Systemic steroid reduces long-term hearing loss in experimental pneumococcal meningitis.
OBJECTIVE
Sensorineural hearing loss is a common complication of pneumococcal meningitis. Treatment with corticosteroids reduces inflammatory response and may thereby reduce hearing loss. However, both experimental studies and clinical trials investigating the effect of corticosteroids on hearing loss have generated conflicting results. The objective of the present study was to determine whether systemic steroid treatment had an effect on hearing loss and cochlear damage in a rat model of pneumococcal meningitis.


METHODS
Controlled animal study of acute bacterial meningitis.


METHODS
Adult rats were randomly assigned to two experimental treatment groups: a group treated with systemic steroid (n = 13) and a control group treated with saline (n = 13). Treatment was initiated 21 hours after infection and repeated once a day for three days. Hearing loss and cochlear damage were assessed by distortion product otoacoustic emissions (DPOAE), auditory brainstem response (ABR) at 16 kHz, and spiral ganglion neuron density.


RESULTS
Fifty-six days after infection, steroid treatment significantly reduced hearing loss assessed by DPOAE (P < .05; Mann-Whitney) and showed a trend toward reducing loss of viable neurons in the spiral ganglion (P = .0513; Mann-Whitney). After pooling data from day 22 with data from day 56, we found that systemic steroid treatment significantly reduced loss of spiral ganglion neurons (P = .0098; Mann-Whitney test).


CONCLUSIONS
Systemic steroid treatment reduces long-term hearing loss and loss of spiral ganglion neurons in experimental pneumococcal meningitis in adult rats. The findings support a beneficial role of anti-inflammatory agents in reducing hearing loss and cochlear damage in meningitis.
Worsøe
Lise
L
Department of Oto-rhino-laryngology, Head and Neck Surgery, Copenhagen University Hospital Gentofte, Hellerup, Denmark. l_worsoe@hotmail.com
Brandt
Christian Thomas
CT
Lund
Søren Peter
SP
Østergaard
Christian
C
Thomsen
Jens
J
Cayé-Thomasen
Per
P
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D001623:Betamethasone / Q000494:pharmacology*; D003051:Cochlea / Q000187:drug effects / Q000473:pathology; D016057:Evoked Potentials, Auditory, Brain Stem / Q000187:drug effects*; D006319:Hearing Loss, Sensorineural / Q000188:drug therapy* / Q000473:pathology; D007273:Injections, Intramuscular; D008297:Male; D008586:Meningitis, Pneumococcal / Q000188:drug therapy* / Q000473:pathology; D009474:Neurons / Q000187:drug effects / Q000473:pathology; D017084:Otoacoustic Emissions, Spontaneous / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D013136:Spiral Ganglion / Q000187:drug effects* / Q000473:pathology
D000893:Anti-Inflammatory Agents; D001623:Betamethasone