In addition to confirmed AISNHL in all 8 patients, tinnitus had been present in 2 patients, vertigo in 3, and Meniere syndrome in 2.
AISNHL is most likely an immune-mediated condition, although there is no direct evidence of its autoimmune etiology.
Because of the uncertainty over the cause of AISNHL, otologists have tried many treatment regimens with various results.
(21) Van Wijk et al conducted a preliminary study of 9 patients with AISNHL who were treated with transtympanic infliximab and found the results encouraging.
However, all of the patients in our study had been selected for infliximab treatment because their AISNHL was already refractory to all recommended treatments, including steroids, methotrexate, and/or cyclophosphamide.
Since the initial description of AISNHL, this condition has been found to occur in association with many immunologic and autoimmune disorders such as systemic lupus erythematosis (SLE), rheumatoid arthritis, and ulcerative colitis.
AISNHL may cause hearing loss of any pattern, tinnitus, and dizziness.
Patients were suspected of having AISNHL if they demonstrated at least a 30-dB loss at three or more frequencies between 250 and 8,000 Hz (with or without a decrease in SDS) in addition to a subjective hearing loss in the affected ear(s) at the time of the initial audiogram.
The presence or absence of four specific antigens--HLA B35, CW4, CW7, and DR4--was determined so that we could analyze the proposed association with AISNHL (the presence of B35, CW4, and CW7 and the absence of DR4).
The pretreatment audiometric analysis is a crude control tool, but it helps define the natural history of AISNHL. We compared the early PTA and SDS values of the 15 patients in the control group with those that were later obtained during audiometric testing administered just prior to the institution of therapy (table 4); we did the same for the four controls who refused treatment, using the data obtained at their final visit (table 5).
Thus, as McCabe has suggested, there might be a window of opportunity to treat AISNHL before irreversible inner ear damage occurs.
(11) Further evidence has suggested that AISNHL is associated with the presence of an antibody to a 68 kD inner ear protein (isolated by Western blot assay).