Greater Cochlear Damage in Otogenic Versus Meningogenic Meningitis: Hearing Rehabilitation Implications.

Abstract

To quantify cochlear and vestibular cellular losses between cases of meningogenic and otogenic meningitis. From the archival human temporal bone collection at the University of Minnesota, we selected specimens with meningitis history and histopathological evidence of labyrinthitis. We grouped specimens into two categories (otogenic and meningogenic) based on infection route and included age-matched controls without ear or central nervous system disease. From 36 temporal bones, we quantitatively assessed outer hair cell (OHC) and inner hair cell (IHC) loss, as well as spiral ganglion neuron (SGN) and Scarpa's ganglion neuron (ScGN) counts, then compared results among groups. Both case groups demonstrated OHC loss compared with controls (p < 0.05), with more severe loss in the otogenic group versus the meningogenic group (p = 0.01). IHC loss occurred only in the otogenic group compared with both meningogenic and control groups (p = 0.019 and < 0.001, respectively). No statistically significant difference was found between IHC loss in meningogenic and control groups (p = 0.382). Both otogenic and meningogenic groups showed significant reduction of SGN and ScGN counts compared with controls (p < 0.05), with no statistically significant differences between the two meningitis groups for either measure (p = 0.993 and 0.762, respectively). Meningitis is associated with loss of cochlear hair cells, SGN and ScGN. The otogenic route demonstrated a greater loss of both IHC and OHC in comparison with the meningogenic route. N/A.