Only a few cases in the literature reported an association of TA with SNHL. Hearing loss is often progressive, although it can be stable or fluctuating; is usually bilateral and asymmetric; develops over several weeks to months; and mainly involves high frequencies. SNHL may also present as a SSNHL. A good response to corticosteroid therapy has been reported for SNHL in TA, although it may also persist despite therapy. Recently, Ralli et al. described a case of a 36-year-old woman with TA who had two episodes of SSNHL involving one ear at a time with an 11-month delay between each episode of treatment with hyperbaric oxygen therapy associated to corticosteroids, with significant improvements in both ears.
Relapsing polychondritis (RP) is a rare connective tissue disorder affecting organs containing collagen, such as the eye, cartilage tissue, and skin. The diagnosis is based on clinical features and no specific test for this disease is available; thus, definitive diagnosis takes a long time, and often, the prognosis is poor. Recurrent bouts of inflammation may lead to a permanent destruction of involved structures such as cartilage of the ears, nose, larynx, tracheobronchial tree, and cardiovascular system. McAdam et al. proposed diagnostic criteria for RP when three or more of the six clinical features are present: recurrent chondritis of both auricles; nonerosive, seronegative inflammatory polyarthritis; chondritis of the nasal cartilages; ocular inflammation (conjunctivitis, keratitis, scleritis, and uveitis); respiratory tract chondritis affecting laryngeal and tracheal cartilages; and cochlear and/or vestibular dysfunction (SNHL, tinnitus, and vertigo).
Auricular chondritis is a quite specific sign of RP. It is present in 20% of patients at the onset of the disease and in 90% during the course of the disease. One or both ears can be affected. The ear concha is swollen, red, or less often purplish, hot, and painful even at the slightest contact. The ear lobe, which does not contain the cartilage, is spared.
Audiovestibular impairment is reported in 40-54% of all patients with RP. These changes can represent the initial symptoms heralding the outbreak of the disease or appear after the onset of other symptoms. Typical manifestations can be bilateral or unilateral, are usually of sudden onset, and appear as perceptive deafness or tinnitus combined with or without vertigo and nausea. CHL can be a result of a serous otitis following chondritis of the eustachian tube. Further, the SNHL in RP patients has been suggested to be the result of inflammation of the internal auditory artery or its cochlear branch or due to autoantibodies against the cochlea and vestibular organ. This could explain the near-complete hearing recovery in patients after treatment with corticosteroids.
Wegener's granulomatosis (WG) is an autoimmune disease of unknown aetiology characterized by necrotizing granulomatous inflammation of the respiratory tract, necrotizing glomerulonephritis, and systemic vasculitis that affects predominantly small vessels.
Although the pulmonary, nasal, and renal manifestations of WG are well described, hearing symptoms are less appreciated. Studies available in the literature report a prevalence of audiovestibular symptoms in 8% to 65% of patients with WG, mainly auditory symptoms with SNHL or CHL in cases of WG involving the middle ear. Audiometric patterns of WG have been described as typically flat, although sometimes additional high frequency losses may coexist and differential diagnosis with noise exposure or age-related hearing loss may be difficult. Hearing impairment may also present as SSNHL; Bakthavachalam et al. identified that hearing loss was present in 56% of patients suffering from WG and SSNHL was the most common form, occurring in 47% of cases.
Hearing loss may also be a presenting symptom of WG. SNHL in WG is believed to be largely irreversible, therefore potentially adding to the patient's cumulative disability. SNHL evaluation and monitoring are therefore recommended for appropriate patient management and could suggest a worsening of disease that may address to a specific treatment like cyclophosphamide rather than either methotrexate or azathioprine.
Susac's syndrome (SS) is a rare immune disease characterized by encephalopathy, branch retinal artery occlusion, and SNHL. SS has a higher prevalence in females, with a male: female ratio of 1 : 3.5.
The pathophysiology of SS is not entirely clear. Antiendothelial cell antibodies (AECAs) in SS have been recently documented. Potential targeted antigens suggested in studies focusing on AECAs include cytoskeletal proteins (beta-actin, alpha-tubulin, and vimentin), glycolytic enzymes (glucose-3-phosphate-dehydrogenase and alpha-enolase), and the prolyl-4-hydroxylase beta subunit, a member of the disulfide isomerase family.
Clinical manifestations of SS are thought to be caused by autoimmune-mediated occlusions of microvessels in the brain, retina, and inner ear that lead to a characteristic clinical trial of central nervous system (CNS) dysfunction. At clinical onset, the most common manifestations are CNS symptoms, observed in two-thirds of patients, followed by visual symptoms and hearing disturbances. Unfortunately, only a small number of patients (around 13%) show the characteristic symptoms of SS at disease onset; thus, definitive diagnosis is often delayed.
Hearing loss can be a dramatic and severely debilitating feature of SS; it may be mild and insidious or may be fluctuating, mimicking Meniere's disease. A loss of low or middle frequencies is typical, suggesting a vulnerability of the cochlear apex to microinfarction; loss of high frequencies can also occur. Hearing loss often occurs overnight and may affect both ears. Dorr et al. refer to this clinical behaviour as the "bang-bang hearing loss". Severe hearing loss is often accompanied by vertigo and a roaring tinnitus; the occlusion of cochlear and vestibular arterioles may be the cause of these symptoms. In these patients that often develop severe/profound SNHL and can no longer benefit from hearing aid amplification, cochlear implantation is a valid therapeutic option.
Primary Sjogren's syndrome (pSS) is a chronic autoimmune disease characterized by xerostomia and xerophthalmia due to lymphocyte infiltration of both salivary and lacrimal glands. It may also occur as a systemic disease involving the kidneys, lungs, liver, vessels, and lymph nodes. pSS mainly affects women in the fourth-fifth decade of life, and presenting symptoms are often oral and ocular. In this context, autoantibodies to cardiolipin and M3 muscarinic receptors (mAchRs) in the serum of pSS patients are suspected to play a pathogenic role in the onset of progressive hearing loss and neurological complications.