Prevention of Hearing Loss in Experimental Pneumococcal Meningitis by Administration of Dexamethasone and Ketorolac

Abstract

Pneumococcal meningitis remains a significant cause of morbidity, particularly sensorineural hearing loss. Recent literature has suggested that a vigorous host immune response to Streptococcus [corrected] pneumoniae is responsible for much of the neurologic sequelae, including deafness, after bacterial meningitis. This study used a rabbit model of hearing loss in experimental pneumococcal meningitis to evaluate the therapeutic effect of two anti-inflammatory agents, dexamethasone and ketorolac, coadministered with ampicillin. Both adjunctive drugs minimized or prevented sensorineural hearing loss compared with placebo. Dexamethasone, administered 10 min before ampicillin, was particularly effective in minimizing mean hearing threshold change compared with placebo for both clicks (dexamethasone: 6.7-dB sound pressure level [SPL] vs. placebo: 33. 4-dB SPL, P=.0078) and 10-kHz tone bursts (dexamethasone: 8.4-dB SPL vs. placebo: 53.4-dB SPL, P=.0003). These findings support the beneficial role of anti-inflammatory agents in reducing the incidence of hearing loss from pneumococcal meningitis, especially if therapy is instituted early in the course of infection.

Limited Efficacy of Adjuvant Therapy with Dexamethasone in Preventing Hearing Loss Due to Experimental Pneumococcal Meningitis in the Infant Rat

“…We demonstrated in our study that dexamethasone is not effective in preventing SNHL in infant rats experimentally infected with S. pneumoniae at P11. Our results contrast with those of a previous report of SNHL attenuation by adjuvant dexamethasone in adult rats with PM (26). The differential response to dexamethasone in the adult and the infant rat model needs to be further investigated, but it may be due to the metabolic and growth changes taking place in the immature cochlea at the time of hearing onset (34,35).…”

“…However, data from clinical trials available at present do not allow any conclusion on the potential benefit of adjuvant dexamethasone to prevent SNHL in children with PM (12,14,16 -19,21). Experimental data on animal models of PM are scarce and limited to adults (25,26). None of them attempted to investigate the morphologic correlates of hearing loss.…”

“…None of them attempted to investigate the morphologic correlates of hearing loss. In an adult rabbit model of PM, the administration of dexamethasone 10 min before ampicillin (therapeutic regimen starting at 18 h after infection) attenuated SNHL compared with placebo, as measured by ABR 8 d after infection (26). More recently, it was reported that adjuvant dexamethasone preserved cochlear function in an adult gerbil model of PM (25).…”

“…Whereas dexamethasone was shown to decrease neurologic sequels and caspase activity in an adult rat model of PM (22), it increased both acute hippocampal injury and long-term learning deficits in adult rabbits (23) and in infant rats (24). Experimental data on the potential of adjuvant dexamethasone to prevent inner ear damage associated with PM is scarce and limited to adult animal models (25,26). To our knowledge, the present report is the first experimental study assessing the potential of dexamethasone to prevent hearing loss in an infant model of PM.…”

Multiple Complications Due to Subacute Suppurative Otitis Media

“…Without doubt, the clinical picture as well as the fluctuations in hearing loss are less prominent with the serous form that what is seen during purulent labyrinthitis. If the use of myringotomy and antibiotics does not give the expected results, corticosteroids are the treatment of choice; they are thought to provide some improvement to the residual auditory threshold (6). Unfortunately, the use of corticosteroids did not produce such results in our case.…”