Temporal Bone Studies of the Human Peripheral Vestibular System

Quantitative assessments of vestibular hair cells and Scarpa's ganglion cells were performed on temporal bones from 24 patients with well-documented Meniere's disease. Of these, 18 had unilateral disease and 6 had bilateral disease. Vestibular hair cell counts were made in each of the 5 sense organs by Nomarski (differential interference contrast) microscopy. Hair cell counts were expressed as densities: number of cells per 0.01 mm2 surface area of the sensory epithelium. The results were compared with age- and sex-matched normal data. The type I hair cell densities for all vestibular sense organs were within the range for normative data. On the other hand, there was a significant loss (p < .01) of type II hair cells for all 3 cristae and both maculae. There was also a significant loss of Scarpa's ganglion cells (p < .001) when compared with normative data. The findings indicate a selective loss of type II hair cells and Scarpa's ganglion cells in Meniere's disease. These new observations have implications regarding the pathophysiological mechanism and clinical manifestations of Meniere's disease.