Stimulus coding in cochlear nucleus, noting different discharge patterns of units in different subdivisions
Healthy dogs weighing 10 to 12 kilograms were used in this experiment. Preliminary to the introduction of microemboli into the cochlear and vestibular circulation, the arterial supply to the central nervous system of the dog was studied from the radiographic and anatomic standpoint. Arteriographic studies of the basilar circulation were performed by injecting 20 cc of Angio-Conray® into the left verte-
Since the introduction of viomycin in 1950, it has been used extensively in the treatment of patients with tuberculosis.^ It is an antibiotic produced by an actinomycete, streptomyces puniceus, effec tive against myobacterium tuberculosis when given parenterally. In vitro it has some effect against other organisms, but its use has been mainly reserved for tuberculosis.^ While there is no cross resistance with streptomycin, acid fast bacilli resistant to viomycin are also resistant to kanamycin. The reverse is not true. It is thought to be about one-third as potent as streptomycin when tested in vitro. Clin ically, it has been used most often in those patients who have pre viously received INH, PAS and streptomycin.
Cancer of the middle ear is a very rare neoplasm. Various large ear, nose and throat clinics in the United States have reported that incidence may range from 1 case of cancer up to 4,000 cases, and some clinics have seen from 1 to 50,000 cases.̂ "* The middle ear thus displays a significant immunity against malignant neoplasia. Unfor tunately, this fact tends to creat the attitude that a condition so infrequent need rarely be thought of during observation of pathologic processes of the middle ear. As a result, the presence of cancer is denied until its development is obvious. However, this factor is understandable when one realizes that the physician must see literally thousands of abnormal conditions of the middle ear before encounter ing a cancer.
Six cases of congenital cholesteatoma of middle ear and mastoid are presented as a third report, thereby increasing the number of such cases reported by the author and his associates to 23. Our first case of congenital cholesteatoma of the petrous pyramid, Cawthorne type, is reported. Most importantly, five cases of recurrent cholesteatoma thought to be due to incomplete primary excision (residual cholesteatoma) are described. One postoperative retraction pocket is described as potential secondary cholesteatoma which required corrective revision surgery. In spite of relatively high incidence of revision surgery for postoperative cholesteatoma, the author reaffirms his belief in using "closed technique" to preserve near-normal external auditory canal anatomy and an intact tympanic cavity regardless of the primary fate of the ossicular chain.
@ International reference zero levels for pure-tone audiometers have been recoxumended by the International .Organization of standardization (ISO) and are under consideration for inclusion in a new American Standard for Audiometers, The new IS0 levels are desirable because: ( 1 ) the shape of the threshold contour is more accurate, (2 ) the threshold levels are more readily reproducible, and ( 3 ) they will eliminate ambiguity and confusion in the international exchange of audiometric information. The new I S 0 levels differ significantly from the American Standard values of 1951, but readings on one of these bases can readily be transferred to readings on the other base by a simple arithmetical adjustment.
The LaryngoscopeVolume 74, Issue 9 p. 1215-1219 Article Otology-art or science?† Kenneth Day M.D., Kenneth Day M.D. Pittsburgh, PaSearch for more papers by this author Kenneth Day M.D., Kenneth Day M.D. Pittsburgh, PaSearch for more papers by this author First published: September 1964 https://doi.org/10.1288/00005537-196409000-00001 † Address of Guest of Honor, Presented at the 97th Annual Meeting of the American Otological Society, Inc., San Francisco, Calif., April 5, 1964 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Volume74, Issue9September 1964Pages 1215-1219 RelatedInformation
International reference-zero levels for pure-tone audiometers have been recommended by the International Organization of Standardization (ISO) and are under consideration for inclusion in a new American Standard for Audiometers. The new ISO levels are desirable because (1) the shape of the threshold contour is more accurate, (2) the threshold levels are reproducible from laboratory to laboratory and from country to country, and (3) they represent the only apparent escape from permanent ambiguity and confusion in the international exchange of audiometric information. The new ISO levels differ significantly from the American Standard values of 1951, but readings on one of these bases can readily be transferred to readings on the other base by a simple arithmetical adjustment. For instance, for the determination of percentage impairment of the ability to hear speech by calculation from the average of the decibel readings at 500, 1000, 2000 cps, an adjustment of 11 dB in the average of these readings provides the transfer from one base to the other.
This presentation concerns the effects of replacement of the stapes by either a wire-fat graf t or a solid plastic piston. O n e migh t ask what purpose is served by making hearing measurements on cats when these operations are so commonly performed on h u m a n beings and the results measured by audiometr ic tests. First of all, this proce dure allows us t o make acute measurements before the effects of heal ing and inflammation become manifest. H u m a n audiometry in the operat ing room is not as reliable because the ea rdrum mus t be detached at the annulus, whereas in cats the operation is done th rough an a t t icotomy. Generally high noise levels prevail in most operat ing rooms and there is difficulty in applying the earphone to the ear while preserving sterile technique. More impor tan t , however, is the possi bility of mak ing measurements at suprathreshold sound pressures tha t give precise information about aspects of ear funct ion tha t cannot be determined by audiometry very well. These include phase meas urements and s tudy of the funct ion relat ing the inpu t sound pressure to the ou tpu t cochlear microphonic voltage. The method also allows direct comparison of two or more techniques on the same animal. Still another advantage is tha t it permits control of certain variables tha t cannot be ethically studied in h u m a n beings. For example, we can s tudy the effect of violent rocking of the mobile stapes in order to see if high tone hearing loss is produced.
