Autoimmune inner ear disease (AIED) was first described in 1979 as a sensorineural hearing loss that is usually bilateral, often fluctuates, progresses over weeks to months and is responsive to treatments for autoimmune disease [1, 2]. It is a rare condition that is estimated to account for less than 1% of all hearing impairment . While conventional sound booth audiograms are the gold standard for the assessment of a patient’s hearing, they are relatively time consuming, require the expertise of a trained audiologist, and provide only a brief snapshot of the patient’s hearing. While this does not pose a problem for most forms of hearing loss, it can be difficult to adequately assess and treat a patient with AIED using conventional audiometry alone given the rapidly fluctuating nature of this disease.
AIED can be classified as primary AIED (immune mediated disease limited to the inner ear) or secondary AIED (immune mediated inner ear disease as a manifestation of a systemic autoimmune process) . Secondary AIED is associated with a wide array of systemic conditions including Behçet’s, Wegener’s, Hashimoto’s thyroiditis, rheumatoid arthritis, and lupus [2, 4, 5].
Corticosteroids are the gold standard medical treatment modality for AIED and have been shown to be beneficial in 70% of cases . While corticosteroids are the only medications that have been consistently proven to be of benefit , several other therapies have been employed for the treatment of recalcitrant disease. Cyclophosphamide and methotrexate have been shown to reverse disease progression, although these are associated with significant toxicity including myelosuppression, infertility and increased risk of malignancy. Although costly and resource intensive, plasmapheresis has also been suggested as an adjunct to steroids or cytologic agents for patients with refractory disease , and has even been shown to allow as many as 75% of patients to wean from immunosuppression . Biologic agents such as Etanercept and Rituximab have been studied with conflicting results [9, 10]. Studies have also investigated the role of commonly used transplant immunosuppressants such as azathioprine  and mycophenolate . While showing promising results, these treatments are often associated with significant side-effect profiles and have not become commonly employed in the treatment of AIED.
As is the case with many types of hearing loss, rehabilitation with amplification can decrease morbidity. That said, amplification can be a challenge for patients with AIED given the rapidity and severity of fluctuations. Therapeutic planning (including steroids, hearing aids and implantation) should be guided by data, but currently only snapshots are available and no validated home diagnostics are available. Finally, patients who cannot tolerate or who have failed medical management can be considered for cochlear implantation. However, given the sometimes normal hearing of a person with AIED it is essential to frequently document the hearing troughs prior to proceeding with surgery in order to understand the patient’s real-world experience.
In order to create a clear picture of the rapid changes in hearing associated with AIED frequent audiograms are necessary. Typically, a routine paediatric audiogram takes 15 min at our institution, and is associated with an overall cost of approximately $300 CAD. Thus, it is not feasible to perform conventional audiometry on a daily basis. However, with the advent of mobile tablet audiometery (Shoebox Audiometer - Clearwater Clinical Limited, Ottawa, Canada) it is possible to obtain valid results in a quiet room using self-testing methods at home. The tablet audiometer is a calibrated iPad (Apple Inc, Cupertino California) application that is paired with standard audiometric transducers that enables patients to perform their own audiogram by playing a validated game. The tool is Health Canada approved as a medical device, and has been internally and externally validated as an accurate tool for self-assessing hearing outside of a conventional sound booth [13, 14].
Given the associated logistical and financial barriers associated with frequent audiometry, no previous study has used this technique to document the immense frequency and severity of fluctuations associated with AIED. Using the tablet audiometry device, our study aimed to use frequent home audiograms to evaluate the variability and progression of these fluctuations in a single pediatric (teenage) patient over a 9-month period.