Control of chronic otitis media and sensorineural hearing loss in C3H/HeJ mice: glucocorticoids vs mineralocorticoids.

OBJECTIVE

The impact of glucocorticoids and mineralocorticoids on chronic otitis media (COM) in toll-like receptor 4-deficient C3H/HeJ mice was investigated.

STUDY DESIGN

To evaluate control of COM by steroids with differences in their anti-inflammatory (prednisolone, dexamethasone), and fluid absorption functions (fludrocortisone, aldosterone). A minimum sample size of five animals for each group was required based on power analysis calculations. Sample sizes ranged from 7 to 17 mice per treatment group.

SUBJECTS AND METHODS

Auditory brain stem response (ABR) thresholds were performed at baseline, 2 weeks and 4 weeks. Histopathologic test results were evaluated on all mice ears at the end of the study.

RESULTS

Analysis of variance (ANOVA) of ABR threshold change showed significant treatment effects (P < 0.05) by both steroid types at all time intervals and ABR frequencies except 4 weeks/8 kHz. Histologic assessment showed prednisolone-treated mice (62%) had a higher rate of clearance of middle and inner ear inflammation than control mice (4%).

CONCLUSION

It was concluded that steroid treatments can improve the physiology of chronic middle and inner ear disease seen with COM.