Meniere's disease and endolymphatic hydrops without Meniere's symptoms: Temporal bone histopathology

We studied temporal bone histopathology in 21 ears with Meniere's disease a nd 24 ears with endolymphatic hydrops without Meniere's symptoms and compar ed the findings to those in 10 ears with presbycusis and 11 ears with norma l hearing. Normal hearing ears showed less degeneration of cochlear structu res than the other ears. In ears with endolymphatic hydrops without Meniere 's symptoms, the degeneration of spiral ligament, hair cells, dendrites (pe ripheral processes) and apical spiral ganglion cells was more severe than i n the other three groups. In ears with Meniere's disease and endolymphatic hydrops without Meniere's symptoms, the hair cells and dendrites were more affected than ganglion cells and there was no correlation between hair cell and ganglion cell degeneration. These findings suggest that a permanent th reshold shift in late stage endolymphatic hydrops is not related to ganglio n cell loss but rather to degeneration of sensory elements.