Cochlear Changes in Chronic Otitis Media

Objectives/Hypothesis: The objective was to describe the morphological changes in the cochlea in chronic otitis media. Study Design: Retrospective human temporal bone analysis. Methods: Fifteen temporal bones with unilateral chronic otitis media were selected and compared with contralateral normal temporal bones. Standard cytocochleograms and spiral ganglion cell reconstructions were performed on all temporal bones. Spiral ligament was divided into four segments according to the locations of different types of fibrocytes. The average loss of fibrocytes in each segment was estimated. Morphometric measurements of areas of stria vascularis and spiral ligament were made in all turns of the cochlea on mid modiolar sections. Results: Loss of outer and inner hair cells was common in the basal turn of the cochlea in temporal bones with chronic otitis media compared with control ears. There was no difference in the number of spiral ganglion cells in the chronic otitis media and contralateral ears. The areas of stria vascularis and spiral ligament in the basal turn decreased significantly in the ears with chronic otitis media compared with control ears. There were no significant differences between the ears with chronic otitis media and the contralateral ears for any of the regions characterized by the presence of types I-IV fibrocytes. Conclusion: The results of the study are consistent with the hypothesis that chronic otitis media causes cochlear disease.