Autoimmune inner ear disease
Autoimmune inner ear disease is a condition where the bodies’ own immune system attacks the ear. This attack on the ear may be an isolated event or it may be part of a general autoimmune condition involving other parts of the body. The cochlea of the inner ear has it’s own immunity and the endolymphatic sac is capable of producing antibodies in response to antigens.
AIED presents with rapidly progressive, often fluctuating bilateral sensorineural hearing loss (SNHL). It usually occurs over weeks to months. Patients may also be aware of fullness in the ears and tinnitus. Dizziness occurs in 50% of patients. In rare cases it may present as bilateral vestibulopathy, preserving the hearing. Sometimes only one ear may be involved, but this is rare.
The true incidence is not known. It probably accounts for less than 1% of sensorineural loss in patients. It is more common in female patients between 20 and 50 years and in patients with systemic autoimmune disease. It is estimated that 20% of bilateral Meniere’ disease may be due to AIED.
A patient with a genetic susceptibility develops AIED when exposed to a specific unknown environmental trigger. The trigger may be a virus, or a toxin.
The diagnosis is based on the typical history, exclusion of other causes and the response to steroids. Blood tests are not accurate enough to confirm the diagnosis of AIED but may be of benefit to investigate for systemic autoimmune disease.
Steroids usually improve symptoms temporarily but are unlikely to cure a patient. Side effects of long-term steroid treatment limit its value. Cytotoxic chemotherapeutic drugs and anti-tumor necrosis factor (anti- TNF) may also be prescribed.
Hearing aids may be of benefit for patients with hearing loss. In severe cases cochlear implantation (CI) may be the only option to restore hearing. Vestibular rehabilitation exercises are indicated for patients with bilateral vestibulopathy.