Ototoxicity resulting from intracochlear perfusion of Streptococcus pneumoniae in the guinea pig is modified by cefotaxime or amoxycillin pretreatment.

Acute changes in the electrophysiology and ultrastructure of the organ of Corti were studied after microperfusion of c. 5 x 10(6) CFU of serotype 2 Streptococcus pneumoniae D39 or Escherichia coli K-12 directly into the scala tympani of guinea pigs. Hearing loss was assessed by recording the auditory nerve compound action potential response to a 10 kHz tone pip. Mean hearing loss 3 h after pneumococcal perfusion (n = 4) was 44 dB, compared to 6 dB after E. coli perfusion (n = 4) (P<0.001). After pneumococcal perfusion, scanning electron microscopy revealed damage to hair cell stereocilia and cratering of the apical surface of supporting cells. Intraperitoneal injection of 100 mg/kg cefotaxime (n = 4) or 100 mg/kg amoxycillin (n = 4) 30 min before perfusion of pneumococci significantly reduced mean hearing loss to 23 dB (P=0.01) or 20 dB (P=0.01), respectively, and diminished ultrastructural damage. The data suggest that if pneumococci invade the inner ear during meningitis, cochlear deafness may rapidly ensue.

The role of corticosteroids in infants and children with bacterial meningitis.

Bacterial meningitis continues to be a cause of substantial morbidity in infants and children. Hearing impairment is the most common sequela of this disease. Corticosteroids have been used in an attempt to reduce the incidence of meningitis-induced hearing loss. Some studies have demonstrated a decrease in the incidence of hearing impairment in patients treated with cefuroxime plus dexamethasone compared with cefuroxime alone. Similar data are lacking for other frequently used antibiotics. Based on these studies, the use of dexamethasone should be considered in infants and children greater than two months of age with suspected bacterial meningitis. Critical issues including the timing of steroid initiation in relation to antibiotic therapy and the appropriate antibiotic-corticosteroid regimen must be addressed. Studies should be performed to define the exact role of corticosteroids in the treatment of bacterial meningitis. Until additional data are available, we recommend the use of dexamethasone in pediatric patients older than two months of age with bacterial meningitis.