Mamoru Shibuya

Ultrastructural Pathology of the Middle Ear Mucosa in Otitis Media with Effusion

To elucidate the histopathological features of the middle ear mucosa in otitis media with effusion (OME), 33 specimens were obtained from OME patients (28 from children and 5 from adults) at the time of the ventilation tube insertion, and examined by light- and electron-microscopy. The mucosa from both pediatric and adult OME patients with glue effusion consisted mostly of non-ciliated cells containing numerous low electron-dense granules with or without a core, and many macroapocrine sections were observed on the apical surface of the cells. The mucosa with mucoid effusion showed various secretory activity, but macroapocrine secretions were rarely found. The intercellular space was intact and the junctional complex was well preserved. In serous otitis cases, the epithelia consisted mostly of cuboid ciliated cells and non-ciliated cells without definite secretory activity. But the intercellular space became widened and the junctional complex was occasionally damaged, indicating that the epithelium was quite permeable. We concluded that there was no significant histopathological difference between the OME mucosa of children and that of adults, although the nature of the effusion was closely correlated with the morphological features of the epithelial linings.

Pathophysiology and Prognosis of Sudden Deafness with Special Reference to the N1 Latency

Electrocochleography (ECochG) was performed in 84 patients with sudden deafness which were classified into 3 groups according to the ECochG findings, i.e. the unchanged N1 latency, the prolonged N1 latency and the absence of N1 response. The cause of hearing loss in the first group was thought to be strial, postsynaptic or mild cochlear damage and that in the second to be vascular, sensory or neural damage. The first group showed a better prognosis than those of the other two.