Labyrinthitis ossificans

This is the final stage of labyrinthitis.  It is characterized by ossification of the inner ear spaces. The perilymphatic spaces are usually involved and the endolymphatic spaces are often spared. The region of the scala tympani, near the round window membrane, is the area most commonly affected.  Degeneration of the stria vascularis, organ of Corti and ganglion cells is frequently seen.