Recurrent Sudden Sensorineural Hearing loss: Review of 30 Cases with the Clinical manifestations and Outcomes Pei-Hsuan Wu, Cheng-Ping Shih Department of Otolaryngology–Head and Neck Surgery, Tri-Service General Hospital

Introduction Sudden sensorineural hearing loss (SSNHL): an abnormality of the cochlea, auditory nerve, or higher aspects of central auditory perception or processing Definition: sensorineural hearing loss of at least 30 dB at 3 consecutive frequencies occurring over 3 days. Incidence: 5 to 20 per 100,000 individuals

Introduction Idiopathic sudden sensorineural hearing loss (ISSNHL): SSNHL with no identifiable cause despite adequate investigation. Others: Infections, Neoplasms, Trauma, Autoimmune diseases, Vascular diseases 32% to 65% of cases of SSNHL may recover spontaneously - systemic and topical steroids - antiviral agents - rheologic agents - diuretics - hyperbaric oxygen treatment - surgeries - observation

Material and Method Included patients from 2008 to 2018. Exclusion criteria: perilymphatic fistulas, acoustic trauma, Ménière's disease, labyrinthitis, autoimmune hearing loss or acute low-tone hearing loss that showed fluctuating hearing loss over several weeks or months Inclusion criteria: appropriate treatment within 2 weeks, no history of vestibular symptoms, and availability for follow-up at the study hospital

Material and Method

Results

Results

Results

Results Good =Type I+II Poor =Type III+IV

Results Good =Type I+II Poor =Type III+IV

Discussion Prognostic factors: - age - the presence or absence of vertigo - the severity of hearing loss - Underlying diseases, hypertension - the shape of the audiogram - timeliness of initial treatment. Steroid sensitivity Glucocorticoid responsiveness can also be influenced by genetic variations in interleukins and their receptors (Vambutas et al., 2009; Pathak et al., 2011). We often think of the steroid responsive forms of hearing loss as being spontaneous or induced by some sudden metabolic, vascular, or inflammatory event. However, recent studies have shown that some forms of sudden hearing loss and Meniére’s disease are correlated with gene alterations. If these defects precipitate the manifestation of hearing or vestibular symptoms, they may be less likely to respond to steroids. It is interesting to speculate that Rauch’s description of the Meniére’s patient as one who represents that phenotype of a fragile ear with defective homeostatic mechanisms may actually have a genotypic basis (Rauch, 2010). Thus, the actual cause of hearing loss or vertigo may be a genetic malformation that is not fully compensated with a steroid treatment.

Conclusion The cause of recurrent hearing loss remains undetermined. The hearing improvements in 2nd episode may be related to 1st episode The hearing improvements in 2nd episode are poorer than in 1st episode The hearing improvements in 2nd episode may be not related to the side of affected ear It can occur in association with systemic diseases, such as hypertension or diabetes mellitus, suggesting that insufficient cochlear perfusion is, at least in part, a risk factor for the recurrence of sudden deafness. Recurrent viral infection might be included in the etiology of recurrent SSNHL, but this remains unclear and further study is needed.

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