Vulnerable Frequency As An Independent Prognostic Factor For Full-frequency Sudden Sensorineural Hearing Loss

Objective: Sudden sensorineural hearing loss(SSNHL)is a frequently encountered otological emergency in clinical practice.The main features of SSNHL are its sudden onset,unknown etiology,and underlying mechanism.While SSNHL has a low impact on mortality,its severe hearing impairment and poor prognosis can significantly reduce patients’ quality of life.Early identification of patient prognosis and assessing the need for intensive treatment are crucial to maximize the chances of patient recovery.This study aims to explore the impact of hearing loss on the prognosis of full-frequency SSNHL across different frequencies,building on previous research demonstrating the varying vulnerability of cochlear hair cells at different frequencies.Methods: Clinical data of patients diagnosed with full-frequency SSNHL and admitted to the Otorhinolaryngology Head and Neck Surgery of the Second Affiliated Hospital of Anhui Medical University between January 2018 and May 2022 were retrospectively collected and analyzed.The patient’s hearing condition was thoroughly examined using both electrical audiometry and acoustic immittance,recording hearing thresholds across various frequencies and collecting accompanying symptoms for adjustment.Previous studies have identified predictors of cardiovascular inflammatory and oxidative stress that have prognostic value for full-frequency SSNHL.These predictors were collected and included as covariates in the final analysis.Following guidelines,patients were recommended for comprehensive treatment.After two weeks of treatment,patients were categorized into two groups based on their hearing recovery:the response group(with a Pure-Tone Average improvement ≥30 d B at the frequencies of damage,or improvement to normal levels)and the non-response group(with a PTA improvement <30 d B at the frequencies of damage).Data analysis was performed using SPSS 26.0 software,while Graph Pad Prism 8.0 software was utilized for graphing purposes.Continuous data are presented as mean ± standard deviation or median(interquartile range),while categorical data are expressed as frequency(percentage).Chi-square test was employed to analyse classification variables between the two reaction groups.The Kolmogorov-Smirnov test was employed to assess the distribution pattern of the data.For comparing continuous variable data with normal distribution,the two-sample t-test was utilized,while the Mann-Whitney U nonparametric test was employed for comparing continuous variable data with non-normal distribution.Linear correlation analysis was performed to evaluate the association between pre-treatment hearing thresholds and post-treatment hearing improvement across different frequencies.Receiver Operating Characteristic(ROC)curve analysis was employed to assess the relationship between pre-treatment hearing thresholds and treatment prognosis.A logistic regression model was utilized to estimate the odds ratio(OR)and 95% confidence interval(CI)for treatment prognosis.Prior to multivariate logistic regression analysis,the variance inflation factor(VIF)was used to assess multicollinearity among variables.A p-value of <0.05 was considered statistically significant.Results: A total of 255 patients with full-frequency SSNHL,comprising 139 males and116 females,were included in this study.The median age of the study population was44.00(30.00-52.00)years.Out of the 255 patients,65 presented with accompanying vertigo.One hundred forty-eight patients had a flat hearing pattern,while 107 patients were completely deaf.The difference analysis revealed that the hearing thresholds at 4k Hz and 8 k Hz were significantly lower in the response group than in the non-response group(p<0.05),while no significant difference was observed in PTA(p=0.065).The correlation analysis results indicated that there was a negative correlation between pre-treatment hearing thresholds at 4k and 8k Hz and hearing improvement after comprehensive treatment(p < 0.05).However,no significant correlation was observed between hearing thresholds at other frequencies and PTA with hearing improvement(p>0.05).ROC curve analysis indicated that pre-treatment hearing thresholds at 4k and8 k Hz were predictive of poor treatment response,with corresponding areas under the curve of 0.624(95% CI,0.555-0.694)and 0.700(95% CI,0.631-0.769),respectively.After conducting multivariate logistic regression analysis,it was found that only two factors,vertigo(OR,95% CI;0.265,0.102-0.684)and hearing threshold at 8k Hz before treatment(OR,95% CI;0.943,0.916-0.971),were significantly associated with treatment prognosis.Conclusions: In the adjusted model,the hearing threshold at vulnerable high frequency before treatment was found to be independently associated with the prognosis of full-frequency SSNHL,while hearing thresholds at other frequencies were not significantly associated.Our study did not find a significant association between PTA before treatment and the prognosis of full-frequency SSNHL.