Prognostic Factors in Sudden Sensorineural Hearing Loss

Abstract

Background: Sudden sensorineural hearing loss (SSNHL) is still a complex and challenging process which requires clinical evidence regarding its etiology, treatment and prognostic factors. Therefore, determina-tion of prognostic factors might aid in the selection of proper treatment modality. Aims: The aim of this study is to analyze whether there is correlation between SSNHL outcomes and (1) sys-temic steroid therapy, (2) time gap between onset of symptoms and initiation of therapy and (3) audiological pattern of hearing loss. Study Design: Retrospective chart review.Methods: Patients diagnosed at our clinic with SSNHL between May 2005 and December 2011were reviewed. A detailed history of demographic features, side of hear-ing loss, previous SSNHL and/or ear surgery, recent up-per respiratory tract infection, season of admission, du-ration of symptoms before admission and the presence of co-morbid diseases was obtained. Radiological and audiological evaluations were recorded and treatment protocol was assessed to determine whether systemic steroids were administered or not. Treatment started < =5 days was regarded as " early" and > 5 days as " de-layed" . Initial audiological configurations were grouped as " upward sloping" , " downward sloping" , " flat" and " profound" hearing loss. Significant recovery was de-fined as thresholds improved to the same level with the unaffected ear or improved > =30 dB on average. Slight recovery was hearing improvement between 10-30dB on average. Hearing recovery less than 10 dB was ac-cepted as unchanged. Results: Among the 181 patients who met the inclusion criteria, systemic steroid was administered to 122 pa-tients (67.4%), whereas 59 (32.6%) patients did not have steroids. It was found that steroid administration did not have any statistically significant effect in either recov-ered or unchanged hearing groups. Early treatment was achieved in 105 patients (58%) and 76 patients (42%) had delayed treatment. Recovery rates were no different in these two groups; however, when unchanged hearing rates were compared, it was statistically significantly lower in the early treatment group(p< 0.05). When hearing outcomes were compared ac-cording to initial audiological pattern, significant recov-ery and unchanged hearing rates did not differ between groups; however, slight recovery rate was highest in the " flat" type audiological configuration (p< 0.05).Conclusion: According to this patient series, oral steroid therapy does not have any influence on the outcomes of SSNHL. However, mid-frequency hearing loss of flat type and initiation of treatment earlier than 5 days from the onset of symptoms, seem to have positive prognos-tic effects. Further randomized controlled subject groups might contribute to determine prognostic factors of SSNHL