Ultrastructural study of the human utricular macula and vestibular nerve in meniére's disease.

The authors have carried out an ultrastructural study of the human utricular macula and the vestibular nerve in the internal acoustic meatus of four patients suffering from Meniere's disease. They confirm the presence of degenerative alterations in the utricular sensory epithelium. The nervous fibers situated in the supporting connective tissue of the neuro-epithelium showed modifications in the Schwann cell cytoplasm and in the arrangement of the myelin sheaths. The same alterations appear in the vestibular nerve in the internal acoustic meatus in 2 of our cases. In the other 2, the vestibular nerve was formed by a granular matrix with several myelin figures in the proximity of possible Schwann cell nucleus debris.