Temporal Bone Pathology Secondary to Head Trauma - A Human Temporal Bone Study

Hypothesis/Background:We hypothesize that following head trauma there is a difference in temporal bone (TB) pathology in cases with and without skull fracture. Although conductive, sensorineural, mixed hearing loss, and TB pathology following head trauma have been reported, to our knowledge, there are no studies that have compared the pathology of the TB in cases with and without skull fracture.Methods:We analyzed 34 TBs from donors who had a history of head trauma (20 with skull fracture and 14 without fracture), and 25 age-matched controls without clinical or histological evidence of otologic disorders. We documented the presence and location of TB fracture, ossicular injury, and cochlear hemorrhage and evaluated the loss of spiral ganglion cells and sensory hair cells, damage to the stria vascularis, and the presence of endolymphatic hydrops.Results:We found a significant loss of outer hair cells in the upper basal, lower, and upper middle turns of the cochlea (p = 0.009, =0.019, =0.040, respectively), a significant loss of spiral ganglion cells (p = 0.023), and cochlear hemorrhage predominantly in the basal turns secondary to head trauma. Interestingly, these findings were significantly observed in TBs from donors with a history of head trauma without skull fracture.Conclusion:The greatest damage was to the cochlear basal turn. Our findings suggest that head trauma may result in tonotopic high frequency sensorineural hearing loss. TBs from donors with skull fracture have less pathologic changes than those without.