"An Unusual Case of Bilateral Sudden Mixed Hearing Loss with Complete Remission": A Case Report and Pathophysiological Considerations.

Sudden-onset bilateral mixed hearing loss in adults is an extremely rare condition but challenging to diagnose and treat. Conductive hearing loss is associated with otitis media, while the simultaneous presence of a sensorineural component requires supplementary investigation for possible shared pathophysiological mechanisms. We report the case of a 41-year-old male who was admitted to our hospital with a 48 h history of bilateral, fast progressive hearing loss following a viral illness. The audiologic testing revealed bilateral severe mixed hearing loss. Tympanometry indicated the presence of middle-ear effusion, and myringotomy confirmed the existence of pressurized serous fluid. Treatment consisted of systemic and intratympanic corticosteroids, antibiotics, and supportive therapy. The patient had an unexpected full recovery of auditory function within one month. Multiple hypotheses were considered. We hypothesized the coexistence of unrelated conductive and sensorineural hearing loss or a unifying pathological process. Theories discussed include a direct viral insult to the cochlear structures or even pressure-mediated damage to the basal cochlea due to the simultaneous inward displacement of the oval and round windows. The complete resolution of hearing loss is the indicator of a reversible etiology, possibly due to transient inner ear dysfunction secondary to middle-ear pathology or viral infection. This case illustrates the complexity of diagnosing acute mixed hearing loss. This report emphasizes a rare case of sudden-onset bilateral mixed hearing loss with a complete recovery, contributing valuable insight into under-reported and diagnostically complex presentations.