Embryonic hearing organs after maternal rubella.

Three temporal bones of two four‐month embryos, operatively removed from mothers who suffered rubella in the second month of pregnancy, were histologically examined. Hyperemia and free hemorrhages were seen, while the nervous elements of the inner ear were found to be in a condition corresponding to the fetal age. This being the period in which the organ of Corti is differentiating along the basilar membrane, any possible disturbance in the delicate mechanism of adjustment, e.g. , the lagging behind of certain sections, has to be closely watched as a possible source of hearing defects. The specific infectious agent causes arrest of development of the end‐organ in the most critical period and vascular damage, possibly the latter being the primary change. Vulnerability of the vessels shows up at the end of the pregnancy in an increased tendency for birth injuries. This way a series of factors collaborate to produce the picture of defective hearing in the progeny, after rubella of the mother. As far as a survey can be given today, there are two ways in which damage results by exposure to the virus of rubella: One being arrest of development, the other vascular changes. The two can be formulated into a monistic theory by assuming that the vessels are the first to suffer, and lack in nutrition is then followed by developmental arrest. Here is a field of research of rare interest with many problems unsolved. The first decade after the basic discovery of Gregg yielded a rich crop of investigative results, among which, however, pathological findings are negligible. Aycock said that rubella now takes on the status of a disease worthy of the best in diagnosis, treatment, prevention and research. In attacking the problem of the pathology of aural damage it is desirable that the otologist should assume the leading rǒle before the initiative is definitely lost to borderline disciplines