Pathogenesis of hearing loss in head injury. Studies in man and experimental animals.

This study reports on the histopathologic findings in the temporal bones and brain of a patient who died of head injury. A common type of head injury in man was simulated in guinea pigs by shaking them. A hearing loss was demonstrated with Preyer reflex audiometry although the cochlear potential thresholds remained normal. Only minor pathologic changes were found in the membranous labyrinths. Laceration and hemorrhage in and around the cerebrum, rhombencephalon, and eighth nerves were noted in most of the experimental animals. Auditory manifestations following head injury may very frequently be due to damage to the central auditory pathways rather than to the end organ.