Prevalence and Intriguing Clinical Profiles of Autoimmune Inner Ear Diseases in Sudden Sensorineural Hearing Loss.

Introduction: Sudden sensorineural hearing loss (SSNHL) is idiopathic in 70-90% of cases with 10-30% linked to vascular injuries, viral infections, or autoimmune inner ear disease (AIED). AIED contributes to less than 1% of all hearing losses, categorized into primary, affecting only the inner ear, and secondary, associated with systemic autoimmune diseases (SAID). This study examines the prevalence and features of AIED in SSNHL in a tertiary referral center.

Materials and methods: We conducted a prospective study from November 2021 to December 2022 including SSNHL patients who exhibited symptoms like hearing loss or tinnitus. Evaluations included tympanometry, pure tone audiometry, and blood tests, with suspected AIED cases further assessed by rheumatologists using Lobo's diagnostic criteria. Treatment responses were monitored through regular audiometry updates.

Results: Out of 694 SSNHL patients, 43 (6.2%) were diagnosed with AIED, of which 36 (83.7%) had primary AIED and 7 (16.3%) had secondary AIED linked to conditions like Sjögren's syndrome and systemic lupus erythematosus. Treatment response was seen in 19.4% of primary and 42.9% of secondary AIED cases.

Conclusion: The prevalence of AIED in SSNHL patients was found to be 6.2%, with a notable fraction also suffering from SAID. Responses to treatment were positive in about a third of these cases, highlighting the importance of interdisciplinary management for this rare yet significant cause of SSNHL.