RADIATION AND EAR: EXPERIMENTAL STUDIES
After a review of previous reports on the effects of ionizing radiations (especially of x rays and Ra) on the ear, results are reported on the effects on the ear of exposure of Sprague-Dawley rats to 2-Mev x rays and /sup 60/Co gamma radiation. Whole-body doses of 100 to 3000 r were given and histopathologic changes in the ear were examined one to five days later. To avoid the influence of nonradiation pathology (a factor considered to be of great consequence) the findings were tabulated on basis of the infection-free material with comparative data from cases showing disease independent from the radiation effects. Hemorrhage stood out clearly as the principal damage; primary by direct, acute extravasation and secondary by damaged vessels giving way. Tympanic membrane, the mucous membrane lining of the middle ear inclusive of the ossicles, showed engorgement with extravasation. Sometimes the bone was affected by participation of the periosteum in the general process. The inner ear usually remained intact next to a heavily damaged tympanic cavity. Here, damage was manifested as vascular phenomena: perilymphatic edema with compression of the endolymphatic space in the vestibular part and destruction of the elements of the cochlear duct, with exception of the remarkably resistant tectorial membrane, by hemorrhage from the stria vascularis. The basilar and the Reissner membranes remained intact, the latter without exception remaining in the standard position. Most conspicuous was the destruction of the papilla of Corti and surrounding elements in its vicinity, while cristae, inclvsive of their cupulae, and maculae proved to be practically unaffected by radiation in the dosage used. On the other hand, the organ of Corti, while in many instances being destroyed next to intact vestibular end organs, was in other cases intact next to massive infection in the adjacent middle ear. In different cochlear turns, the organ of Corti showed different degrees of disintegration, the apical turn generally containing the organ with least damage. Previous reponts were confirmed as to hemorrhages, while earlier findings regarding the sensory end organs were difficult to evaluate because of nonradiation effects. (BBB)
- Research Organization:
- Los Angeles Foundation of Otology, Calif.
- NSA Number:
- NSA-18-019562
- OSTI ID:
- 4025434
- Journal Information:
- Acta Oto-Laryngologica, Supplementum (Sweden), Journal Name: Acta Oto-Laryngologica, Supplementum (Sweden) Vol. Vol: 184; ISSN AOLSA
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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