Hearing loss and extent of labyrinthine injury in Pseudomonas otitis media.

Abstract

To determine if the severity of hearing loss due to semicircular canal transection (SCT) in Pseudomonas otitis media (POM) is a function of the extent of the labyrinthine injury. POM was induced bilaterally in 45 guinea pigs. After 2 to 4 days, SCT was performed in one 1 on the horizontal canal, the superior canal, or both the horizontal and the superior canals. Auditory-evoked brainstem responses were measured before and after SCT. POM was induced bilaterally in all animals. Elevation of click thresholds was found in almost all SCT ears of all 3 groups; however, there were no significant differences between groups. Comparing the SCT ear to the contralateral, control ear, mean hearing losses in the horizontal, superior, and horizontal + superior SCT groups were 23 dB, 27 dB, and 24 dB, respectively. Hearing loss does not correlate with extent of labyrinthine injury in POM in the guinea pig. B-2.