychondritis,
- Systemic lupus erythematosus,
- Wegener's granulomatosis,
- Polyarteritis nodosa,
- Sjogren's syndrome, and
- Lyme disease.
Barbara "Barbie" Bell-Lehmkuhler
References
Campbell, K.C., & Klemens, J. J. (2000). Sudden hearing loss
and autoimmune inner ear disease.
Journal of the American Academy of Audiology, 11,
361-367.
Derebery, J. (2001, November 26). Interview with Jennifer
Derebery, M.D, House Ear Clinic, Autoimmune Inner Ear Disease.
Audiology Online
. Available from
http://www.audiologyonline.com/interview/displayarchives.asp?interview_id=92
.
Matteson, E. L., Fabry, D. A., Strome, S. E., Driscoll, C. L.,
Beatty, C. W., & McDonald, T. J. (2003). Autoimmune inner ear
disease: Diagnostic and therapeutic approaches in a
multidisciplinary setting.
Journal of the American Academy of Audiology, 14,
225-230.
McCabe, B. (1979). Autoimmune sensorineural hearing loss.
Annals of Otolgy, Rhinology and Laryngology, 88,
585-589.
About the Author
Barbie Bell has been a practicing clinical audiologist for 20
years now. She got her start at the House Ear Clinic in Los Angeles
immediately after grad school. In 1993, she moved to the Denver
metro area where she continues to work clinically at RidgeGate
Hearing Clinic. Barbie has also done software training for a
hearing aid manufacturer and now works part time as a professional
reviewer of audiograms with Associates in Acoustics. She is
pursuing her AuD from Central Michigan University with hopes of
graduating in the spring of 2006.
This article first appeared in the Vol. 5, No. 1,
January/February 2006 issue of
Access Audiology.