Pauna, Henrique F.1; Amaral, Maria Stella A.1; Cureoglu, Sebahattin2; Paparella, Michael2; Hyppolito, Miguel A.1
1 Department of Otorhinolaryngology, Head and Neck Surgery, Ribeirão Preto Medical School (FMRP-USP), University of São Paulo, Ribeirão Preto, SP, Brazil;
2 Department of Otolaryngology, Head and Neck Surgery, University of Minnesota, Minneapolis, MN, United States.
Objectives:
We aimed to demonstrate the progressive cochlear changes among patients with AOM, COM, meningitis, and a control group of human temporal bones.
Methods: This is a comparative human temporal bone study, conducted in 2016. The presence/absence of effusion, inflammatory cells, granulation tissue, and fibrosis was assessed in each midmodiolar section, as well the measurement of the basal turn of the cochlea and its segments.
Cochlear hair cells
we evaluated the number of inner and outer hair cells by using the following formula: % of hair cell loss = number of absent hair cells/number of present + absent hair cells in each turn x 100.
Stria vascularis
We measured the area of the stria vascularis in each specific turn. The results were expressed as mean area per cochlear turn, in μm2.
Spiral ganglion neurons
We counted only the spiral ganglion neurons in Rosenthal’s canal.
Statistical analysis: Chi-square test and Fisher’s exact test were used, and Mann-Whitney and Kruskal-Wallis tests were used to compare numerical variables, followed by the Dunn post-hoc test to identify the differences.
Results:
We found that basal turn, scala tympani, middle scala, scala vestibuli, and stria vascularis measures were significantly smaller in control temporal bones compared to diseased temporal bones (P<0.001).
Conclusion: We found a reduced basal turn area among normal temporal bones and larger cochlear measurements among diseased temporal bones. A larger stria vascularis area among diseased bones may be related to edema. Finally, we found a reduced number of spiral ganglion neurons among diseased temporal bones, which was significant when we compared the COM group to the control group.