Early Dexamethasone Treatment Enhances Hearing Preservation after Pneumococcal Meningitis: An Animal Study

Abstract

Objective: We aimed to investigate the effects of early and late dexamethasone treatment combined with antibiotics on hearing preservation on experimental rat pnemococcal meningitis model. Materials and Methods: Thirty rats with confirmed diagnosis of meningitis after intracisternal S. pneumonia injection were randomly assigned to 3 groups. Animals in group 1 recieved intramuscular (im) ceftriaxone for 7 days, animals in group 2 recieved im dexamethasone on days 4-7 adjunct to im ceftriaxone treatment and animals in group 3 received im dexamethasone on days 1-4 adjunct to im ceftriaxone treatment. Hearing status of all rats were evaluated by auditory brainstem responses (ABR) on days 7 and 28 and categorized as normal hearing, moderate hearing loss, severe hearing loss and profound hearing loss. Results: Right ear ABR results on day 7 showed statistically significant difference in hearing levels among the groups favoring steroid treatment (p<0.03). Left ear ABR results on day 7 showed no significant difference among the groups (p>0.05). Right and left ear ABR results on day 28 showed statistically significant difference in hearing levels among the groups favoring steroid treatment (p<0.02). The progression of hearing status among the categories between day 7 and 28 didn't show a significant difference among the groups (p>0.05). Conclusions: Administration of dexamethasone, especially early in the course of the disease, concurrent with antibiotics will have otoprotective effects in individuals with pneumococcal meningitis.