Studies of human temporal bone pathologies: the NIH perspective.

Abstract

The study of human inner ear pathology, necessarily tied to autopsy studies in general, is influenced in the United States at the present time by a number of factors (and I imagine that much the same influences are at work in Europe). Virchow would turn in his grave were we even to suggest that the study of human tissue pathology and its comparison with the normal is a practice that has outlived its usefulness. Nevertheless, there are those in our field or in closely related fields who believe that light microscopic studies of human temporal bone pathology represent a pasture whose previous yield, in the ~O’S, 40’s and ~O’S, was rich, but which has by now been so thoroughly plowed that productivity is diminished to the point of cost ineffectiveness. Certainly many spectacularly effective and clinically valuable studies were carried out in those decades, but the list of otologic problems whose etiology and treatment continue to defy us and whose solutions could come from further studies of the human temporal bone, is even more impressive. A second factor influencing the study of the human inner ear is the falling autopsy rate. Numerous explanations for this decline have been offered. These include the improvements in our capability of seeing inside the intact human patient by such techniques as ultrasonography, scintigraphy , computerized tomography and now nuclear magnetic resonance scanning. In other words, we are told, disorders are now so much more readily studied during the life of the patient that an autopsy can add little more information. Would that this were true of the inner ear! Another factor influencing the autopsy rate and therefore temporal bone studies in particular, and whose full effect may not yet have been realized, is the direct result of the rising cost of medical care and the cost of maintaining teaching hospitals. Autopsies are expensive-an expense that must be born by the institution since we would find it dificult to ask patients’ relatives or medical insurance carriers to meet this particular expense. No matter how informative and fascinating autopsies can prove to be, the cold facts of current fiscal problems must be faced. Many institutions must now eliminate such sources of financial loss or face bankruptcy. This inevitably makes physicians, no matter what their past opinions may have been, far less likely than ever to urge an autopsy. Those of us who study the human inner ear, particularly its sensory epithelia, have so far benefited little from advances in in vivo clinical examination methods. But there will continue to be advances in diagnostic and therapeutic skills from which we will benefit and there will be improvements in the methods we have for harvesting and preserving and for examining human temporal bones. These advances will demand and permit, respectively, new approaches to the study of human inner ear pathology. Surface preparations are now in extensive use (these actually represent a revival of a much earlier method of examination); the micro slicing technique of Michaels will be discussed during this meeting, as will freeze fracturing; and transmission and scanning electron microscopy are beginning to be applied to studies of human inner ear material. In general terms, there is a growing and very logical tendency for the type of study proposed to determine the technique to be used. Changes in the focus of studies of the histopathology of the human inner ear are well