Pathology as it relates to ear surgery II. Labyrinthectomy.

Five human temporal bones and three surgical VIIIth nerve biopsies from patients who had previously undergone labyrinthectomy, five months to ten years before examination, were studied by light and electron microscopy. Post-labyrinthectomy dizziness could be explained on the bases of inadequate surgical removal of the vestibular sense-organs, neuroma formation in the vestibule, and high regenerative potential of the vestibular nerve. Post-labyrinthectomy pressure sensation and tinnitus are most probably due to cochlear endolymphatic hydrops and need cochlear neurectomy. The severe atrophy in the sensorineural structures of the cochlea was not associated with retrograde degeneration of the cochlear nerve central axons. This may be of significance in the artificial electrical stimulation of the cochlear nerve in deaf patients.