Background: The pathogenesis of Idiopathic sudden sensorineural hearing loss (ISSNHL) is ambiguous. Stress is commonly defined as a cause of the disease. Serum levels of stress-related hormone (cortisol, growth hormone, aldosterone, ADH, ACTH) may be elevated in patients with ISSNHL patients.
Objectives: We aimed to determine whether psychological factors and stress hormones in patients are associated with the severity of hearing loss and therapeutic outcomes. We hypothesized that the stress hormone level in the disease sequence is a strong prognostic factor of ISSNHL. Additionally, we investigated whether the subjective degree of psychological stress is likely to contribute to the therapeutic prognosis of ISSNHL, as determined using questionnaires.
Methods: We conducted a prospective study of patients aged between 19 and 65 years admitted for the treatment of ISSNHL at our hospital. All patients underwent pure tone audiometry (PTA) on day 0, day 5 and 2 weeks after discharge. As an objective indicator of stress, we measured the level of HPA axis-related hormones. So, we measured serum cortisol, adrenocorticotropic hormone (ACTH), aldosterone and dehydroepiandrosterone sulfate (DHEAS) levels in the venous blood sample of patients on day 1 and day 5 after admission. In addition, for subjective stress measurements, depression and anxiety levels were assessed using self-reported questionnaires, Beck Depression Inventory (BDI), and Perceived Stress Scale (PSS) in the revised to Korean versions.
Results: Eighteen patients diagnosed with ISSNHL at the Department of Otorhino-laryngology were enrolled. Serum DHEAS level measured on day 1 showed a statistically significant correlation with the hearing threshold in the hearing test performed at the time of diagnosis (p = .037, correlation coefficients(r) = 0.541). Serum ACTH level was measured on day 1, and patients were classified into normal and elevated groups based on a threshold of 1.5 pg/mL; the normal group had better hearing thresholds in the first and second hearing test than the elevated group (p = .040, 0.015, respectively). In the stress-related questionnaires, the BDI score showed a statistically significant correlation with the last hearing test (p = .015, correlation coefficients(r) = 0.613).
Conclusion: We demonstrated the possible role of stress-related hormones in the pathogenesis of ISSNHL and suggest that depressive stress response can be a strong predictor of treatment response in patients with ISSNHL. However, the impact of response to stress on the inner ear and endolymph homeostasis remains unknown. Since this is a cross-sectional study, we can only comment on the relationship between stress and ISSNHL, not a causal relationship. Further investigation is necessary to identify the mechanism of interaction between stress and hearing ability in the inner ear.
Keywords: HPA-axis; ISSNHL; Idiopathic sudden sensorineural hearing loss; hearing loss; questionnaire; stress.