Abstract
Material for electron microscopy study was obtained from a patient previously suffering from Meniere's disease and treated by ultrasound. It consisted of parts of the membranous labyrinth as well as the vestibular ganglion. The neuro-epithelium of the macula showed degenerative changes and there was marked vacuolation of the cytoplasm. The endothelial cells lining the semicircular canal showed gross vacuoles contained degenerating mitochondria and some debris which may reach the endolymph. The wall of the semi circular canal was oedematous and the basement membrane lifted off by oedematous fluid. There was obvious change in nerves and neurones. The nerves showed loosening of the myelin sheath and ballooning. The neurones contained lipoid inclusions and multicystic lysosomes. Similar inclusions were also noted in some myelinated nerves.