Histopathologic changes of contralateral human temporal bone in unilateral Ménière's disease

HYPOTHESIS: To disclose the histopathologic findings in the contralateral temporal bone in unilateral Ménière's disease. BACKGROUND: Several functional studies reported abnormal findings in the contralateral ears in patients with unilateral Ménière's disease. METHODS: This study involved quantitative analysis, including the number of spiral ganglion cells, the loss of cochlear hair cells, the area of stria vascularis, and the density of fibrocytes in the spiral ligament. It included 14 temporal bones from 7 subjects with bilateral Ménière's disease, 30 temporal bones from 15 subjects with unilateral Ménière's disease, and 17 age-matched normal control temporal bones from 12 subjects. RESULTS: The mean number of spiral ganglion cells in the contralateral temporal bones in patients with unilateral Ménière's disease was 17,376.0 and was significantly lower than that in normal controls. The mean loss of inner and outer hair cells in the contralateral temporal bones in patients with unilateral Ménière's disease was significantly greater than that in normal controls in all turns. The stria vascularis was severely atrophic and degenerated in patients with Ménière's disease. The mean area of stria vascularis in contralateral temporal bones in patients with unilateral Ménière's disease was significantly smaller than normal controls. There was no significant difference in the density of fibrocytes in the spiral ligament between the diseased side and the contralateral side in patients with unilateral Ménière's disease and between normal control and contralateral side. CONCLUSION: The contralateral inner ear in patients with unilateral Ménière's disease has significantly more damage compared with inner ears of normal controls.